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GLOBAL BIOGEOGRAPHY, BIOSTRATIGRAPHY AND EVOLUTIONARY PATTERNS
OF ORDOVICIAN AND SILURIAN BRYOZOA

BY

Hichael Edward Tuckey

A DISSERTATION

Submitted to
Michigan State University
in partial fulfillment of the requirements
for the degree of

DOCTOR OF PHILOSOPHY

Department of Geology

ABSTRACT

GLOBAL BIOGEOGRAPHY, BIOSTRATIGRAPHY AND EVOLUTIONARY PATTERNS
OR ORDOVICIAN AND SILURIAN BRYOZOA

BY

Michael Edward Tuckey

The data for each of the chapters in this thesis was derived
from a global bryozoan data base assembled for this project. The
data base contains information on nearly all species of
Ordovician and Silurian Bryozoa which have been described in the
literature. The information recorded for each reported occurrence
of a species includes: geographic locality, geologic formation,
lithology of the formation, and colony morphology. Ages of
formations were estimated from recently published stratigraphic
charts. Taxonomy and synonymies of bryozoan clades were assembled
with the advice of Dr. Robert Anstey. The bibliography of sources
for the data base in contained in Appendix A.

Four independent problems were addressed in this thesis:

1) An investigation of the biogeography of Ordovician and
Silurian Bryozoa revealed the existence of four major Ordovician
bryozoans provinces: Baltic, North American, Siberian and
Mediterranean. The Llandeilo-Caradoc was a period of high
provinciality as all four provinces were in existence.
Provinciality was reduced in the Ashgill, as the North American
and Siberian and the Baltic and Mediterranean Provinces merged.
In the Llandovery and Henlock. the temperate latitude Mongolian
Province existed on the northern portion of the Siberian plate.

Silurian provinciality was reduced with the merging of the

North American—Siberian and Baltic Provinces in the Uenlock.

a) An investigation of Ordovician-Silurian radiations of the
Bryozoa revealed that the major center of origin of bryozoan
radiation in the Early Ordovician was the temperate latitude
continent of Baltica. Hithin North America, bryozoan genera
and families mad their first appearances in shallow water and
reef environments along the continental margin, while speciation
rates were highest in offshore areas of the craton.

3) The statistical technique of gradient analysis was found to
be useful for stratigraphic correlation, and faunas from Poland
and Burma were dated by this method.

4). The Late Ordovican mass extinction was found to be a
composite of three separate extinction events. The major
extinction occurred at the end of the Rawtheyan, and was
associated with a marine regression which affected primarily

species from terrigenous lithotopes.

DEDICATION

This thesis is dedicated to the numerous paleontologists
and stratigraphers who have described the Ordovician and Silurian
bryozoan faunas of the world. Their works are listed in Appendix
A. A thesis of this sort would have been unthinkable without the
years of effort and immense amounts of data generated by bryozoan
specialists of the past. Bryozoan descriptive paleontology is
approximately 100 years old, and over this time period four
individuals stand out as being extraordinarily prolific in their
description of Ordovician and Silurian faunas: G.G. Astrova,
June Ross, E.O. Ulrich and R.S. Bassler. They are truly giants

of paleontology.

ACKNOULEDGEMENTS

I would like to acknowledge Dr. Robert Anstey for his
advise and help in the formulation of the problem and for his
taxonomic expertise. I would also like to thank Feng Bing-Cheng

for his help in translating some of the Chinese literature.

TABLE OF CONTENTS

LIST OF TABLES

LIST OF FIGURES

CHAPTER ONE: BIOGEOGRAPHY OF ORDOVICIAN AND SILURIAN BRYOZOANS

CHAPTER THO:

INTRODUCTION
METHODS
ARENIG
LLANVIRN
LLANDEILO
CARADOC
ASHGILL
LLANDOVERY
HENLOCK
LUDLON
PRIDOLI
DISCUSSION
SUMMARY

TIMING AND BIOGEOGRAPHY OF THE EARLY RADIATION
OF THE BRYOZOA

INTRODUCTION

TIMING OF THE RADIATION
LATITUDE AND CENTERS OF ORIGIN
THE OFFSHORE-ONSHORE HYPOTHESIS

PALEOENVIRONMENTS OF EVOLUTIONARY CENTERS IN
NORTH AMERICA

EVOLUTION AT THE SPECIES LEVEL

vi

12

17

86

33

43

49

'36

59

be.

66

67

68

BS

88

89

97

OCEANIC ISLANDS AS EVOLUTIONARY CENTERS

DISCUSSION

SUMMARY

CHAPTER THREE: GRADIENT ANALYSIS AND BIOSTRATIGRAPHIC

CORRELATION
INTRODUCTION
METHODS
RESULTS

A DATING OF THE ORDOVICIAN ERRATIC BOULDER
FAUNA FROM POLAND ‘

A DATING OF THE NAUNGKANGYI FORMATION OF BURMA

SUMMARY

CHAPTER FOUR: THE LATE ORDOVICIAN MASS EXTINCTION

BIBLIOGRAPHY

APPENDIX A:

INTRODUCTION

ONNIAN EXTINCTIONS
RAUTHEYAN EXTINCTIONS
HIRNANTIAN EXTINCTIONS
DISCUSSION

CONCLUSION

DATA BASE BIBLIOGRAPHY

v“

100

101

106

108

109

112

113

113

115

119

120

121

122

188

138

185

136

146

Table

Table

Table

Table

Table

Table

Table

1-

Summary of
Summary of
Summary of
Endemicity

First axis
formations
First axis

formations
0.804 from

First axis
formations

of the South Shan States of Burma

LIST OF TABLES

Lower Ordovician biogeographic provinces 4

Middle Ordovician biogeographic provinces 5

Upper Ordovician biogeographic provinces 6

of bryozoan genera

DCA ordination

of Estonia

DCA ordination
of Estonia and

Poland

DCA ordination

103

scores for the Ordovician
114

scores for the Ordovician
erratic boulders 0.17 and

116

scores for the Ordovician

of Estonia and the Lower Naungkangyi
(L-Naung) and Upper Naungkangyi (U-Naung) Formations
of the North Shan States and the Naungkangyi

vi“

118

Figure
Figure
Figure
Figure
Figure
Figure
Figure

Figure

Figure

Figure

Figure
Figure
Figure
Figure
Figure

Figure

Figure

Figure
Figure
Figure

Figure

l.

8.

3.

18.

13.

14.

15.

16.

17.

18.

80.

81.

LIST OF FIGURES

Arenig DCA axes 1 vs. 8

Arenig Faunal Provinces

Llanvirn DCA axes 1 vs. 2
Ordovician geosynclinal facies map
Llanvirn Faunal Provinces
Llandeilo DCA axes 1 vs. 8
Llandeilo Faunal Provinces

Ordovician and Silurian migrations of
bryozoan genera to North America

Ordovician and Silurian migrations of
bryozoan genera to Baltica

Ordovician and Silurian migrations of
bryozoan genera to Siberia

Caradoc DCA axes 1 vs. 3
Caradoc Faunal Provinces
Ashgill DCA axes 1 vs. 8
Ashgill Faunal Provinces
Oceanic Current Patterns for the Silurian

Silurian paleogeographic reconstruction of
Ziegler et al., 1977

Late Ordovician lithofacies, midcontinental
United States

Llandovery DCA axes 1 vs. a
Llandovery Faunal Provinces
Henlock DCA axes 1 vs. 8

Uenlock Faunal Provinces

10

11

13

15

16

19

88

83

84

85

88

30

35

38

39

40

48

45

47

51

58

Figure
Figure
Figure
Figure

Figure
Figure
Figure

Figure

Figure

Figure

Figure
Figure
Figure

Figure

Figure

Figure

Figure

Figure

88.

83.

84.

85.

86.

87.

28.

29.

30.

31.

38.

33.

34.

35.

36.

37.

38.

39.

Ludlow DCA axes 1 vs. 8 55

Ludlow Faunal Provinces S7
Pridoli DCA axes 1 vs. 8 58
Pridoli Faunal Provinces 60

Originations
plate during

Originations
plate during

Originations
plate during

of bryozoan species per continental
the Ordovician and Silurian 69

of bryozoan genera per continental
the Ordovician and Silurian 70

of bryozoan families per continental
the Ordovician and Silurian 71

worldwide bryozoan speciation rates for the
Ordovician and Silurian, expressed as number
of new species per million years 73

worldwide bryozoan evolutionary rates for the
Ordovician and Silurian, expressed as number
of new genera per million years 74

worldwide bryozoan evolutionary rates for the
Ordovician and Silurian, expressed as number
of new families per million years 75

Total diversity of bryozoan species for the
Ordovician and Silurian 76

Total diversity of bryozoan genera for the
Ordovician and Silurian 77

Extinctions of bryozoan genera for the
Ordovician and Silurian 78

Number of new bryozoan species originations

per suborder

for the Ordovician and Silurian

for evolutionary fauna one 80

Speciation rates per suborder for evolutionary
fauna one for the Ordovician and Silurian 81

Number of new bryozoan species originations

per suborder

for the Ordovician and Silurian

for evolutionary fauna two. 88

Speciation rates per suborder for evolutionary
fauna two for the Ordovician and Silurian 83

Percent extinctions of Late Ashgill bryozoan
species per suborder 84

Figure

Figure

Figure

Figure

Figure

Figure

Figure

Figure

Figure

Figure

Figure

Figure

40.

41.

48.

43.

44.

45.

46.

47.

48.

49.

50.

51.

Geographic locations of first appearances

bryozoan families in North America for the

Ordovician and Silurian

Geographic locations of first appearances
bryozoan genera in North America for the
Ordovician and Silurian

Geographic locations of first appearances
bryozoan species in North America for the
Ordovician and Silurian

The Ordovician stratigraphic sequence of
Estonia

Ordovician and Silurian extinctions of
bryozoan genera recorded in intervals of
million years

Ordovician and Silurian extinctions of
bryozoan species recorded in intervals of
million years

of

90

of

98

of

98

111

183

q
184

Extinctions of Late Caradoc bryozoan species
listed as X of fauna extinct per continent 125

Extinctions of Late Caradoc bryozoan species
and genera listed as X of fauna extinct per

number of continents occupied

186

Extinctions of Late Caradoc bryozoan species
and genera listed as x of fauna extinct per

lithotope occupied
The stratigraphic stages of the Ashgill

Rawtheyan and Hirnantian extinctions of

187

189

bryozoan species in Baltica and North America
listed as X of species extinct per continent 130

Rawtheyan and Hirnantian extinctions of
bryozoan species listed as x of species
extinct per lithotope occupied

xi

131

CHAPTER ONE

BIOGEOGRAPHY OF ORDOVICIAN AND SILURIAN BRYOZOANS

INTRODUCTION

Ordovician and Silurian biogeographic histories have been
compiled for a variety of marine invertebrates. Trilobite
biogeography has been described by Hhittington (1966, 1973) and
Uhittington and Hughes (1978, 1973). Jaanusson (1973), Sheehan
(1979), Boucot and Johnson (1973) and Williams (1973) have
described brachiopod biogeography. The biogeography of
graptolites has been discussed by Skevington (1973) and Berry
(1973, 1979). Other organisms such as corals (Kaljo and Klaaman,
1973), conodonts (Bergstrom, 1973 and Lindstrom, 1976),
palynomorphs (Cramer and Diaz, 1974), echinoderms (Paul, 1976;
Hitzke, Frest and Strimple, 1979), molluscs (Pojeta, 1979;

Rohr, 1979) and stromatoporoids (Nebby, 1980) have also been
subjects of biogeographic analysis. General reviews of Ordovician
and Silurian biogeography have been provided by Ziegler et a1.
(1977), Jaanusson (1979), Boucot (1979), Burrett (1973) and
Spjeldnaes (1981). Although each group of organisms has its own
biogeographic history, similarities are evident in the patterns
of distribution of all major groups.

The Ordovician can be characterized as a period of high
provinciality, with biogeographic differentiation being greatest
in the Lower to Lower Middle Ordovician. An abrupt change
occurred in the Hirnantian (Latest Ashgill), and Silurian faunas
are known to be highly cosmopolitan. For some organisms, a

gradual decrease in provinciality became evident as early as

3

Caradoc time (Williams, 1973). These changes in provinciality
are related to the changing positions of the continents, as the
Iapetus Ocean was gradually closing through the Ordovician
into the Silurian and the continent Baltica was moving from a
temperate southerly latitude towards North America and the
equator. This paper summarizes Ordovician biogeographic
distributions for a number of marine invertebrates (Tables 1—3).
Bryozoan biogeography has not been studied in detail
for the Ordovician and Silurian Periods. Ross (1985) published a
short descriptive paper on Ordovician bryozoan biogeography,
Anstey (1986) described Late Ordovician North American bryozoan
biogeography and Astrova (1965) and Nekhorosheva (1976)
described Ordovician bryozoan biogeography of the Soviet
Arctic. The following analysis is an attempt at a detailed
biogeographic history of the bryozoa, with an analysis of each
stage of the Ordovician and Silurian, using quantitative
techniques and data drawn from a global bryozoan data base of 495

sources newly compiled for this project.

METHODS

The multivariate statistical techniques of reciprocal
averaging, detrended correspondence analysis and cluster
analysis were used to quantitatively determine biogeographic
associations. Gradient analysis methods, such as reciprocal

averaging, have been used extensively in community ecology and

Table 1. Summary

Locality

of Lower Ordovician biogeographic provinces.

8

3 4

{Brachiopods Brachiopods Trilobites Graptolites

 

NA. Midcontinent
NA. Geosyncline
Baltic Platform
Ural Geosyncline
Siberian Platform
Altai Sayan
Northeast USSR
Australia

Hales

Montagne Noire
North Africa
China

1. Jaanusson, 1973

8. Hilliams, 1973

3. Hhittington, 1973
4. Skevington, 1973

Abbreviations: NA.=North America,
Anglo-Frn.=Anglo-French,

Hungaiid-Calymenid,

Northern
Northern
Baltic

Baltic

Northern
Northern
Northern
Northern
Southern
Southern

Northern

Scoto-Appl.
Baltic

NE. USSR

Anglo-Frn.
Anglo—Frn.

 

i Bathyuridl
: Bathyurid:
i Asaphid i
l Asaphid 3
i Bathyuridi
: Bathyurid:
lHung-Caly.l
(Selenopel.l
(Selenopel.l

:Selenopel.:
lHung-Caly.i

Pacific
Pacific
Atlantic

Pacific
Atlantic

Atlantic
Pacific

Scoto-Appl.=Scoto—Appalachian
Selenopel.=Selenopeltis,
NE.= Northeast

Hung-Caly.=

.
.1

Table 8. Summary of Middle Ordovician biogeographic provinces.

 

1 8 3 4
Locality (Brachiopods Brachiopods Corals Conodonts
NA Midcontinent :8. Northern: American : Amer—Sib.lNA Midcont.
NA Geosyncline {Scoto—Appl.: America : Amer-Sib.: European
Baltic platform 3 Baltic : Baltic :Euro-Asianl European
Ural Geosyncline :Scoto—Appl.: : :
Siberian Platform :C. Northern: American : Amer-Sib.:NA Midcont.
Altai Sayan :Scoto-Appl.: :Euro-Asian:
Northeast USSR lScoto-Appl.i American 1 Amer-Sib.l
Australia 1 l l i Austral.
Hales : Southern (Anglo-Frn. (Euro-Asian: European
North Africa : Southern 1 Bohemian : :
Southern Europe l Southern 1 Baltic l 3
Burma : l Baltic : :
Bohemia : : Bohemia : i

l. Jaanusson, 1973

8. Hilliams, 1973

3. Kaljo and Klaaman, 1973
4. Bergstrom, 1973

Abbreviations: NA.=North America, C.=Central, Scoto-Appl.=
Scoto-Appalachian, Anglo-Frn.=Anglo-French, Amer-Sib.=
American—Siberian, Austral.=Australian

Table 3. Summary of Upper Ordovician biogeographic provinces.

 

1 2 3 4
Locality :Brachiopods Brachiopods Trilobites Corals
NA. Midcontinent (C. NorthernlMid-AmericaiMono-Remo.lAmer-Sib.
NA. App. Geosyn. :C. NorthernlN. Europe :Mono-Remo.:
Baltic Platform lHibern-Sal.:N. EurOpe lMono—Remo.lEuro—Asian
Ural Geosyncline : : :Mono-Remo.:
Siberian Platform :8. Northern: lMono—Remo.lAmer-Sib.
Altai Sayan (Hibern—Sa1.: : (Euro-Asian
Northeast USSR lHibern—Sal.l {Mono—Remo.:
Australia : : :Plio-Caly.l
Hales : :N. Europe :Tri-Homal.lEuro—Asian
Montagne Noire : l lTri-Homa1.:
Ireland :Hibern-Sal.l : :
Anticosti :Hibern-Sal.lN. American: :
Alaska lHibern-Sal.l : 1
Missouri (Hibern-Sal.: : 1
North Africa : : Bohemian lTri-Homal.:
Bohemia : l Bohemian l lEuro-Asian
China : : :Plio-Caly.l

1. Jaanusson, 1973

8. Hilliams, 1973

3. Nhittington, 1973

4. Kaljo and Klaaman, 1973

Abbreviations: NA.=North America, App. Geosyn.=Appalachian
geosyncline, Hibern—Sal.=Hiberno-Salairian, C.=Central, N.=
North, Tri-Homal.= Trinucleid-Homalonotid, Plio-Caly=Pliomerina-
Calymenid, Mono-Remo.=Monorakid-Remopleuridid, Amer-Sib.=
American-Siberian

7

are similar to factor analysis in that they reduce the
dimensionality of the data matrix. The samples are ordinated
along a gradient between two poles (the samples most ‘
distant from each other along the axis). Reciprocal
averaging has been used by Cisne and Rabe (1978) and Anstey,
'Rabbio and Tuckey (1987a) in Ordovician paleoecological studies.
Another gradient analysis method, polar ordination, was used by
Raymond (1987) to define Devonian phytogeographic provinces
and by Anstey, Rabbio and Tuckey (1987a) in paleoecological
studies. Detrended correspondence analysis (hereafter called
DCA) was used by Anstey, Rabbio and Tuckey (1987b) in a
study of Late Ordovician paleocommunities. This method is an
improvement on reciprocal averaging in that subsequent axes
beyond the first axis are truly orthogonal, whereas in reciprocal
averaging, the second, third and fourth axes are often correlated
with the first axis. A summary of these techniques is provided in
Gauch (1988).

In this study, DCA proved to be the most useful
technique for distinguishing biogeographic units. The input
data matrix for DCA was composed of the number of species
per genus present at each locality. DCA was run with a
separate data matrix for each stage of the Ordovician and
Silurian. Localities of low diversity were not included in the
analysis, with the minimum diversity being 5 to 8 genera,
depending on the overall diversity of the stage. Because of the
limited number of localities and overall low diversity of the

Arenig, low diversity localities were included in that analysis.

Geographic patterns were generally distinguishable on plots of
locality scores for DCA axes one vs. two. Occasionally
biogeographic patterns were obscured by the effects of facies, so
for the Caradoc, patterns were most easily distinguishable on
plots of DCA axes one vs. three. -

Cluster analysis was used by Williams (1973) to define
Ordovician brachiopod provinces and by Raymond (1987) to help
define Devonian phytogeographic provinces. Cluster analysis
differs from gradient analysis in that it measures overall
faunal similarity, and endemic genera, which may be
characteristic of a particular province, have no special
weight. In this study cluster analysis was used as a backup
method to lend support to, or modify gradient analytic methods.
The input data matrix for the cluster analysis consisted of a
matrix of Simpson’s indices of faunal similarity. Clustering was
also done with data matrices of Jaccard coefficients; however
Simpson’s Index gave results more congruent with the gradient
analysis methods. The clustering method used was the average
linkage between group method. In keeping with previous Ordovician
and Silurian biogeographic studies, the term, province, is used
in this paper to refer to a biota characteristic of a particular
continent, although present day provinces are often restricted
to small portions of a continent. Geographic associations within
continents, restricted to major lithotopes, are referred to as

biomes, following Anstey (1986).

ARENIG

Except for one species (Ceramopora unapensis) described by
Ross (1966a) from the Kindblade Formation (Late Tremadoc) of
Oklahoma, bryozoa are first found in rocks of Arenigian age.
However, a Tremadocian fauna from China is currently being
decribed by Spjeldnaes and Hu (Taylor and Cope, 1987).

The most diverse Arenig bryozoan fauna is found in Baltica

in the 81 and B8 horizons of Estonia and Leningrad and in the
Nelidov horizon of Novaya Zemlya. Less diverse faunas are found
in North America in the Kanosh Shale in Utah, the Arenig-Llanvirn
Oil Creek Formation in Oklahoma and the Late Arenig Shinbrook
Formation in Maine. Faunas are also known in Central China and
the North Urals. The species Sagenella vetera is known from
Bohemia and Alwynopong oroggmnus and a generically indeterminate
species have been recorded from Ireland.

Baltic faunas are related by the common presence of
Dianulites at all localities and the presence of Ditto ora,
Esthoniopo:§_and Nicholsongllg at two or more localities.
Oklahoma, Utah and Maine are united by the common presence of
Batostoma, which does not appear in Baltica. North American
and Baltic Provinces are clearly distinguishable on a plot of
locality scores for DCA axes one vs. two (Figure 1). China
is allied faunistically with North America by the presence of
Batostoma and is provisionally assigned to the North American

Province (Figure 8).

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12

LLANVIRN

During the Llanvirn, bryozoan faunas increased in both
diversity and provinciality. The Baltic Province shows increased
diversities of bryozoans from the B3, Cla and C1b horizons of
Estonia and Leningrad, the Khydey Formation of the North Urals
and the Yuno Yaga horizon in the Novaya Zemlya-Vaygach-Pay Khoy
region. These faunas are characterized by Dianulites, Di lotr a,
Hemiphragma, Nicholsonella and Stictoporg. The North American
Province consists of bryozoans from the Oil Creek and McLish
Formations of Oklahoma, the Chazyan Day Point and Lower Mingan
Formations in the Lake Champlain and Mingan Island areas, and
the Lower Lenoir Formation of Virginia. North American faunas are
again characterized by the common presence of Batostoma at all
localities. Other common North American genera are Phylloooring,
Stictopora, Monotrygella, Chasmatogora, Nicholsonella and
Eridotrypg, Bryozoans also appear in the Elgenchak and
Labistakskaya Formations at Sette Daban on the Eastern Siberian
margin. Provinces are defined on the plot of DCA axes one vs.
two (Figure 3).

Along with provinciality, subprovinces or biomes (Anstey,
1986) can also be observed in the data. The Baltic Province can
be subdivided into two different facies associations or biomes.
Leningrad and Estonia occur in the Baltic Platform Biome and
the North Urals and the Novaya Zemlya-Vaygach-Pay Khoy regions

occur in the Uralian Geosynclinal Biome. Approximate positions of

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ISIXV

14
geosynclinal and platform facies for the Ordovician, of Siberia,
North America and Baltica, with the island of Novaya Zemlya
observable in the northern part of the Uralian geosynclinal
facies are shown in Figure 4. Virginia, as part of the
Appalachian Geosynclinal Biome is distinguishable from other
North American localities and shares common genera with both
Baltica and Siberia. Its location on the North American
continental margin apparently makes it a possible colonization
site for migrants crossing the Iapetus Ocean. The genera
Cyphotrypg_and Monotryga, which were endemic to Baltica in the
Arenig, appear in Virginia in the Llanvirn. Conversely,
Phyllodictyg, which was endemic to Utah in the Arenig, appears in
Estonia in the Llanvirn, indicating that a limited amount of
migration across the Iapetus was occuring at this time.
Provinces are plotted in their approximate paleogeographic
positions in Figure 5.

A cluster analysis of Llanvirn localities, gave results
similar to gradient analysis, as clusters representing the
Chazyan Reef Biome, the Uralian Geosynclinal Biome and the Baltic
Platform Biome appeared. Virginia clustered more closely with
Sette Daban than with other North American localities. Its
association with Sette Daban is represented by the dotted line

connecting the two localities (Figure 3).

15

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17
LLANDEILO

The provincial patterns of the Llanvirn carry through to the
Llandeilo, although there is some blurring of provincial
boundaries due to migration, and an increasing differention of
North American faunas is seen. Provinces are defined on plots
of DCA axes one vs. two (Figure 6). Localities in the Baltic
Province cluster with high scores on axis one, with faunas
occuring in the Clc and C8 horizons in Estonia and Leningrad, and
in the Dyrovataya horizon in the Novaya Zemlya-Vaygach-Pay Khoy
region. Leningrad, however, has a somewhat endemic fauna,
with the endemic genera Scenellopora, Arthrogtylug, and
Hexaporites. Arenig-Llanvirn genera such as Dianulites,
Diolotrypgy Egthoniopora and Hemiphragma continue to be common
and new genera such as Egchydictyg, Egrvohglloporg, Graptodictya
and Mesotrypa appear. The Novaya Zemlya-Vaygach-Pay Khoy area
shows an increasing faunal affinity with North America,
particularly with Appalachian shelf localities. Faunal
similarities between geosynclinal localities on widely separated
continents reflect the presence of many cosmopolitan genera at
these sites. Virginia, Novaya Zemlya and Alabama share the common
genera Nicholsonella, Egchydictyg, Egrvohalloporg, and
Stictogora, indicating an increase in migration across a
narrowing Iapetus Ocean. Alabama and Morocco were closely linked
with Vaygach-Novaya Zemlya in the cluster analysis (dotted lines
connect these localities in Figure 6).

The Siberian Province contains localities clustering with

18

Figure 6. Llandeilo DCA axes 1 vs. 8. Symbols: A=Alabama,
E=Estonia, K=Kotel Island, L=Leningrad, LC=Lake Champlain,
LR=Leni River, =Morocco, MI=Mingan Island, O=Oklahoma,
=Podkammenaya Tunguska River, =Montreal, T=Taimir, V=Virginia,
VR=Viluya River, Z=Novaya Zemyla-Vaygach-Paykhoy. Dotted lines
connecting localities across provincial boundaries indicate
additional faunal similarities detected by cluster analysis.

19

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ISIXV

20
low scores on DCA axis one. Faunas occur in the Krivolutski
and’Lower Mangazeyski stages in the Podkammenaya-Tunguska, Leni
and Viluya River valleys on the Siberian Platform, the Engelgardt
horizon on the Taimir Peninsula and in the Lower Malodiring
horizon on Kotel Island. Common Siberian genera are Batostoma,
Nicholsonella, Triqonodictyg, Stictooorg, Phaenogorella and
Sibirgdictyg.

The North American Province consists of localities having
intermediate scores on DCA axis one and is further
differentiated into two subprovinces, or biomes on axis two.
The Chazyan Reef Biome consists of faunas from the Crown Point
and Lower Valcour Formations of the Champlain Basin, the Crown
Point and Laval Formations at Montreal, Quebec, and the Upper
Mingan Formation at Mingan Island. Common genera in this biome

are cryptostomes such as Stictooora, Chasmatopora, Phylloporing

 

and Pachydictxa, and the trepostomes Monotrypella and Batostoma.
The North American Geosynclinal Biome consists of faunas from the
Upper Lenoir, Lower Effna, New Market and Lincolnshire Formations
of the Appalachian shelf in Virginia and Alabama, and the Upper
McLish and Tulip Creek Formations of the Simpson Group in the
Arbuckle Mountains of Oklahoma. Ross (1976) stated that the
Simpson Group strata were deposited in a rift zone or

aulacogen, extending northward from the Ouachita continental
margin. Faunal similarities between Oklahoma and the Appalachian
shelf region may be explained by existence of a continuous
Appalachian-Ouachita shelf biome.

These trends are similar to those which have been found in

21

the distributions of brachiopods and trilobites. The Scoto-
Appalachian fauna, which is found in Scotland and in the
Appalachians east of the Helena-Saltville Thrust, has an
amphicratonic distribution, as a similar fauna has been reported
from the west side of the craton, and a related fauna occurs in
the Novaya Zemlya-Pay Khoy region (Jaanusson, 1979). This echoes
the similarities between the bryozoan faunas of Virginia, Alabama
and Novaya Zemlya.

A fourth faunal province, the Mediterranean Province, is
represented by the Llandeilo faunas of Morocco. North Africa is
placed at the approximate position of the South Pole in
paleogeographic reconstructions (Figure 7), and its faunas
have been linked to those of Southern Europe (Spjeldnaes, 1981).
Spjeldnaes has suggested that Mediterranean and Baltic Provinces
were separated by a climatic barrier rather than by a wide ocean.
This is supported by the cluster linkage in Figure 6, in which
Morocco is linked with Novaya Zemyla.

Migration patterns to the continents of North America,
Baltica and Siberia during the Ordovician and Silurian were
established by comparing estimated first appearances of genera on
each continent (Figures 8-10). The Llandeilo is an epoch of high
migration of genera into all three continents. Spjeldnaes
(1981) identified this migration as the first major faunal
exchange across the Iapetus Ocean. Migrations occurred in a
variety of marine invertebrate groups including cephalopods,
trilobites and brachiopods. Bryozoans seem have migrated in

many directions, contrary to Spjeldnaes’ assertion that the

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26

exchange was one-sided, with few Baltic forms appearing in

North America.

CARADOC

The four Llandeilian provinces are again seen in the Caradoc
(Figure 11). The Siberian Province consists of faunas from the
Upper Mangazeyski and Dolborski horizons of the Siberian
Platform, the Tolmachev horizon from Taimir, the Upper Malodiring
horizon from Kotel Island and the Kulonskaya and Vodopadnenskaya
horizons from Sette Daban. Also included in the Siberian Province
are faunas from the geosynclinal regions of the Siberian plate in
the Altai Sayan, Tuva and Manchuria. Cluster analysis also groups
'Siberian localities with the exception of the Altai Sayan and
Tuva, which are linked with the St. Lawrence River Valley.

These localities share the genera Batostoma, Ceramogora,
Constellarig, Eridotryoa, Hemi hra ma, Homotrypa, Nicholsgnella
and Parvghallopora. These localities also cluster closely with
Uralian geosynclinal localities (North Urals and

Novaya Zemyla-Vaygach), again emphasizing the similarity of

shelf faunas from the three major plates. The Siberian province
is characterized by endemic genera such as Insi nia,
Qarinodictyg, Phaeno orella, Sibiredictya and Ensipora.

The Mediterranean Province includes faunas from the Bohdalec
Shales of Bohemia and from the Caradoc of Sardinia and the Carnic
Alps. These localities have distinctive genera such as

Monotrygella and the endemic Polyteichus.

27

Figure 11. Caradoc DCA axes 1 vs. 3. Symbols: A=Australia,
a=Alabama, AS=Altai Sayan, B=Bohemia, b=Burma, CA=Carnic Alps,
ck=Central Kentucky, ct=Central Tennessee, E=Estonia, et=East

Tennessee, g=Georgia, i=Iowa, K=Kotel Island, k=Kansas, lc=Lake
Champlain, LR=Leni River, m=Minnesota, ma=Maryland, mf=Meaford,

mi=Manitoulin Island, MN=Manchuria, ms=Missouri, N=Norway,
n=Central New York, nf=Newfoundland, ni=Northwest Illinois,
nk=North Kentucky, NU=North Urals, O=Oeland, o=Oklahoma,
ot=Ottawa, P=Podkammenaya Tunguska River, p=Pennsylvania,

S=Sweden, SA=Sardinia, SD=Sette Daban, si=South Indiana, sl=St.
Lawrence River Valley, sm=Southwest Mackenzie, sn=Southeast New
York, so=South Ohio, T=Taimir, t=Toronto, TU=Tuva, v=Virginia,
W=Wales-England, w=Wisconsin, VR=Viluya River, Z=Novaya Zemyla-
Vaygach-Pay Khoy. Dotted lines Connecting localities across
provincial boundaries indicate additional faunal similarities
detected by cluster analysis.

28

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29

The Baltic Province consists of faunas from Estonia, the
North Urals, the Novaya Zemlya-Vaygach—Pay Khoy area, the
Scandinavian island of Oeland, Sweden, Norway, England-Wales,
Burma, Southeast New York and Newfoundland. The fauna from the
Naungkangyi shales of Burma seems to have its greatest affinities
with the Baltic Province. Williams (1973) also classified Burma
with the Baltic Province on the basis of its brachiopods. Burma,
as part of a Southeast Asian microcontinent, is geographically
distant from Baltica (Figure 18).

Spjeldnaes (1981) raised the possibility of an “anti-boreal”
fauna existing in the Northern Hemisphere resembling the south-
temperate Baltic fauna of the Southern Hemisphere. Evidence for
the existence of this fauna comes from the occurrence of
brachipods with Baltic affinities in the Klamath Mountains of
California and Alaska. The Baltic bryozoan species Earvohallogora

tolli, native to Estonia, was reported from the Caradoc of the

 

Inyo Mountains in California by Pestana (1960), and from the
Caradoc of Gaspe, Quebec by Fritz (1941). The fauna from the
Southwest McKenzie mountains in Western Canada also has Baltic
affinities as indicated by the cluster analysis. Bergstrom (1973)
reported that Ordovician conodonts in the Appalachians and in the
western Cordilleran regions of North America also have Baltic
affinities, differing from the North American midcontinent fauna.
Bergstrom attributed these differences to climatic zonation,
suggesting that the North American continent was rotated 90
degrees from its present position, with the equator running

through the midcontinent and the west and east coasts situated in

30

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31
the north and south temperate zones, respectively. These findings
appear to support the ”anti-boreal“ fauna hypothesis. however,
most of these localities represent exotic terranes, and their
Ordovician paleogeographic positions are uncertain.

Western Newfoundland, Southeast New York and Southern
England-Hales are also included in the Baltic Province. The fauna
from Newfoundland ‘is from the autochthonous region of Hestern
Newfoundland. This region was part of the North American plate
and its Baltic affinities support Sheehan’s (1975) contention
that some Baltic brachiopods also lived in the open ocean and
occupied habitats around the North American continental margin.
The Southeastern New York fauna is also a continental margin
fauna, which is found in the Balmville Limestone and the
Rysedorph Hill Conglomerate. The Rysedorph Hill Conglomerate has
been interpreted as an allochthonous outer shelf deposit. which
was transported westward during the Taconic Orogeny (Vollmer and
Bosworth, 1984). The existence of this "open-ocean fauna“ may
explain the recurrent faunal similarities between the
geosynclinal localities in the Urals, the Altai Sayan and the
Appalachians during~ the Ordovician. This may be a better
explanation of why exotic terranes, such as Burma, have Baltic
faunas. These shelf faunas also retain a local imprint. as
Newfoundland is grouped most closely with Lake Champlain in the
cluster analysis, and Southeast New York is. linked with
Hinnesota. In general, shelf faunas have been grouped as a part
of the same biogeographic province as their neighboring platform

faunas by gradient analysis.

32

Southern England-Hales, located close to the North American
plate (Figure 12), has a cosmopolitan bryozoan fauna which has
affinities with both Baltica and North America. Seven of the nine
genera present are shared with both Estonia and Northern
Kentucky. Consequently England~Uales clusters closely with
localities from the Cincinnati region in North America, but has
been classified with the Baltic Province by DCA. Bergstrom
(1973) also reported that Upper Middle Ordovician conodont faunas
from Hales contained North American midcontinent elements that
distinguished them from the rest of the Baltic Province.

In the North American Province, the Cincinnati Biome,
previously recognized by Anstey (1986), can be distinguished. The
Cincinnati Biome is composed of faunas from the Lower Kope
Formation (Late Caradoc) of Southern Indiana, Southern Ohio and
Central and Northern Kentucky. Anstey reported the Cincinnati
Biome extended from Northern Kentucky to Southern Ontario in
the Late Ordovician. However, in the Late Caradoc it is in
its incipient . stages of development and is geographically
restricted to the Cincinnati area.

Australia is tentatively grouped with the North American
province, but due to the low diversity of its fauna, its
biogeographic affinities remain problematical.

Two waves of faunal migrations occurred during the Caradoc.
An early Caradoc (Black River) migration event appears to have
taken place in Baltica, North America and Siberia, while a
smaller Late Caradoc migration event affected Siberia and

Baltica (Figures 8-10). Spjeldnaes (1981) also recognized

33

the Late Caradoc event (which he termed the Vasalemma wave in
reference to the Vasalemma beds in Estonia), as being

characterized by a migration of American forms into Baltica.

ASHGILL

The Ashgill brought about a significant change in bryozoan
faunas as a breakdown in Caradoc provinciality occurred and a
more cosmopolitan fauna began to emerge. Ashgill provinces are
delineated by DCA axes one vs. two (Figure 13). Two Ashgillian
provinces are discernible: a North American-Siberian Province and
a Baltic-Mediterranean Province.

The majority of Siberian localities are allied with North
America during the Ashgill; however, the Taimir Peninsula,
located on the southern tip of the Siberian plate was
geographically adjacent to Baltica during the Ashgill (Figure
14), and its faunas from the Korotkin horizon have Baltic
affinities . Although the width of the Iapetus ocean has narrowed
considerably, the Baltic Province is still recognizable, as its
faunas from Sweden, Norway, Hales, Estonia, Gotland and Novaya
Zemlya-Vaygach-Pay Khoy are distinguishable from those of North
America. Also included in the Baltic Province is the Ashgill
fauna from Montagne Noire, southern France, which indicates that
the Mediterranean and Baltic Provinces have merged. Sheehan
(1979) noted that brachiopods from the Mediterranean Province

became abundant in Sweden during the Ashgill. He believed that

3‘}

Figure 13. Ashgill DCA axes 1 vs. 2. Symbols: a=Alabama,
ai=Anticosti Island, AS=Altai Sayan, bi=Baffin Island, C=South
China, ck=Central Kentucky, CM=Central Mongolia, ct=Central

Tennessee, E=Estonia, ei=Northeast Illinois, G=Greenland,
g=Georgia, BO=Got1and, I=Ireland, i=Iowa, mf=Meaford,
mi=Manitoulin Island, MN=Montagne Noire, ms=Missouri,
mt=Manitoba, N=Norway, n=New York, nk=North Kentucky,
NM=Northwest Mongolia, S=Sweden, si=South Indiana, sl=St.
Lawrence River Valley, SM=South Mongolia, so=South Ohio,
T=Taimir, t=Toronto, TU=Tuva, up=Michigan Upper Peninsula,
v=Virginia, H=Hales, w=Hisconsin, wt=Uest Texas, wy=Uyoming,
Z=Novaya Zemyla—Vaygach-Pay Khoy. Dotted lines connecting
localities across provincial boundaries indicate additional

faunal similarities detected by cluster analysis.

35

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I SIXV

36
cold-water Mediterranean genera moved northward with cold water
masses associated with the Ashgillian glaciation in North Africa.
However, Hhittington (1973) noted the appearance of Mediterranean
type trilobites (Selenopeltis fauna) in Baltica as early as
Caradoc time.

The fauna from the Portrane Limestone of Ireland is also
grouped with the Baltic Province although this fauna is
distinctive, as it includes the rare genera Discosgarsa and
Ichthyorachis. The Portrane Limestone is known to be an exotic
terrane representing a volcanic island in the Iapetus Ocean
(Neuman, 1984). Neuman has found that many brachiopod genera made
their first appearances on oceanic islands.

Missouri-Southern Illinois clusters with the Baltic
Province, and much of its fauna is from the Rawtheyan—Hirnantian
age Girardeau Limestone. The Baltic Province conforms well with
the Hiberno-Salarian fauna of Jaanusson (1973). This brachiopod
fauna occurs in carbonate rocks in Sweden, Norway and Ireland
and also in the Altai Sayan and in coastal North American
localities such as Anticosti Island and Perce, Quebec, Alaska
and California. A -brachiopod fauna described by Amsden (1974)
from the Noix limestone of Eastern Missouri and Western Illinois
also has Hiberno-Salairian affinities (Jaanusson 1973). The
existence of a Baltic fauna in the continental interior of the
United States reflects the increasing cosmopolitanism of the Late
Ashgill. The Hirnantian Stage (Latest Ashgill) is associated
with a low diversity “Hirnantian fauna" characterized by the

brachiopods Hirnantia and Dalmanella and the trilobite

37

Dalmanitina. The fauna, occurring in mudstones, is extremely
widespread geographically and has been reported from Bohemia,
Sweden, Ireland, England, Maine, Morocco, the Carnic Alps, Libya,
Quebec, Kazakhstan, Scotland, China, Kolyma, and Anticosti Island
(Rong 1984).

Ashgillian faunas from the Siberian localities of Tuva, the
Altai Sayan, and Northern, Central and Southern Mongolia are
grouped with. those of North American localities by gradient
analysis and particularly resemble faunas from the carbonate
platform Red River-Stony Mountain Biome localities of Greenland,
Baffin Island, Manitoba, Hyoming, Anticosti Island and Nest
Texas. Distances between the Altai Sayan-Mongolia regions of the
North Siberian plate and Canada and Greenland were not far
(Figure 14) and oceanic currents (Figure 15) may have facilitated
migration between the two areas. The Altai Sayan also shares
faunal similarities with nearby Novaya Zemyla-Vaygach, as
indicated in the cluster analysis. Kaljo and Klaaman (1973) also
have recognized Late Ordovician North American-Siberian and
European Provinces for fossil corals.

Also included in the North American-Siberian Province is a
fauna from Southern China. Similarities between faunas from
Southern China and North America—Siberia suggest an alternative
paleogeographic reconstruction (Figure 16) may be more
applicable. In this reconstruction the South China plate is
positioned in the mid-Pacific, close to the western margin of
North America.

Nithin the North American plate, the Late Ordovician biomes

38

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41

of Anstey (1986) can be recognized. The carbonate platform Red
River-Stony Mountain Biome is represented by the closely grouped
localities of Anticosti Island, Nest Texas, Hyoming, and Manitoba
(Figure 13). Anticosti Island and nearby Baffin Island have been
grouped with the Baltic Province by the cluster analysis as many
of the localities in the Red River-Stony Mountain Biome have
typical Baltic genera. The Maquoketa Biome is represented by the
grouping ‘of Hisconsin, Northwestern Illinois, Northeastern
Illinois and Central Tennessee, and was recognized as a subunit
of the Red River-Stony Mountain Biome by Anstey (1986). The
terrigenous Cincinnati Biome has expanded in size since the
Caradoc and now includes Georgia, Alabama, the St. Lawrence River
Valley, Virginia, Iowa, New York, Manitoulin Island, the Upper
Peninsula of Michigan, Toronto and Meaford Ontario, Southern
Ohio, Southern Indiana and Central and Northern Kentucky. These
localities conform remarkably well to the terrigenous areas of
the Upper Ordovician lithofacies map (Figure 17).

A migration wave of largely North American genera into
Baltica took place during the Hirnantian (Figures 8-10).
Spjeldnaes (1981) has recognized this event as the "Porkuni wave“
in reference to the Porkuni Stage (Hirnantian) of Estonia. This
wave of migration probably contributed to the increasing

cosmopolitanism of Hirnantian faunas.

1&2

 

 

 

 

 

 

Figure 17

Late Ordovician lithofacies, midcontinental United

States, adapted from Frey,

1987.

CARBONATE PLATFORMS

BASINS

2!:

MUD—BOTTOM SHELVES

.....
.....

FLUVIAL—DELTAIC PLAINS

1&3
LLANDOVERY

Although still faunally distinct, the North American-
Siberian and Baltic Provinces have .begun to merge during the
Llandovery. Faunal provinces are defined on plots of IDEA axes
one vs. two (Figure 18). With further closing of the Iapetus
Ocean, the Baltic province has extended its range and now
includes Anticosti Island, on the Northeast coast of North
America. Llandoverian formations of Anticosti Island and the

Baltic Island of Gotland have these genera in common: As ero ora,

Ceramogora, Corypotrypg, Cuneatogora, nghotrxga, Fenestella,
Glauconomella, Hallogora, Nematogora, Phaenogora, Ptilodictxa,
ngicggcinigg, Thamniscus and Eridotrypg. Sheehan (1975) found
that North American and Baltic brachiopod provinces merged in the
Llandovery when Baltic genera invaded the North American
continent following the Late Ordovician extinctions. North
America, Baltica and Siberia all received relatively large
numbers of immigrants during the Llandovery (Figures 8-10). Eight
genera from the Ashgill of Baltica, Asgerogora, Clathrogora,
Cheilotrxga, Eridotrygella, Fistuligora, Hennigogora, Rhinogora
and Thamniscus newly appear on the North American continent
during the Llandovery. Three of these genera, Asperogora,
Cheilotrxga and Thamniscus newly appear at Anticosti Island,
giving the fauna a Baltic aspect.

The North American-Siberian Province includes localities

from the Podkammenaya-Tunguska and Viluya River Valleys of the

M

Figure 18. Llandovery DCA axes 1 vs. 2. Symbols: ai=Anticosti
Island, C=Central China, ck=Central Kentucky, E=Estonia,
GO=Gotland, mf=Meaford, =Norway, n=New York, nf=Ontario-Niagara
Falls Region, nk=North Kentucky, NM=Northwest Mongolia,
o=Oklahoma, P=Podkammenaya Tunguska River, PO=Podolia, si=South

Indiana, so=South Ohio, t=Toronto te=Tennessee. TU=Tuva,
up=Michigan Upper Peninsula VR=Viluya River. Dotted lines between
localities across provincial boundaries indicate additional

faunal similarities detected by cluster analysis.

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1&6

Siberian Platform, and the midcontinent regions of North America.
The biome partitioning evident in the Ordovician of the North
American continent is not present in the Llandovery, as all

North American localities were former members of the

Ashgillian Cincinnati Biome. The only North American locality
remaining from the Ashgillian Red River-Stony Mountain Biome is
Anticosti Island. A lack of faunas from other localities within
the Red River-Stony Mountain Biome leaves the question as to
whether the entire Red River-Stony Mountain Biome took on a
Baltic aspect in the Llandovery, subject to additional analysis.
The cluster analysis grouped Siberian Platform localities with
the Baltic Province, as indicated by the dotted lines. The
Podkammenaya-Tunguska River Valley locality shares 5 of its 7
genera with Norway, however it also shares 5 genera with Meaford,
Ontario. This. reflects the cosmopolitanism of many genera in the
Llandovery. Appearing in the Llandovery is a third faunal
province, the Mongolian Province, which contains faunas from
Tuva, Northwestern Mongolia and Central China. Podolia was

linked with this province by the cluster analysis. Tuva and
Northwestern Mongolia were situated on the northern portion of
the Siberian plate, while Central China rests on the South China
plate. Faunal provinces of the Llandovery are plotted on the
Silurian paleocontinental reconstruction (Figure 19). Silurian
brachiopods show a similar provincialism in this region as Boucot
and Johnson (1973) described a provincial Tuvaella Community
fauna from the Late Llandovery-Henlock of Southeast Kazakhstan,

Tuva, the Altai Mountains, Mongolia and Manchuria. Ziegler et al

#7

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(19??) believe that Silurian provinciality was caused by climatic
zonation, with the Mongolian region situated in the north
temperate realm. A comparison of paleocontinental reconstructions
for the Ashgill and Llandovery (Figs. 14 and 19) reveals that the
Siberian continent moved northward during this time interval and
provinciality may have developed as the nvrthern portion of the
Siberian plate moved into north temperate realms in the Late
Llandovery.

The fauna from central China is a low diversity fauna of S
genera from the Late Llandovery Cuijiago and Lojoping Formations
of Northern Sichuan and Southern Shaanxi provinces. Because of
its low diversity, biogeographic conclusions are tentative.
However, its affinities with the Mongolian Province in the
Llandovery, and also in the Henlock may indicate that the South
China plate was also in a north temperate latitude at this time.
Scotese (1986) positioned South China near the equator, in
accordance with Early Cambrian and Permian paleomagnetic data.
South China’s faunal similarity with Mongolia in the Llandovery
and Henlock suggest that it may have drifted northward in the
Ordovician-Silurian and returned to an equatorial latitude by
the Permian.

Podolia (Nest Ukraine) is regarded as belonging to the
Baltic province, although it shares two genera in common with
Central China, Fistuligora and Hennigogora. Podolia was located
on the southern portion of the Baltic plate at this time and the
faunal affinities between Podolia and the Mongolian province can

perhaps be explained by the similar Late Llandovery ages of their

1+9

faunas rather than by geographic proximity.

HENLOCK

During the Nenlock, the merging of the Baltic and North
American-Siberian Provinces was completed. All Baltic and North
American localities group as a single cluster (Figure 20).

Also included in the Baltic-North American-Siberian Province is a
fauna from the Nenlock of Kazakhstan. Kazakhstan is pictured as a
separate continent located in the tropical climatic zone east of

Baltica and North America (Figure 21). Baltic and North American
localities share a number of common genera in the Nenlock, among

them: Asgerogora, Ceramogora, Corynotrypg, Fenestella,
Fistuligora, Hallogora, Monotryga, Ptilodictya and Sagenella.

A somewhat unusual fauna was described from Northwest Illinois

by Grubbs (1939). This fauna occurred in the Niagaran reefs of
the Racine Dolomite, of Nenlock—Ludlow age, and included endemic
genera such as Pholidogora and Arthrogtylug.

Also reappearing in the Nenlock is the Mongolian faunal
province from the northern Siberian plate. The province is
composed of faunas from the Uenlock of Northwest Mongolia, Tuva,
East Mongolia and Central China. There appears to have been some
longitudinal zonation in this province, as Tuva and Northwest

Mongolia, on the northeastern side of the Siberian plate have

50

Figure 20. Henlock DCA axes 1 vs. 2. Symbols: ai=Anticosti
Island, C=Central China, ci=Central Indiana, E=Estonia, EM=East
Mongolia, EN=England, GO=Gotland, K2=Kazakhstan, mf=Meaford,
N=Norway, n=Hestern New York, nf=Ontario—Niagara Falls Area,
ni=Northwest Illinois, NM=Northwest Mongolia, PO=Podolia,
si=South Indiana, te=Tennessee, TU=Tuva, up=Michigan Upper
Peninsula. Dotted lines connecting localities across provincial
boundaries indicate additional faunal similarities detected by
cluster analysis.

51

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53

faunal similarities, while East Mongolia, on the northwest side
of the Siberian plate has greater faunal affinities with Central
China, which suggests a paleogeographic position for South China
as indicated in Figure 16, although at a more northerly latitude.
Podolia was again linked with the Mongolian Province in the
cluster analysis.

The complete merging of the North American and Baltic
Provinces in the Nenlock slightly preceded closing of the Iapetus
Ocean, as Late Silurian folding in Scotland and Norway suggests
that the Northern Iapetus had closed by Ludlow or Pridoli time

(Cocks and McKerrow, 1973).

LUDLDH

The Ludlow was a time of cosmopolitanism among the Bryozoa.
The Mongolian Province of Llandovery-Henlock time has disappeared
as faunas from Mongolia and Tuva now show high faunal
similarities with European and American faunas (Figure 22).
Distinctive faunas again occur in the Niagaran reefs of Northwest
Illinois, and also in the nganhebu and Xibiehu Formations of
Inner Mongolia. Ludlovian faunal gradients are controlled
by the presence of distinctive faunas at single localities rather
than by provinciality. The fauna from Inner Mongolia was located

on the North China plate, and contains the genera Ana hra ma.

54

Figure 22. Ludlow DCA axes 1 vs. 2. Symbols: A=Australia,
B=Bohemia, ca=Canadian Arctic. d=Dolgiy Island. E=Estonia,
EN=England, GO=Gotland, i=North Indiana, IM=Inner Mongolia,
MN=Montagne Noire. mv=Moldaviag ni=Northwest Illinois,
NM=Northwest Mongolia, PO=Podolia, S=Sweden, SM=South Mongolia,
te=Tennessee, TU=Tuva, w=wisconsin, Z=Novaya Zemyla-Vaygach-Pay
Khoy..

55

 

 

 

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56
Eridotrypg, Homotrxga, Paralioclema and Stictoporg. Although
Llandoverian-Henlock faunas from the South China plate had faunal
similarities with the Mongolia-Tuva region, this fauna from the
North China plate is distinctive in nature.

The cosmopolitan Baltic-North American-Siberian Province
consists of faunas from Southern and Northwest Mongolia, Tuva,
Gotland, Novaya Zemlya-Vaygach-Pay Khoy, Podolia, Sweden,
Estonia. Moldavia, England. Tennessee. Arctic Canada, Australia.
Wisconsin. Northern Indiana, Northwest Illinois. Bohemia and
Montagne Noire (Figure 83). These localities show a high degree
of similarity to one another and contain common Late Silurian

genera such as Fistuligora. Fenestella, Hallopora and Honotrxga.

PRIDOLI

The cosmopolitanism of the Ludlow continued into the
Pridoli. There is little biogeographic differentiation into
provinces among faunas from Estonia, Podolia, Gotland, Northwest
Mongolia, South Mongolia, Pennsylvania, Maryland. Nest Virginia,
New York, Oklahoma and Tuva (Figure 24). The fauna from the

Taugantelyski Formation of Tuva shows a high degree of
dissimilarity with other faunas. It is a low diversity fauna of 5
genera: Amplexogora. Eridotrypgllg, Eridotrvpg, Heterotrxga and

Stigmatella. This fauna has a distinctly Ordovician aspect to it

 

 

 

 

 

 

 

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59
as most of these genera were abundant in the Caradoc and Ashgill.
However, Ludlovian faunas from Tuva also contain these
“Ordovician” genera along with more typical Silurian genera such
as Fistuligora. Hallogora and Lioclema.

Another highly endemic fauna is found in the reef community
of the Hamra Formation in Gotland. Along with Fenestella and
Fistulipora are found the endemic genera Saffordotaxis.
Flabellotrxga and Sagenella. These faunas from Tuva and Gotland
are interpreted to be communities within the cosmopolitan Baltic-
North American-Siberian Province. Pridoli faunal provinces are

shown in Figure 25.

DISCUSSION

Patterns in the biogeographic distribution of the bryozoa
are generally consistent with those found in other fossil groups
and can‘ be explained by continental convergence and latitudinal
climatic gradients. However many interesting questions are raised
by anomalous patterns of distribution, such as the presence of a
Baltic fauna in the Ashgill of Missouri, and the presence of
Baltic faunas on both the.east and west coasts of North America
and in Burma.

Spjeldnaes (1981) and Bergstrom (1973) explained the
presence of Baltic brachiopod and conodont faunas on the west

coast of North America by hypothesizing that the west coast of

 

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61

North America was above the equator in the north temperate zone.
The coastal faunas were believed to be temperate (antiboreal)
faunas, which mirrored the south-temperate (boreal) Baltic
faunas. This idea is not supported by the continental
reconstructions of Scotese (1986), however, as the west

coast of North America is projected to be lying in equatorial
latitudes through the Ordovician and Silurian Periods. Also,

many of the fossiliferous localities on the west coast are
believed to be exotic terranes. The Klamath Mountain region,
where a Baltic brachiopod fauna has been found, has been
interpreted to be the remnants of an island arc, which was
separated from the continent by a marginal basin (Potter et al.,
1977). Nur and Ben Avraham (1977) suggested that allochthonous
terranes in western North America are remnants of a
microcontinent called Pacifica originally located near Australia.
Other island arc faunas, such as those of the Portrane Limestone,
have also been classified as being of Baltic affinity.

Faunas from Newfoundland, Southeast New York and Anticosti
Island, on the North American east coast, have also been linked
with Baltica. Mitchell (1986) stated that the Shan Plateau area
of Burma was part of a Western Southeast Asia microcontinent
island arc system which collided with Eastern Southeast Asia in
the Triassic. Thus it appears that the Baltic fauna was an open
ocean fauna inhabiting islands and continental margin localities,
as well as the Baltic platform, as Sheehan (1975) stated for
brachiopods, and was not confined to temperate latitudes.

The Baltic nature of the Missouri Ashgillian fauna has

62

previously been recognized in formations of Latest Ordovician
(Hirnantian) age by Amsden (1974, brachiopods) and by Elias
(1982, corals). Elias labeled this region of Missouri, Illinois,
and, tentatively, Northeastern Oklahoma, as the Edgewood.
Province, and suggested that the fauna migrated into this region
from the south during the Late Hirnantian transgression, which
resulted from deglaciation. However, the bryozoan fauna in this
region is found in the Fernvale, Maquoketa, Orchard Creek and
Girardeau Formations, which range from Mid Ashgill to Early
Hirnantian in age. This indicates that the Baltic fauna migrated
in at a much earlier time than has previously been recognized.
Caradocian faunas in this region are similar to those recognized
elsewhere in the Midcontinent; therefore the migration of Baltic
bryozoan faunas into this region probably occurred in the Mid
Ashgill.

The Missouri-Southern Illinois region is near the northern
extent of the Mississippi Embayment, and is a seismically active
zone, which was the site of the New Madrid Earthquake. Crustal
instability in this region is related to the presence of a Late'
Precambrian rift zone, termed the Reelfoot Rift (Ervin and
McGinnis, 1975). Precambrian rifting gave way to the development
of the Reelfoot Basin in Cambrian-Ordovician time (Schwalb,
1969). The depositional center of the Reelfoot Basin was located
in western Tennessee in the Cambrian. By the Early Ordovician,
the center of deposition had moved northward into Hestern
Kentucky, and .by Silurian time the center of the basin was

located in Southern Illinois. Schwalb has dated the timing of

63
basin development through a series of isopach maps, and related
the thick accumulation of Maquoketa sediments to a downwarping of
the basin which occurred after deposition of the Caradoc age
Kimmswick Limestone. Elevation of the adjacent Ozark and
Nashville Domes was associated with 'basin subsidence through
lateral displacement of mantle material from beneath the rift.

The development of the Reelfoot Basin may be related to
the migration of the Baltic fauna into the Missouri-Southern
Illinois region. First appearances of Baltic genera in this
region occurred during Maquoketa time, which coincides with
evidence for Maquoketa basin subsidence. Perhaps basin subsidence
allowed free migration of Baltic continental margin faunas into
the Reelfoot Basin. This biogeographic information may be
regarded as an independent test for the timing of basin
subsidence. A Baltic brachiopod fauna was described from the
Hirnantian age Keel Formation in the Arbuckle Mountains of
Oklahoma by Amsden (1974). The Arbuckle Mountain region is also
the site of a Precambrian rift zone which developed into an
Ordovician basin (Ross, 1976). Perhaps migration of Baltic
brachiopods into this region was related to synchronous Late
Ordovician basinal subsidence in Oklahoma.

The Reelfoot Basin evidently provided a source for some
migration of Baltic genera into adjacent areas of the continental
interior which led to the formation of the Maquoketa Biome. The
Baltica genera Diglotrzpa and Sceptrogora newly appeared in the
Missouri-Southern Illinois area during Maquoketa time, and

simultaneously appeared in several of the areas which constitute

610

the Maquoketa Biome (Northwest Illinois, Northeast Illinois,
Hisconsin and. Central Tennessee). Anstey (1986) also noted the
predominance of Baltoscandian genera in the Maquoketa Biome.
Although most biomes can be related to differences in
lithofacies, the presence of Baltic immigrants differentiates the
Maquoketa Biome from the Red River-Stony Mountain Biome in
Ashgillian carbonate terranes in North America. Nitzke (1987)
attributed Maquoketa phosphorite deposition in the midcontinent
to a transgression in which poorly oxygenated water upwelling at
the Ouachita continental margin deposited the phosphatic shales
and limestones of the basal Maquoketa. The subsiding Reelfoot
Basin may have provided a nearer source for the upwelling of
poorly oxygenated water. The Maquoketa transgression may also
have carried bryozoan larvae from the basin to nearby areas on

the craton, providing immigrants to the Maquoketa Biome.

SUMMARY

Bryozoan biogeography reflects many of the same patterns
observed in earlier studies of brachiopods and trilobites.
Provinciality is high in the Middle Ordovician, with four
provinces recognizable in the Llandeilo and Caradoc (North
American, Baltic, Siberian and Mediterranean). In the Ashgill, a
cosmopolitan fauna emerged as two provinces are recognizable: A

North American—Siberian Province and a Baltic-Mediterranean

6S

Province.

The merging of the North American-Siberian and Baltic
Provinces took place in the Silurian with continued closing of
the Iapetus Ocean. This merging was a gradual process however, as
Western Newfoundland and Southeast New York had Baltic affinities
as early as Caradoc time. In the Mid Ashgill, the midcontinent
Missouri-Southern Illinois area took on a Baltic aspect, and in
the Llandovery, the Anticosti Island fauna had Baltic affinities.
However, North American localities_ in the midcontinent areas of
Cincinnati, Ohio, Tennessee, New York and Ontario remained
provincial even in the Llandovery, although several Baltic genera
migrated to North America at this time. It was not until the
Henlock when North America, Siberia and Baltica coalesced into a
single province. This complete merging of Baltic and North
American bryozoan faunas postdated the merging of brachiopod and
trilobite faunas, perhaps due to a lower migratory capacity for
the bryozoa, or possibly due to more powerful quantitative
techniques of discrimination used in this study.

Climatic zonation appears to have been important in the
development of provinciality in the Silurian, as a north-
temperate Mongolian Province developed on the northern portion of
the Siberian plate and extended to the northern portion of the
‘South China plate in the Llandovery and Nenlock. The Silurian
closes with a cosmopolitan fauna showing no provinciality in the

Ludlow and Pridoli.

CHAPTER THO

TIMING AND BIOGEOGRAPHY OF THE EARLY RADIATION OF THE BRYOZOA

66

67

INTRODUCTION

Bryozoans first appeared in the Lower Ordovician, and like
many other groups in Sepkoski’s (1981) Paleozoic Fauna, greatly
diversified in the Middle Ordovician. Diverse faunas have been
described from three major continental plates: North America,
Baltica and Siberia, and smaller faunas have been described from
Southern Europe, North Africa, Australia, China, and the British
Isles. Hithin continental plates, faunas often differ from
geosynclinal shelf localities to localities on the continental
platform. A major extinction took place in the Late Ordovician,
and global diversity dropped significantly. The major orders of
Bryozoa show differences in the timing of their radiations, with
the trepostomes being most abundant in the Ordovician and
declining in the Silurian relative to the other groups. In the
following review, the early radiation of the Bryozoa is examined
through an analysis of the first appearances of 2156 species of
bryozoans recorded from the Ordovician and Silurian strata of the
world. These data are then used to test hypotheses on the
environmental and geographic factors involved in evolutionary

innovations.

68

TIMING OF THE RADIATION

The earliest recorded bryozoan was described from the Late
Tremadoc Kindblade Formation of Oklahoma (Ross, 1966a). Bryozoan
diversity gradually expanded in the Arenig, Llanvirn and
Llandeilo before reaching its maximum in the Caradoc. Early
Ordovician originations were greatest in Baltica; however the
major radiation during the Middle Ordovican was most prominent on
the North American plate. In North America, 464 new species and
31 new genera have been described from Caradocian sediments,
although only two new families appeared (Figures 26, 27 and 28).

The Caradoc radiations coincide with a major eustatic
transgression, which began in the Llandeilo and inundated the
cratonic interior of North America. This Caradocian transgression
has also been reported from the British Isles and Poland
(McKerrow, 1979 and Leggett et al, 1981). The role of
transgressions in inducing radiations was predicted by Fortey
(1984), who associated the flooding of cratonic interiors and
formation of epeiric seas with rapid increases in rates of
speciation in epicontinental areas, due to spatial heterogeneity
and the ”species area effect". Cooper (1977) also related marine
transgressions to biotic diversification and increased rates of
evolution. However the subsequent Llandoverian transgression was

not associated with a major radiation.

63

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Diversification at the species level continued in the
Ashgill of North America, as 276 new species have been described;
however only seven new genera were reported from North America
during the Ashgill. The rate of speciation was actually highest
during the Llandeilo, in the early stages of the transgression,
as approximately 47 new species per million years appeared
(Figures 29, 30 and 31). Due to the short duration of the
Llandeilo (approximately 4 Ma), the absolute number of new
species originating is much less than the Caradoc. Following the
Llandeilo, the Caradoc and Ashgill have remarkably similar rates
of evolution of new species (approximately 32 new species/Ma)
Rates of evolution of new genera were highest in the Llandeilo
and Llanvirn.

Following the Ashgill, evolutionary rates dropped
considerably in the Silurian, again remaining remarkably constant
through the Llandovery, Henlock and Ludlow at 23 new species/Ma.
Although total diversity dropped considerably following the Late
Ashgill extinctions (Figures 32 and 33), no major
rediversification of the Bryozoa is seen in the Llandovery. This
depression of the speciation rate may be related to the high
incidence of generic extinction observed in the Uenlock through
Pridoli (Figure 34), as existing genera may have gradually
dwindled by not producing enough new species to replace
extinctions. The low evolutionary rates observed in the Silurian
may also be related to the decreasing Silurian provinciality

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faunas: fauna one-suborders which radiated during the Ordovician;
and fauna two-suborders which radiated following the Late
Ordovician extinctions (Anstey, personal communication).
Suborders in fauna one experienced a major rise in speciation
rate during the Llandeilo and had their highest absolute numbers
of originations during the Caradoc (Figures 35 and 36). Suborders
in fauna two had higher speciation rates in the Silurian, with
the exception of the Amplexoporina, which diversified greatly in
the Caradoc (Figures 37 and 38). The Late Ashgill extinctions
seemed to have a pronounced effect on evolutionary rates of the
trepostomes, as post extinction speciation rates were
approximately halved in the suborders Halloporina and
Amplexoporina, and remained at low levels for the remainder of
the Silurian. The cryptostome suborders Rhabdomesina.
Fenestellina, and Ptilodictyina and the cystoporate suborder
Fistuliporina. however, experienced increases in speciation rates
from the Ashgill to the Llandovery. Trepostome suborders show
very low species survivorship into the Silurian (Figure 39). and
it is possible that the great reduction in trepostome diversity
caused by the Late Ashgill extinctions is related to the reduced
speciation rates observed in the Silurian. Gould and Galloway
(1980) observed a similar major effect in the Permian mass
extinction on brachiopods in the Mesozoic and Cenozoic. It
appears that the Late Ashgill mass extinction was an event from
which the trepostomes never recovered. The cryptostomes
experienced the highest percentage survivorship into the

Llandovery; however, their speciation rates began to decline

”—1..

80

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throughout the remainder of the Silurian. Both cystoporate
suborders (Fistuliporina and Ceramoporina) were greatly affected
by the mass extinction; however the fistuuliporines did not
suffer a depression of speciation rates in the Llandovery and
began diversifying at higher rates in hthe Henlock and Ludlow,

until a Pridoli decline.

LATITUDE AND CENTERS OF ORIGIN

Darlington (1957) first proposed that the tropics serve as a
center for the evolution of new taxa. Since that time much
research has been done to test this hypothesis for marine
invertebrates. Stehli and Hells (1971) and Durazzi and Stehli
(1972) found that the average ages of recent coral and benthonic
foraminifera genera decreased towards the tropics, while
diversity increased. They concluded that a strong relationship
exists between diversity, temperature and evolutionary rates. and
proposed a model in which the highest generic diversities
correspond with regions of highest temperature in the tropics.
New genera evolve in regions of high diversity and extend their
ranges through time into regions of lower diversity and higher
stress. Hecht and Agan (1972) also found a relationship between
age and diversity of recent and Miocene bivalve genera, with the
tropics again having higher diversities and younger generic ages.
Recent Bryozoa, however, have highest species diversities at

temperate latitudes between 30 and 60 degrees north of the

86
equator (Schopf, 1970).

Zinsmeister and Feldman (1984) proposed high latitude,

shallow water. high stress environments to be centers of origin
for new taxa. from studies of first appearances of Late Cenozoic
molluscs. echinoderms and arthropods from Antarctica.
Hickey et al. (1983) proposed Arctic origins for numerous Late
Cretaceous and Early Tertiary land plants and vertebrates. Both
studies stated that polar climatic conditions in the Cretaceous
and Early Tertiary -were mild in comparison with modern
conditions. However Zinsmeister and Feldman emphasized that the
climate was subject to extreme seasonality. They suggested that
the seasonality and isolation of the Antarctic region were the
primary cause of evolution of new taxa.

An opportunity to test these opposing hypotheses on
latitudinal effects on evolutionary innovation is provided
by documenting the early evolutionary history of the Bryozoa.

The early evolution and radiation of the Bryozoa took place on
latitudinally separated continents in the Early to Early-Middle
Ordovician. Continental reconstructions from Scotese (1986)
reveal that from the Late Cambrian to the Llanvirn, the
continents of North America and Siberia were situated in
equatorial realms, North Africa and Southern Europe were situated
near the South Pole, and Baltica was situated in intermediate
latitudes. between 30 and 60 degrees south of the equator.

By Ashgill time. however. Baltica had moved into equatorial
latitudes.

Although a few Early Ordovician species have been recorded

87

from China, the predominant record of early bryozoan evolution is
preserved in the Early Ordovician sediments of Baltica, North
America and Siberia. Diversities in the polar continents of

North Africa and Southern Europe are low. Climatically, North
America has been characterized by Spjeldnaes (1981) as having

an equatorial, low latitude climate, while Baltica had a boreal
or intermediate climate. Jaanusson (1978) also concluded that
Baltica occupied a temperate climatic zone,‘ despite the presence
of widespread carbonate deposition. Lindstrom (1978) reported
ice-marked sand grains from the Lower Ordovician of Scandinavia,
indicating that the region did experience some cold climatic
conditions. From the Arenig through the Llanvirn, when Baltica
was situated in the south temperate zone, a total of 18 families,
47 genera and 90 species made their first appearances on Baltica.
During this same time period only 6 families, 24 genera and 23
species appeared on the equatorially located North America, while
0 families, 3 genera and 8 species appeared in Siberia. Only

1 family, 1 genus and 1 species are recorded as appearing in

the polar South Europe-North Africa region (Figures 26, 87 and
28).

The fact that the relatively high latitude, temperate,
continent of Baltica served as the major evolutionary center for
the Bryozoa lends support to the generality of the patterns
observed by Zinsmeister and Feldman and Hickey et al. This
indicates that high latitude, temperate, environments subject to

extreme seasonality may be important centers ,of origin for new

taxa. In the bryozoa, this effect seems to be particularly

88
pronounced at the family level. Hebby (1984b) also suggested

a probable Baltic temperate latitude origin for the Bryozoa.

THE OFFSHORE-ONSHORE HYPOTHESIS

Sepkoski (1981), in a factor analysis of the number of
families within classes of Phanerozoic metazoans, defined three
evolutionary faunas: (1) a Cambrian fauna dominated by trilobites
and inarticulate brachiopods; (a) a Paleozoic fauna dominated by
articulate brachiopods, crinoids, ostracodes, anthozoans,
cephalopods and stenolaemate bryozoans; and (3) a modern fauna
dominated by molluscs, echinoids, gymnolaemate bryozoans, bony
fish, sharks, demosponges and malacostracean crustaceans.
Sepkoski and Sheehan (1988), Sepkoski and Miller (1985) and
Jablonski et al. (1988) found that the Paleozoic and modern
faunas appear to have had their origins in nearshore environments
and then expanded offshore with time. They suggested that
nearshore environments may be conducive to diversification,
possibly because of the frequent disturbances and stressful
conditions found there, despite higher speciation rates offshore.

An effort was made to test their hypothesis by tabulating
the geographic locations of first appearances of bryozoan taxa
in Ordovician and Silurian formations of North America. Estimated
ages of North American formations were taken from the
stratigraphic correlation charts of Ross et al. (1988), Barnes

et al. (1981) and Berry and Boucot (1970). Global first

89
appearances of bryozoan families and genera are strongly
concentrated around the ancient continental margins of North
America (Figures 40 and 41; taxa which appeared at an earlier
time on other continents were not included). Locations which
have high concentrations of originations include: Lake Champlain
(18 genera and 2 families), the Arbuckle Hountains in Oklahoma
(9 genera and 2 families), Nest-Central Utah (6 genera and 3
families), Southwest Virginia (11 genera and 1 family) and
East Tennessee (6 genera). Also, six generic originations were
recorded from the midcontinental region of Southern Indiana,

most of which were found in the Osgood Formation (Silurian).

PALEOENVIRONNENTS OF EVOLUTIONARY CENTERS IN NORTH AHERICA

The Champlain Basin in New York and Vermont was the major
apparent evolutionary center for North American Ordovician
bryozoan genera. Faunas appear to have originated in the Day
Point and Crown Point Formations of Llanvirn and Llandeilo age,
and are associated with abundant carbonate reefs. Pitcher (1964)
described these reefs as being formed in shallow water. Shallow
water indicators include: quartz silt in the matrix of reefs,
carbonate grainstones, oolites, oncolites, crossbedding and
quartz sand bars in equivalent beds. Walker and Ferrigno (1973)
classified these reefs as being located onshelf, analogous to

modern shelf patch reefs.

90

Figure 40. Geographic locations of first appearances of
bryozoan families in North America for the Ordovician
and Silurian. The 2-family contour line parallels
the ancient continental margin. Scale: one inch =
approximately 650 kilometers.

91

 

Figure 40

92

Figure 41. Geographic locations of first appearances of
bryozoan genera in North America for the Ordovician
and Silurian. The 6-genera contour line parallels
the ancient continental margin. Scale: one inch =
approximately 650 kilometers.

93

 

94

In Virginia, bryozoans originate mainly in the Llanvirn
through Caradoc New Market, Lenoir and Edinburg Formations.
Fichter and Diecchio (1986) and Read (1980) have classified the
New Market as representing shallow intertidal to subtidal
deposits, the Lenoir as representing a shallow, subtidal
carbonate ramp facies, and the Edinburg as a shelf edge facies
containing carbonate turbidites. The Edinburg contains six of the
11 generic first appearances; however, Fichter and Diecchi state
that most of the Edinburg fauna has been transported from the
shallow shelf as turbidites. Thus it is likely that the Virginia
fauna represents shallow water conditions, although it is
questionable whether the fauna is derived from the innermost
shelf.

Six genera and three families appear in the Arenig-Llanvirn
Kanosh and Lehman Formations of the Pogonip Group in Nest-Central
Utah. Hintze (1951) described the Pogonip. Group as containing
large amounts of fine quartz arenaceous material and shallow
water indicators such as intraformational conglomerates, ripple
marks, cross laminations and beds of worn and sorted trilobite
fragments. Hintze concluded that the area lay near the eastern
shore of an epeiric sea.

In Oklahoma, the majority of new taxa are found in the
Llanvirn through Caradoc Simpson Group of the Arbuckle Mountains.
The bryozoan bearing. formations of the Simpson Group are the
McLish, Oil Creek, Tulip Creek and Bromide Formations. Ham (1969)
described the Simpson Group as a sequence of formations, each of

which contains a basal sandstone, overlain by skeletal

95

calcarenites, carbonate mudstones and shales. Bryozoans are found
in the upper shale and limestone units of each formation. The
Simpson is regarded as being a transitional group of intermediate
depth, which can be differentiated from the underlying shallow
water Arbuckle Group by the absence of hemispherical
stromatolites and from the overlying deep water Viola Limestone,
by the absence of graptolites. However, the McLish has been noted
to contain Girvanella oncolites in great concentrations. The
oldest bryozoan known was described by Ross (1966a) from the Late
Tremadoc Kindblade Formation of Oklahoma. The species Ceramogora
unapensis was found in a carbonate mound unit containing abundant
lithistid sponges, quasisponges, orthid brachiopods and the blue
green alga Girvanella.

The fauna from East Tennessee is found in a large reef from
the Lower Caradoc Holston formation. Six genera make their first
appearances in the fauna. The reef fauna was described by Halker
and Ferrigno (1973), who interpreted the paleoenvironment to be
offshore, on the eastern edge of a carbonate shelf.

In summary, first appearances of bryozoan genera and
families are highly concentrated around the ancient continental
margin of North America. The most diverse localities can be
classified into three paleoenvironmental units:

1. Reefs or carbonate mounds are present in the Chazy Group
of Lake Champlain, the Holston Formation of East Tennessee
and the Kindblade Formation of Oklahoma.

8. Indicators of shallow water or inner shelf conditions are

found in the Chazy Group of Lake Champlain, the Pogonip Group

96

of Utah, the New Market Formation of Virginia and the McLish
Formation of Oklahoma.

3. Intermediate mid-shelf envirnoments have been inferred for
the Simpson Group of Oklahoma and the Lenoir Formation of
Virginia. The fauna of the Edinburg Formation was most likely
transported as turbidites into deeper waters, from shallower,
on-shelf localities.

This evidence from first appearances of bryozoan species and
genera does lend some support to the hypothesis that nearshore
environments serve as localities Ifor the origination of higher
taxa. However, some mid-shelf localities also seem to be
evolutionary centers. Reef environments seem to be particularly
important centers for the evolution of new taxa. Previous
research on the onshore—offshore problem only focused on level-
bottom communities and did not include reef communities, because
of an implicit assumption that reef communities had a different
evolutionary history than level-bottom communities. Sheehan
(1985), however, stated that reefs follow the general
evolutionary patterns of level-bottom communities. Reefs and
level-bottom communities do show an interchange of fauna as, taxa
originating in reefs radiated into level—bottom communities. It
would not be surprising if other elements of the Paleozoic fauna,
particularly corals, have similar first appearances of higher

taxa in reefs.

'97

EVOLUTION AT THE SPECIES LEVEL

Bryozoan speciation patterns in North America differ greatly
from patterns of origination of genera and families (Figure 48).
Coastal localities, which were evolutionary centers for genera
and families, have relatively low numbers .of species
originations. The highest number of species originations is
concentrated in the Cincinnati region, where bryozoans appear in
abundance in the Late Ordovician Kope and Dillsboro Formations of
Southern Indiana, Southern Ohio and Northern Kentucky. Anstey,
Rabbio and Tuckey (1987a) suggested this intracratonic region lay
in an area of relatively deeper water, centered between the
Taconic clastic wedge to the east and the carbonate platform to
the west. Other regions of high species originations include mid»
craton areas such as the Middle Ordovician formations of the
Central Tennessee Basin, the Middle Ordovician formations of
Minnesota, and Middle Ordovician and Silurian strata in Central
and Hestern New York. These results clearly imply that species-
level evolution is not preferentially concentrated in nearshore
environments. Similar results have been reported by Jablonski
(1980) and Jackson (1974), who found that offshore bivalve taxa

have higher speciation rates than onshore taxa.

Figure 48. Geographic locations of first appearances of
bryozoan species in North America for the Ordovician
and Silurian. The 60-species contour line outlines
cratonic localities in Minnesota, Central Tennessee,
Southern Indiana, Northern Kentucky and Central and

Uestern New York. Scale: one inch = approximately
650 kilometers.

99

N: mcnm_u

 

100

OCEANIC ISLANDS AS EVOLUTIONARY CENTERS

Data from exotic terranes have indicated that oceanic
islands were important centers of origin for higher taxa of
Bryozoa. Because of the highly deformed nature of rocks from
these sites, fossil bryozoans are often unidentifiable, or
identifiable only at higher taxonomic levels. Despite this,
island faunas have yielded a number of .first appearances of
bryozoan genera and higher taxonomic groups. Among them are:

1. The Treiorwerth Formation, of the Anglesey region of Southeast
Ireland, contains a Late Arenig bryozoan fauna consisting of
generalized trepostomes and the oldest phylloporinid (Neuman,
1984; Neuman and Bates, 1978).

8. A Late Arenig fauna from New World Island, Newfoundland
contains a number of unidentified trepostomes and the oldest
bifoliate cryptostome (Neuman, 1984; 1976).

3. The oldest fenestrate bryozoan, Alwxnopora orodamnus, was
described from the Late Arenig Tourmakeady Limestone of Nest
Ireland (Taylor and Curry, 1985).

4. A Late Ashgill fauna from the Portrane Limestone of Southwest
Ireland contains a fauna with the first recorded appearances
of the genera Discosgarsa, Hederella, and Icthyorachis (Ross,
1966b). Icthygggchig had previously been known from Devonian

age rocks, while Discosgarsa had been known from the

101

Cretaceous.

5. The oldest described trepostome, Drbigora §E., was reported
from the Lower Arenig Ogof Hen Formation of South Hales
(Taylor and Cope, 1987).

The first four of these localities were described by Neuman
(1984) as exotic terranes representing oceanic islands in the
Iapetus Ocean. Neuman found that oceanic island faunas contain
high percentages of endemic brachiopods, and cited the isolation,
topographic irregularities and lack of competition encountered by
pioneer species in these habitats as factors promoting endemism.
Hebby (1984b) noted that clathrodictyid stromatoporoids,
coenosteoid heliolitid corals and several groups of rugose
corals made their first appearances in island arc settings off

the coast of Australia.

DISCUSSION

One possible interpretation of these results is that there
may be a fundamental difference between speciation and the
evolution of higher taxa such as genera and families. Jablonski
and Bottjer (1983) suggested differences in speciation rates
between onshore and offshore species may be related to wider
geographic ranges and an increased frequency of planktotrophic
larval development among nearshore taxa. They further state that

because of their planktotrophic larval development, onshore taxa

102
are speciation and extinction resistant, but are more susceptible
to speciation events involving genetic transiliencies, which may
be sources of evolutionary novelty.

The mode of larval development for Ordovician Bryozoa is not
known. However, an attempt was made to compare geographic ranges
of nearshore vs. offshore genera, which might be correlated with
larval type. Geographic ranges of high speciation, offshore
localities (Southern Indiana, Southern Ohio, Northern Kentucky,
Central Tennessee, and Minnesota) and nearshore and reef centers
of evolution of higher taxa (Virginia, Oklahoma, Utah, Lake
Champlain and East Tennessee) are compared in Table 4.
Geographic range is estimated by the mean number of continents
occupied per genus from the Arenig through Caradoc, when
continents were still widely separated, 'and by per cent of
endemic genera (confined to one continent) in each fauna.

Except for Utah, the mean number of continents occupied
per genus is relatively constant for nearshore vs. offshore
localities. Genera from Utah are more widespread, with each genus
occupying an average of 4 continents, and no genera from Utah are
endemic. However, Utah has a diversity of only 6 genera which is
much lower than the generic diversities of other sites, which
range from 86-59. Thus the data from Utah may not be as reliable,
given the low sample size. Other nearshore and reef localities
have a high percentage of endemic genera. This reflects the fact
that many genera appeared at these sites and never migrated to

other continents or invaded the continental interior. Many rare

genera such as Amalgamogorous, Champlainogora, Chazydictxa,

103

Table 4. Endemicity of bryozoan genera.

Locality Mean number of continents % Endemic genera
occupied per genus per locality

1. Neagshore and reef:

 

Lake Champlain 8.9 88
Oklahoma 3.8 18
Utah 4.0 0
Virginia 8.8 86
East Tennessee 3.0 81
Mean .8 17.4
8. Offghgrg, intracratonic:

Central Tennessee 3.1 4
Northern Kentucky 8.9 13
Southern Indiana 3.0 18
Southern Ohio 3.0 10
Minnesota 8.9 18
Mean 3.0 10.8

104

Cricodictxum, Cystostictoporoug, Heminematogora,

Oeciophxlloporina, Tregostomina, Hemiulrichostylus, Ottoseetaxis,

 

Osburnostylus, Jordggopogg, and Lammotopora are confined to reef
or continental margin localities. Despite the high percentage of
endemics at these sites, the total faunal assemblages have the
same average generic ranges as the inner cratonic sites. This
indicates that the continental shelf and reef localities have a
mixed fauna, of cosmopolitan (planktotrophic?) and endemic
(nonplanktotrophic?) genera.

Nearshore environments are typically characterized as
unpredictable, high-stress, environments, with the implication
that environmental stress may somehow be related to evolutionary

innovation. In contrast, reefs are characterized as occupying

predictable, low-stress environments. Given the large
contribution of reefs and oceanic islands to evolutionary
innovation in the Bryozoa, perhaps the relationship of
environmental stress to evolutionary innovation has been

overestimated. Reefs and islands are spatially heterogeneous,
isolated environments. They offer the opportunity for species
assemblages of small population size to form, often isolated from
other reefs and islands by large distances. The occurrence of
these isolated units of small population size may be related to
the evolution of novel groups through the founder effect, the
spatially heterogenous nature of the environment and the lack of
selection pressure on pioneer species. Reefs often are found
associated with island arcs and may have provided early

colonization sites for newly evolved species.

105

Schopf (1977) viewed the evolution of new taxa as a process
of increasing specialization, whereby specialized forms arise
from generalized ancestors. Generalized taxa have life history
strategies most suited for unstable, nearshore environments.
Perhaps the reason higher taxa often appear in nearshore
environments is because only generalized forms have the
developmental plasticity necessary to allow evolutionary
innovation. Thus, the fact that this process occurs nearshore is
not because of any special evolutionary property of the nearshore
environment, but because the generalized, ancestral forms are
adapted to nearshore habitats.

Reef habitats are most suited for biotically competent,
specialized forms. Reefs were abundant in North America from the
Arenig through the Early Caradoc, but were rare from the Middle
Caradoc through the Middle Ashgill, possibly because of an
increase in terrigenous sedimentation from the Taconic Orogen and
because rising sea levels deposited widespread black shales over
the eastern midcontinent. They reappeared in the Late Ashgill in
the Hilliston Basin, Mellville Peninsula and Anticosti Island
areas of Canada; however, few novel groups appeared in reefs
after the Early Caradoc.

Gould (1977) outlined how two forms of paedomorphosis
(progenesis and neoteny) can act to preserve morphologic
generality in stable and unstable environments. Progenesis
(the acceleration of reproductive maturation) is a successful
adaptive strategy in unstable environments. Gould states that

when selection is focused on timing of reproductive maturity»

106

rather than on morphology, experimental morphologies can

develop because morphology is suddenly released from the

pressures of selection. Specialized adaptive strategies favor
delays in timing of reproductive maturity. In these
circumstances, juvenile features may be preserved in adult states
(neoteny), lending the organisms a certain evolutionary
plasticity. Anstey (1987) has documented several cases of

paedomorphic traits in nearshore Palebzoic bryozoans.
SUMMARY

1. The early radiation of the Bryozoa was largely concentrated
on the continent of Baltica, which was located in a temperate
climatic zone in the Southern Hemisphere.

8. Worldwide diversities and evolutionary rates greatly increased
in the Middle Ordovician, corresponding with a major eustatir
transgression.

3. Following the Late Ordovician mass extinction, Silurian
diversities and evolutionary rates were consistently lower
than in the Ordovician.

4. First appearances of bryozoan genera and families in North
America were largely concentrated in reefs and nearshore and
mid-shelf environments around the ancient continental margin.

5. Oceanic islands also were centers of origin for genera and
higher taxonomic groups of bryozoans and other marine
invertebrates.

6. First appearances of bryozoan species were largely

107

concentrated offshore, in the stable craton.

7. Differences in the onshore vs. offshore evolution of taxa
may be related to the presence of taxa with generalized
(and often paedomorphic) morphologies in nearshore areas,
and the spatial heterogeneity provided by the presence of

reefs on the continental shelf.

CHAPTER THREE

GRADIENT ANALYSIS AND BIOSTRATIGRAPHIC CORRELATION

108

109

INTRODUCTION

Gradient analysis has been used to quantify spatial
gradients in the distribution of taxa by ecologists and
paleoecologists. Cisne and Rabe (1978) used reciprocal averaging
to quantify spatial gradients in the distribution of fossils
along an onshore-offshore transect in the Ordovician of New York.
Anstey, Rabbio and Tuckey (1987a) used reciprocal averaging and
polar ordination to quantify spatial gradients in the
distribution of Late Ordovician bryozoan genera in North America
and to quantify stratigraphic gradients in the distribution of
bryozoan genera in a stratigraphic section in the Late Ordovician
of southern Indiana. These stratigraphic gradients were inferred
to represent bathymetric changes in the Late Ordovician epeiric
sea. Cisne, Gildner and Rabe (1984) also constructed bathymetric
curves for stratigraphic sections in New York and the upper
Mississippi Valley, using detrended correspondence analysis.
These sections were then correlated on the basis of synchronous
changes in sea level. The application of gradient analysis to
quantifying temporal gradients in the distribution of fossil
species and genera makes it a potentially useful tool in
biostratigraphy. Other multivariate techniques, such as cluster
analysis and nonmetric multidimensional scaling, have also been
used for quantitative stratigraphic correlations and construction

of assemblage zones. Descriptions of these techniques may be

110

found in Brower (1985), Hazel (1977) and Cubitt and Reyment
(1988).

Previous applications of gradient analysis have been high
resolution studies of the presence-absence or abundances of
taxa in measured stratigraphic sections. Changes in abundances
of taxa reflect paleoenvironmental changes associated with
transgressions and regressions. This approach differs from
previous studies in that the presence-absence of species in
formations spanning a long time interval (the Ordovican) is
analyzed. The limited stratigraphic range of species enables
gradient analysis to quantify an "age gradient" unrelated to
short term environmental changes.

To test the biostratigraphic utility of gradient analysis,
an analysis was done of the distribution of bryozoan species in
the Ordovician of Estonia. Estonia was chosen for this analysis
because it has a diverse bryozoan fauna and a complete sequence
of Ordovician formations ranging from Arenig through Ashgill in
age (Figure 43) exposed within a relatively small geographic
area, thus minimizing the potential for spatial variation. The
Balto-Scandian Ordovician formations lie in three major facies
zones. Each zone maintains its individuality and geographic
location throughout most of the Ordovician, and major faunal
changes between formations are usually not associated with a

change in lithology or facies (Jaanusson, 1976).

111

 

fif F2 Porkuni

ASHGILL % Flc Pirgu

g Flb Vormsi
535$? Fla Nabala

_ E Rakvere
D3 Oandu
DZ'Keila
D1 Johvi

 

CARADOC .

03 Idavere '

C2 Kuckers‘ '
LLANDEILO

C1 Tallin
_ UANVIRN

, B3 Kunda
ARENIG

'BZ Yolkhov

Figure 43. The Ordovician stratigraphic sequence of Estonia,

from Alikhova (1976) and Mannil (1966).

112

METHODS

Data on the distribution of bryozoans in the Ordovician of
Estonia were compiled from the publications of Bassler (1911),
Mannil (1959) and Modzalevskaya (1953). A data matrix was
compiled, listing the presence or absence of each species of the
bryozoan fauna in each formation of the Estonian Ordovician
sequence. This data matrix was used as input data for the
gradient analytic technique of detrended correspondence analysis,
(hereafter called DCA). DCA and reciprocal averaging are similar
to factor analysis in that they reduce the dimensionality of the
data matrix into a few major axes of variation. Sample scores are
ordinated with respect to their distance between the two poles,
or end points, of each axis. DCA and reciprocal averaging give
identical results on the first axis, but differ on subsequent
axes, as DCA axes are orthogonal, whereas subsequent axes of
reciprocal averaging are often correlated with the first axis.

A discussion of these gradient analytic techniques is provided in

Gauch (1988).

113

RESULTS

Ordination scores for the Ordovician formations of Estonia
are given in Table 5. DCA correctly ordinated the Estonian
formations with respect to age on the first axis, with the
exception of the B8 and 83 horizons which were juxtaposed, with
the 83 being classified as older than the B8. The juxtaposition
was probably due to the effect of two species, Diglotrxga
ggtropolitggg and Egrvohgllopogg bicornig, which were listed as
being present in the B8 horizon and abundant in the younger C
and D horizons, but were not recorded from the 83. This had the
effect of making the 88 appear more similar to formations of
younger age. These ordination results clearly indicate that

the first DCA axis serves as an “age" axis for Estonia.

A DATING OF THE ORDOVICIAN ERRATIC BOULDER FAUNA FROM POLAND

A bryozoan fauna from Ordovician erratic boulders from
Poland was described by Kiepura (1968). The fauna is known to be
Ordovician in age, however the precise age of the fauna has
never been determined. A dating of this fauna was attempted by
including the fauna from each boulder in the data matrix with the

Ordovician fauna of Estonia. Boulders containing fewer than 5

114

Table 5. First axis DCA ordination scores for the Ordovician
formations of Estonia

 

 

 

 

 

Eigenvalue = 0.819

 

 

Horizon DCA Score 0 of Genera # of Species
F8 683 80 88
Flc 538 18 81
Flb 581 87 34
Fla 508 17 19
E 879 85 38
03 195 47 73
D8 178 45 67
01 139 39 66
C3 130 34 . 56
C8 101 48 88
C1 58 31 49
B8 15 8 10

83 O 19 38

115

species were not included in the analysis. DCA ordination scores
for this analysis are listed in Table 6. The Estonian Ordovician
sequence is again ordinated with respect to age on the first
axis, with the exception of the B8 and 83 horizons and

the C8 and C3 horizons which are juxtaposed, although their
ordination scores are almost identical. Erratic boulders 0.804
from Mochty (province of Harsaw) and 0.17 from Uielki Kack
(province of Gdansk) are classified as being between the F1c
(Pirgu) and F8 (Porkini) horizons in age. Ordination scores for
the two boulders however, are closest to the F8 horizon, which is
Hirnantian (Latest Ashgill) in age. This evidence indicates that
these two erratic boulders from Poland are Hirnantian in age, and
are thus equivalent in age to the erratic boulders from the
Hirnantian of Ojlemyr, Gotland, whose fauna was described by
Spjeldnaes (1984). Schallreuter and Hillmer (1987) also noted the
similarity between the Ojlemyr fauna and the Polish boulder

fauna.

A DATING OF THE NAUNGKANGYI FORMATION OF BURMA

The fauna of the Naungkangyi formation of the North and
South Shan States of Burma was described in a series of papers by
Reed (1906, 1915, 1936). In the North Shan States, the
Naungkangyi is divisible into an upper member of predominantly

shales and a lower member of sandy marls, while in the South

116

Table 6. First axis DCA ordination scores for the Ordovician
formations of Estonia and erratic boulders 0.17 and 0.804
from Poland.

 

 

Eigenvalue = 0.881

 

Horizon DCA Score # of Genera # of Species
F8 659 80 88.
Boulder 0.17 688 10 14
Boulder 0.804 686 16 80
Flc 583 18 81
Flb 518 87 ' 34
Fla 494 17 19
E 307 85 38
D3 810 47 73
D8 805 45 67
01 150 39 66
C8 143 48 88
C3 140 34 56
Cl 83 31 49
88 80 8 10

B3 0 19 38

 

117

Shan the Naungkangyi exists as a series of shales and limestone
lenses and is not divisible into upper and lower units (Pascoe,
1959). The age of the Naungkangyi members has been estimated by
Pascoe to range from Llanvirn to Early Caradoc; however, Williams
(1973) included the Naungkangyi fauna in the Upper Caradoc, in
his cluster analysis of brachiopod faunas.

The Baltic affinities of the Naungkangyi fauna have been
recognized by Pascoe (1959), and in Chapter one of this thesis.
Because of the Baltic nature of the Naungkanyi fauna an attempt
was made to estimate the temporal position of the fauna by
including it in a DCA analysis with the Ordovician sequence of
Estonia. Since some of the Naungkangyi bryozoan fauna are
described only to the level of genus, the input data matrix
consisted of the presence or absence of bryozoan species and
genera in the Naungkanyi members and the Estonian formations.

First axis scores again show the Estonian sequence ordinated
by age (Table 7). The Upper and Lower Naungkangyi formations from
the North Shan and the Naungkangyi formation from the South Shan
all cluster in age between the E (Rakvere) and Fla (Nabala)
horizons of Estonia. Ordination scores for the South Shan
Naungkangyi and the North Shan Lower Naungkangyi are closest to
the ordination score for the E horizon of Estonia, while the
Upper Naungkangyi Formation clusters closest to the Fla horizon.
Alikhova (1976) placed the E horizon in the Upper Caradoc and the
Fla horizon in the Lower Ashgill. Thus, this analysis indicates

the Naungkangyi members to be of Late Caradoc to Early Ashgill

118

Table 7. First axis DCA ordination Ssores for the Ordovician
formations of Estonia and the Lower Naungkangyi (L-Naung) and
Upper Naungkangyi (U-Naung) Formations of the North Shan States
and the Naungkangyi (S-Naung) Formation of the South Shan States
of Burma.

 

 

 

 

Eigenvalue = 0.779

 

 

 

Horizon DCA Score 0 Genera # Species
F8 684 80 88
Flc 491 18 81
Flb 487 87 34
Fla 466 l7 l9
U-Naung 480 5 5
S-Naung 885 9 11
L-Naung 885 7 10
E 884 85 38
D3 813 47 73
D8 199 45 67
01 140 39 66
C3 138 34 56
C8 118 48 88
C1 67 31 49
B8 58 8 10

B3 0 19 38

 

 

 

119

age.

SUMMARY

Ordination analysis succesfully classified Estonian
formations of known age along an "age“ gradient on the first
DCA axis, with one exception. Hhen faunas of unknown age,
from the same biogeographic province, were included in the
analysis, the "age" gradient on the first axis remained intact
and the undated faunas were time correlated with Estonian
formations by their positions on the first axis. These results
indicate that gradient analysis is a useful biostratigraphic
tool because of its effectiveness in ordinating temporal
gradients, as well as an effective ecologic tool as ecologists
and paleoecologists have recognized.

This analysis also suggests that bryozoans are useful
tools in biostratigraphy. Despite the fact that paleontologists
such as E.O. Ulrich and R.S. Bassler recognized their
stratigraphic value, bryozoans have rarely been used in recent
biostratigraphic studies. Although species distributions are
often facies-controlled, the relatively short stratigraphic
ranges of many species make them useful for correlation within

biogeographic provinces or subprovinces.

CHAPTER FOUR

THE LATE ORDOVICIAN MASS EXTINCTION

120

121

INTRODUCTION

The Late Ordovician has been recognized as one of four
periods of Phanerozoic mass extinction, that significantly
exceed background extinction levels (Raup and Sepkoski, 1988).
Extinctions in this epoch affected a variety of marine
invertebrates including trilobites, echinoderms, graptolites,
conodonts and corals (Brenchly, 1984). The cause of the
extinctions has been attributed to climatic cooling associated
with the Late Ordovician glaciation, centered in North Africa
(Stanley, 1984), and to the marine regression associated with the
glaciation (Brenchly, 1984; Jaanusson, 1979). An analysis of the
terminal stratigraphic occurrences of Late Ordovician bryozoan
species and genera, drawn from a worldwide bryozoan data base,
indicates that the Late Ordovician extinction of bryozoans is a
composite of three discrete extinction events that significantly
exceed background extinction levels: a Late Caradoc event (Onnian
Stage) and two Late Ashgill events (Rawtheyian and Hirnantian
Stages, respectively). This paper seeks to demonstrate
differences in the fauna affected by each of these separate
events, and to propose extinction mechanisms consistent with

these differences.

122

ONNIAN EXTINCTIONS

A Poisson distribution test (Sepkoski and Raup, 1986) which
compares extinction maxima with local minima was applied to test
the significance of extinction peaks for bryozoan species and
genera during the Ordovician and Silurian (Figures 44 and 45). In
addition to a Middle Ordovician (Black River) event, these
extinction peaks rise above the 95% confidence limits: a Late
Caradoc peak, two Late Ashgill peaks and a Mid-Silurian peak.

The Late Caradoc extinction of bryozoan species totaled
over 50% of all Late Caradoc species recorded from the continents
of Baltica, Siberia and Southern Europe; however, only about 85%
of North American species were affected (Figure 46). Endemic
species and genera were significantly more prone to extinction
than cosmpolitan taxa, as taxa confined to one continent
suffered more than taxa on two or more continents (Figure 47).
Extinctions were concentrated among stenotopic species and
genera, as taxa confined to one lithotope suffered higher rates
of extinction than taxa occupying mixed lithologies (Figure 48).
Brenchly (1984) and Brenchly and Newell (1984) discussed Late
Caradoc extinction events for trilobites and brachiopods and
attributed them to a reduction in provinciality brought about by
plate movements reducing the width of the Iapetus Ocean. This
idea is supported by data on migrations of bryozoan genera, as

Baltica and Siberia, where extinctions were high, received larger

123

 

 

eao-o=-xm

 

 

 

 

 

 

Ago In Ma

Figure 44. Ordovician and Silurian extinctions of bryozoan genera
recorded in intervals of 4 million years. The dotted line
represents the 95% confidence intervals of a Poisson distribution
test which compares extinction maxima with local minima. Time
Scale is taken from stratigraphic charts of Ross et al. (1988).

124

 

 

“30"”03-exm

 

 

 

 

Ago In Ma

Figure 45. Ordovician and Silurian extinctions of bryozoan
Species, recorded in intervals of 4 million years. The dotted
line represents the 95% confidence intervals of a Poisson
distribution test. which compares extinction maxima with local
minima. Time scale is taken from stratigraphic charts of Ross

et al. (1988).

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numbers of migrants during the Late Caradoc, than North America,
where extinctions were low (Figures 8, 9 and 10). Spjeldnaes
(1981) described these migrations as the "Vaselemma" (Estonian E
Horizon) wave and characterized them as being marked by an
invasion of American trilobites, brachiopods and bryozoans into
Europe. Perhaps extinctions in Baltica and Siberia were related
to competition between migrants and stenotopic species which were

unable to expand their range to other lithotopes.

RAHTHEYAN EXTINCTIONS

Although the Late Ashgill extinction appears as a single
peak in Figures 44 and 45, it is a composite of two separate
extinctions, one during the Rawtheyan stage and one during the
Hirnantian (the final stage of the Ashgill). The stratigraphic
divisions of the Ashgill are shown in Figure 49. Rawtheyan
extinctions of bryozoa were concentrated in North America, where
approximately 90% of Late Ashgill species went extinct. Baltica
however, lost only about 5% of its species during the Rawtheyan
(Figure 50). Because stratigraphic data on bryozoan distributions
from Siberia, China and Southern Europe are imprecise, the effect
of the Rawtheyan and Hirnantian extinctions on these continents
cannot be determined. Rawtheyan extinctions were concentrated in
terrigenous and mixed terrigenous/carbonate lithotopes, as

opposed to those of pure carbonates (Figure 51). Extinctions

129

 

 

 

 

 

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et al. (1988).

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132
rates in terrigenous and mixed lithotopes exceeded 80% compared
to about 35% for carbonate lithotopes. Extinctions were highly
concentrated among species in the orders Trepostomata and

Tubuliporata.

HIRNANTIAN EXTINCTIONS

A second wave of Late Ashgill extinctions occurred during
the Hirnantian and the effects were quite different than those of
the Rawtheyan. Hirnantian extinctions were concentrated in
Baltica, which lost over 80% of its species, as opposed to North
America, which lost approximately 80% (Figure 50). Hirnantian
extinctions were concentrated in carbonate lithotopes as opposed
to terrigenous and mixed lithotopes, with rates exceeding 50% for
carbonates as opposed to approximately 10% for terrigenous and
mixed (Figure 51). Hirnantian extinctions were high among species
belonging to the orders Cryptostomata and Cystoporata.

The magnitude of the Hirnantian extinction was considerably
smaller than the Rawtheyan at the species level. The Hirnantian
extinctions also coincided with a large migratory wave of

North American genera into Baltica (Figure 9). Spjeldnaes (1981)
previously recognized this immigration as the ’Porkuni' (Estonian

F8 Horizon) wave.

133

DISCUSSION

Two major causes have been proposed for the Late Ordovician
mass extinction: global cooling (Stanley, 1984), and marine
regression (Brenchly 1984, and others). Stanley’s global cooling
hypothesis does not explain the differing effects of the
extinction on faunas from different lithotopes. Brenchly
attributed the first phase of the Late Ashgill extinctions to the
marine regression which decimated the shelf benthos via the
species-area effect. Jablonski (1985) questioned the role of the
species-area effect in extinctions by demonstrating the
importance of oceanic islands as refuges during marine
regressions. The shelf area around oceanic islands increases
during regressions. This analysis suggests that marine
regressions may cause extinctions by wiping out specific
types of habitats rather than through the species-area effect.

The Rawtheyan extinctions of bryozoan species were
concentrated in areas of terrigenous lithologies in North
America, while areas of carbonate lithologies were relatively
unaffected. Anstey (1986) found that over 50% of the genera in
the terrigenous Reedsville-Lorraine Biome and the mixed
terrigenous-clastic Cincinnati Biome did not survive into the
Silurian. This may be due to the fact that species from carbonate

environments were able to find similar habitats on the carbonate

134

shelves of oceanic islands, while species from terrigenous
environments had their habitat destroyed during the marine
regression. An oceanic island bryozoan fauna was described by
Ross (1966b) from the Portrane Limestone of Ireland. This fauna,
of Rawtheyan age, comes from an exotic terrane which was formerly
an island in the Iapetus Ocean (Neuman 1984) and has affinities
with North American and Baltic carbonate faunas. The
disproportionate effect of the Rawtheyan marine regression on
North American faunas is also evident in the brachiopods
(Sheehan 1975), as Baltica was apparently less affected by the
regression.

The presence of oceanic islands probably facilitated
faunal migrations, as the largely carbonate shelves of Baltica
received large numbers of immigrants during the Hirnantian.
Hirnantian extinctions may be related to a reduction in
provinciality associated with this migratory wave. Brenchly
(1984), however, attributed the Hirnantian extinctions to a rapid
rise in sea level at the end of the Hirnantian, which is
evidenced by deposits of Early Silurian black shale at many
Baltic localities. Sheehan (1987) associated this rapid rise in
sea level with the spread of anaerobic conditions in deep water
which led to the extinction of the Foliomena brachiopod
community. Raymond et al. (1987) also associated rising sea level
caused by glacial melting with increased equatorial seasonality
and high equatorial extinctions in Carboniferous brachiopods. The
Hirnantian migrations may, in turn, have been related to rising

sea level, as Hallam (1977) found that cosmopolitanism among

135

Jurassic bivalves increased during transgressions.

l.

8.

CONCLUSION

The Late Ordovician extinctions of bryozoa occurred in 3
discrete phases: A. An Onnian phase, B. a Rawtheyan phase,
and C. a Hirnantian phase.

Late Caradoc extinctions were concentrated on the continents
of Baltica, Siberia and Southern Europe and affected primarily
stenotopic and endemic species and genera. The Late Caradoc
was also a time of immigration of new genera onto Baltica and
Siberia.

Rawtheyan extinctions were concentrated among species
occupying terrigenous and mixed terrigenous/carbonate
lithotopes on North America.

Hirnantian extinctions were concentrated among species
occupying carbonate lithotopes on Baltica, and were
correlated with a wave of North American immigrants which
appear in Baltica at that time.

These data appear to be consistent with a hypothesis which
explains the Rawtheyan extinction through a destruction of
terrigenous habitats in North America by a marine regression
and the Hirnatian extinction through a reduction in
provinciality and low oxygen conditions associated with

the ensuing transgression.

B I BL I OGRAPHY

BIBLIOGRAPHY

Alikhova, T.N., 1976. Principle problems of the stratigraphy
of the Ordovician System: International Geology Revue.
18:898—904.

Amsden, T.N., 1974. Late Ordovician and Early Silurian
articulate brachiopods from Oklahoma, Southwestern Illinois
and Eastern Missouri. Okla. Geol. Surv. Bull. 119, 154 pp.

Anstey, R.L., 1986. Bryozoan provinces and patterns of generic
evolution and extinction in the Late Ordovician of North
America. Lethaia, 19:33-51.

Anstey, R.L., 1987. Astogeny and phylogeny: evolutionary
heterochrony in Paleozoic bryozoans. Paleobiology 13:80-43.

Anstey, R.L., Rabbio, S.F. and Tuckey, M.E.,1987a. Bryozoan
bathymetric gradients within a Late Ordovician Epeiric Sea.
Paleoceanography, 8:165-176.

Anstey, R.L., Rabbio, S.F. and Tuckey, M.E., 1987b. Major
community gradients and biome patterning on the Late
Ordovician epeiric sea in North America. Geol. Soc. Amer.
Abstr., 19:818.

Astrova, G.G.,1965. Morphologiya, istoriya razvitiya i
sistema Ordovikskiy i Siluriyskiy Mshanok. Akad. Nauk
SSSR Tr, Pal. Inst. T. 106.

Barnes, C.R., Norford, 8.8., and Skevington, D., 1981. The
Ordovician System in Canada. Int. Union Geol. Sci. Publ.
No. 8.

Bassler, R.S., 1911. The Early Paleozoic Bryozoa of the Baltic
Provinces: U.S. National Museum Bulletin, vol. 77, 388 pp.

Bergstrom, S.M., 1973. Ordovician Conodonts. In: Hallam, A.
(Ed.), Atlas of Palaeobiogeography. Elsevier, Amsterdam,
pp e “7.58 e

Berry, H.B.N.,1973. Silurian-Early Devonian Graptolites. In:
Hallam, A. (ed.), Atlas of Palaeobiogeography. Elsevier,
Amsterdam, pp.81-88.

Berry, H.B.N., 1979. Graptolite biogeography: A biogeography of
some Lower Paleozoic plankton. In: Gray,J. and Boucot, A.J.
(ed.), Historical Biogeography, Plate Tectonics and the
Changing Environment. Proc. 37th Ann. Biol. Coll., Oregon

_State Univ. Press, pp. 105-116.

136

137

Berry, U.B.N. and Boucot, A.J., 1970. Correlation of the North
American Silurian Rocks. Geol. Soc. Amer. Spec. Paper 108.

Boucot, A. J., 1979. Silurian. In: Robison, R.A. (ed.), Treatise
on Invertebrate Paleontology, Univ. Kansas, Pt. A,
pp. 167-188.

Boucot, A.J. and Johnson, J.G., 1973. Silurian brachiopods. In:
Hallam, A. (ed.), Atlas of Palaeobiogeography. Elsevier,
Amsterdam, pp. 59-66.

Brenchly, P.J., 1984. Late Ordovician extinctions and their
relationship to the Gondwana glaciation. In: Brenchly,
P.J., (ed.) Fossils and Climate, John Wiley and Sons, pp.
891-385.

Brenchly, P.J. and Newall, G., 1984. Late Ordovician
environmental changes and their effects on faunas. In:
Bruton, D.L. (ed.). Aspects of the Ordovician System,
Univ. of Oslo, pp. 65-80.

Brower, J.C., 1985. Multivariate analysis of assemblage zones.
In Gradstein, F.M., Agterberg, F.P., Brower, J.C. and
Schwarzacher, Quantitative Stratigraphy: Paris, UNESCO,
598 p.

Burrett, C., 1973. Ordovician biogeography and continental drift.
Palaeogeog., Palaeoclim.,Palaeoecol., 13:161-801.

Cisne, J.L. and Rabe, B.D., 1978. Coenocorrelation: Gradient
analysis of fossil communities and its applications in
stratigraphy, Lethaia, 11:341-364.

Cisne, J.L., Gildner, R.F. and Rabe, B.D., 1984, Epeiric
sedimentation and sea level: synthetic ecostratigraphy:
Lethaia 17:867-888.

Cocks, L.R.M. and McKerrow, U.S., 1973. Brachiopod distributions
and faunal provinces in the Silurian and Lower Devonian. In:
Hughes, N.F. (ed.), Organisms and Continents through Time.,
Spec. Pap. Palaeont. 18:891-304.

Cooper, M.R., 1977. Eustacy during the Cretaceous: Its
implications and importance. Palaeogeog. Palaeoclim.
Palaeoecol. 88:1-60.

Cramer, F.H. and Diaz, M.R., 1974. Early Paleozoic palynomorph
provinces and paleoclimate. In: Ross, C.A. (ed.),
Paleogeographic Provinces and Provinciality, SEPM Sp. Pub.
81, pp. 177—88.

Cubitt, J.M. and Reyment, R.A., 1988. Quantitative
Stratigraphic Correlation. New York, John Wiley and Sons,

138

301 p.

Darlington, P.J., 1957. Zoogeography. John Hiley and Sons,
New York.

Durazzi, J.T. and Stehli, F.G., 1978. Average generic age, the
planetary temperature gradient and pole location. Syst.
2001. 81:384-89. '

Elias, R.J., 1988. Late Ordovician solitary rugose corals of
Eastern North America. Bull. Amer. Paleontol. 81. 116 pp.

Ervin, C.P. and McGinnis, L.D., 1975. Reelfoot Rift: Reactivated
precursor to the Mississippi Embayment. Geol. Soc. Amer.
Bull. 86:1887-95.

Fichter, L.S. and Diecchio, 1986. The Taconic sequence in the
northern Shenandoah Valley, Virginia. In: Neathery, T.L.
(ed.), Southeastern Sect. Geol. Soc. Amer. Centennial
Field Guide, Vol. 6, pp. 73-83.

Fortey, R.A., 1984. Global earlier Ordovician transgressions
and regressions and their biological implications. In:
Bruton, D.L., (ed.), Aspects of the Ordovician System.
Univ. Oslo. pp. 37-50.

Frey, R.C., 1987. The occurrence of pelecypods in Early Paleozoic
eperic-sea environments, Late Ordovician of the Cincinnati,
Ohio area. Palaios 8:3-83.

Fritz, M.A., 1941. Baltic Ordovician fauna in Gaspe. Jour.
Paleont. 15:564.

Gauch, H.G., 1988. Multivariate Analysis in Community Ecology.
Cambridge Univ. Press, Cambridge.

Gould, S.J., 1977. Ontogeny and Phylogeny. Harvard Univ. Press,
Cambridge, Mass.

Gould, S.J. and Calloway, L.B., 1980. Clams and brachiopods-
ships that pass in the night. Paleobiol. 6:383-97.

Grubbs, D.M., 1939. Fauna of the Niagaran nodules of the Chicago
Area. Jour. Paleont. 13:543-560.

Hallam, A., 1977. Jurassic bivalve biogeography. Paleobiology,
3:58-73.

Ham, U.E., 1969. Regional geology of the Arbuckle Mountains,
Oklahoma. Okla. Geol. Surv. Guidebook l7.

Hazel, J.E., 1977. Use of certain multivariate and other
techniques in assemblage zonal biostratigraphy, examples
utilizing Cambrian, Cretaceous and Tertiary benthic

139

invertebrates. In: Kauffman, E.G. and Hazel, J.E. (eds.)
Concepts and Methods in Biostratigraphy. Stroudsburg, Pa.,
Dowden, Hutchinson & Ross, p. 187-818.

Hecht, A.D., and Agan, 8., 1978. Diversity and age relationships
in Recent and Miocene bivalves. Syst. 2001. 81:308-18.

Hickey, L.J., Nest, R.M., Dawson, M.R. and Choi, D.K., 1983.
Arctic terrestrial biota: Paleomagnetic evidence of age
disparity with mid-northern latitudes during the Late
Cretaceous and Early Tertiary. Science 881:1153-56.

Hintze, L.F., 1951. Lower Ordovician detailed stratigraphic
sections for Hestern Utah. Utah Geol. Min. Surv. Bull. 39.

Jaanusson, V., 1978. Aspects of carbonate sedimentation in the
Ordovician of Baltoscandia. Lethaia 6:11-34.

Jaanusson, V., 1973. Ordovician articulate brachiopods, In:
Hallam, A. (ed.), Atlas of Palaeobiogeography. Elsevier,
Amsterdam, pp. 19-85.

Jaanusson, V., 1976. Faunal dynamics in the Middle Ordovician
(Viruan) of Balto-Scandia. In: Bassett, M.G. (ed.) The
Ordovician System. Cardif, Hales, University of Hales.

Jaanuson, V., 1979. Ordovician. In; Robison, R.A., (ed.),
Treatise on Invertebrate Paleontology, Univ. of Kansas,
Pte A, ppm 136‘165.

Jablonski, D., 1980. Apparant versus real biotic effects of
transgressions and regressions. Paleobiol. 6:398-407.

Jablonski, D., 1985. Marine regressions and mass extinctions:
A test using the modern biota. In: Valentine, J.H. (ed.)
Phanerozoic Diversity Patterns Profiles in Macroevolution.
Princeton Univ. Press, Princeton, N.J., pp. 335-354.

Jablonski, D. and Bottjer, D.J., 1983. Soft bottom epifaunal
suspension-feeding assemblages in the Late Cretaceous:
Implications for the evolution of benthic paleocommunities.
In: Tevesz, M.J. and McCall, P.L. (ed.), Biotic Interactions
in Recent and Fossil Benthic Communites. Plenum Press, New
York, PP- 747-818.

Jablonski, D., Sepkoski, J,Jr., Bottjer, D.J., and Sheehan, P.M.,
1983. Onshore-offshore patterns in the evolution of
Phanerozoic shelf communities. Science 888:1183-85.

Jackson, J.B.C., 1974. Biogeographic consequences of eurytopy
and stenotopy among marine bivalves and their evolutionary
significance. Amer. Nat. 108:541-560.

Kaljo, D. and Klaaman, E., 1973. Ordovician and Silurian corals.

140

In: Hallam, A. (ed.), Atlas of Palaeobiogeography. Elsevier,
Amsterdam, pp. 37-46.

Kiepura, n.. 1968. Bryozoa from the Ordovician erratic boulders
of Poland. Acta Paleontologica Polonica 7:347-488.

Leggett, J.K., McKerrow, U.S., Cocks, L.R.M. and Rickards, R.B.,
1981. Periodicity in the Early Paleozoic marine realm. Jour.
Geol. Soc. Lond. 138:167-76.

Lindstrom, M., 1978. Ice-marked sand grains in the Lower
Ordovician of Sweden. Geol. Palaeont. 6:85.

Lindstrom, M., 1976. Conodont palaeogeography of the Ordovician.
In: Bassett, M.G., (ed.), The Ordovician System. Proc.
Palaeont. Ass. Symp., Univ. Hales Press, pp. 501-588.

Mannil, R.M., 1959. Voprosi stratigraphii i mshanki Ordovika
Estonii. Akad. Nauk Estonskoi SSR Otd. Tekn. Fiz.-Mat. Nauk.

Mannil, R.M., 1966. Istoriya Razvitiya Baltiyskogo Basseyna v
Ordovike. Eesti Teaduste Akad. Geol. Inst. Tallin, 800 p.

McKerrow, U.S., 1979. Ordovician and Silurian changes in sea
level. Jour. Geol. Soc. Lond. 136:137-145.

Mitchell, A.H., 1986. Ophiolite and associated rocks in four
settings: Relationship to subduction and collision.
Tectonophysics 185:869-85.

Modzalevskaya, E.A., 1953. Trepostomati Ordovika Pribaltiki i
ix stratigraficheskoe znachenie. Paleont. Sborn. VNIGRI 78:
91-167.

Nekhorosheva, L:V., 1976. Ordovician Bryozoa of the Soviet
Arctic. In: Bassett, M.G. (ed.), The Ordovician System.
Proc. Palaeont. Ass. Symp., Univ. Hales Press, pp. 575-88.

Neuman, R.B., 1976. Early Ordovician (Late Arenig) brachiopods
from Virgin Arm, New Horld Island, Newfoundland. Geol. Surv.

Neuman, R.B., 1984. Geology and paleobiology of islands in the
Ordovician Iapetus Ocean: Review and implications. Geol.
Soc. Amer. Bull. 95:1188-1801.

Neuman, R.B. and Bates, D.E.B., 1978. Reassessment of Arenig
and Llanvirn age (Early Ordovician) brachiopods from
Anglesey, North-Nest Hales. Paleont. 81:571-613.

Nur, A. and Ben-Avraham, 2., 1977. Lost Pacifica continent.
Nature 870:41-43.

Pascoe, E.H., 1959. A manual of the Geology of India and Burma

141
Vol. 8. Calcutta, Government of India.

Paul, C.R.C., 1976. Palaeogeography of primitive echinoderms in
the Ordovician. In: Bassett, M.G. (ed.), The Ordovician
System. Proc. Palaeont. Ass. Symp., Univ. Wales Press,
pp. 553-574.

Pestana, H.R., 1960. Fossils from the Johnson Spring Formation,
Middle Ordovician, Independence Quadrangle, California.
Jour. Paleont. 34:868-73.

Pitcher, M., 1964. Evolution of Chazyan (Ordovician) reefs of
Eastern United States and Canada. Bull. Can. Petr. Geol.
18:638-91.

Pojeta, J., 1979. Geographic distribution of Cambrian and
Ordovician rostroconch molluscs. In: Gray, J. and Boucot,
A.J., (ed.), Historical Biogeography, Plate Tectonics and
the Changing Environment. Proc. 37th Ann. Biol. Coll.
Oregon State Univ. Press, pp. 87-36.

Potter, A.W., Hotz, P.E., and Rohr, D.M., 1977. Stratigraphy and
inferred tectonic framework of Lower Paleozoic rocks in the
Eastern Klamath Mountains, Northern California. In: Stewart,
J.H., Stevens, C.H. and Fritsche, E.A. (ed.) Paleogeography
of the Western United States. Soc. Econ. Paleont. Mineral.
Symp. 1, PP- 481-40.

Raup, D. and Sepkoski, J.J.Jr., 1988. Mass extinction in the
marine fossil record. Science, 815:1501-1503.

Raymond, A.,1987. Paleogeographic distribution of Early
Devonian plant traits. Palaios, 8:113-38.

Raymond, A., Kelly, F.H. and Lutken, C.B., 1987. Mass extinction
and paleoclimate: The response of articulate brachiopods to
Carboniferous glacial onset. Geol. Soc. Amer. Abst. Prog.
19:813.

Read, J.F., 1980. Carbonate ramp-to-basin transitions and
foreland basin evolution, Middle Ordovician, Virginia
Appalachians. Amer. Ass. Petr. Geol. Bull. 64:1575-1618.

Reed, F.R.C., 1906. The Lower Paleozoic fossils of the Northern
Shan States, Burma. Paleotol. Ind. Vol. 8, No. 3.

Reed, F.R.C., 1915. Supplementary memoir on new Ordovician and
Silurian fossils from the Northern Shan States. Paleontol.
Inde VOIe 6’ N00 1e

Reed, F.R.C., 1936. The Lower Paleozoic faunas of the Southern

Rohr, D.M., 1979. Geographic distribution of the Ordovician

142

gastropod Maclurites. In: Gray, J. and Boucot, A.J., (ed.),
Historical Biogeography, Plate Tectonics and the Changing
Environment. Proc. 37th Ann. Biol. Coll., Oregon State Univ.
Press, pp. 45-58.

Rong, J.Y., 1984. Distribution of the Hirnantia fauna and its
meaning. In: Bruton, D.L., (ed.), Aspects of the Ordovician
System. Univ. Oslo, pp. 101-118.

Ross, J.R.P., 1966a. An Early Ordovician ect0proct from Oklahoma.
Okla. Geol. Notes 86:818-84.

Ross, J.R.P., 1966b. The fauna of the Portrane Limestone; IV,
Polyzoa. Brit. Mus. (Nat. Hist.) Bull. Geol. 18:109-35.

Ross, J.R.P., 1985. Biogeography of Ordovician ect0proct
(bryozoan) faunas. In: Nielsen, C. and Larwood, G.P., (ed.),
Bryozoa: Ordovician to Recent. Olsen and Olsen,

Fredensborg, Denmark, pp. 865-878.

Ross, R.J., 1976. Ordovician sedimentation in the western United
States. In: Bassett, M.G., (ed.), The Ordovician System.
Proc. Palaeont. Ass. Symp., Univ. Wales Press, pp. 73-106.

Ross, R.J., Adler, F.J., Amsden, T.W., Bergstrom, D., Bergstrom,
S.M., Carter, C., Churkin, M., Cressman, E.A., Derby, J.R.,
Dutro, J.T., Ethington, R.L., Finney, S.C., Fisher, D.W.,
Fisher, J.H., Harris, A.G., Hintze, L.F., Ketner, K.B.,
Kolata, D.L., Landing, E. Neuman, R.B., Sweet, W.C., Pojeta,
J,Jr., Potter, A.H., Rader, E-K-g REPEtSki’ J.E., Shaver,
R.H., Thompson, T.L., and Webers, G.F., 1988. The Ordovician
System in the United States. Int. Union Geol. Sci. Publ. No.
18.

Schallreuter, R. and Hillmer, G., 1987. Bryozoen aus
Ojlemyrflint-Geschieben von Sylt. In: Von Hacht, U. (ed.),
Fossilien von Sylt 8. Hamburg, Verlang, pp. 833-47. 0

Schopf, T.J.M., 1970. Taxonomic diversity gradients of ectoprocts
and bivalves and their geologic implications. Geol. Soc.
Amer. Bull. 81:3765-68.

Schopf, T.J.M., 1977. Patterns and themes of evolution among
the bryozoa. In: Hallam, A. (ed.), Patterns of Evolution
as Illustrated by the Fossil Record. Elsevier Publ. Co.
Amsterdam, pp. 159-807.

Schwalb, H.R., 1969. Paleozoic geology of the Jackson Purchase
region. Kentucky. Kent. Geol. Surv. Rept. Inv. 10, Ser. 10.

Scotese, C.R., 1986. Phanerozoic reconstructions: A new look at
the assembly of Asia. Univ. Texas Inst. for Geophysics Tech.
Repte N00 66’ 5‘. ppm

143

Scotese, C.R., Bambach, R.K., Barton, 0., Van Der Voo, R., and
Ziegler, A.M., 1979. Paleozoic base maps. Jour. Geol.,
87:817-877.

Sepkoski, J,Jr., 1981. A factor analytic description of the
Phanerozoic marine fossil record. Paleobiol. 7:36-53.

Sepkoski, J,Jr. and Miller, A.I., 1985. Evolutionary faunas and
the distribution of Paleozoic marine communities in space
and time. In: Valentine, J.W. (ed.), Phanerozoic Diversity
Patterns: Profiles in Macroevolution. Princeton Univ. Press,
Princeton New Jersey, pp. 153-190.

Sepkoski, J.J.Jr., and Raup, D., 1986. Periodicity in marine
extinction events. In: Elliott, D.K. (ed.), Dynamics of
Extinction, John Wiley & Sons, New York, pp. 3-36.

Sepkoski, J.Jr., and Sheehan, P.M., 1983. Diversification,
faunal change, and community replacement during the
Ordovician radiations. In: Tevesz, M.J. and McCall, P.L.
(ed.), Biotic Interactions in Recent and Fossil Benthic
Communities. Plenum Press, New York, pp. 673-717.

Sheehan, P.M., 1975. Brachiopod synecology in a time of crisis
(Late Ordovician-Early Silurian). Paleobiology, 1:805-818.

Sheehan, P.M., 1979. Swedish Late Ordovician marine benthic
assemblages and their bearing on brachiopod zoogeography.
In: Gray, J. and Boucot, A.J., (ed.), Historical
Biogeography, Plate Tectonics and the Changing Environment.
Proc. 37th Ann. Biol. Coll., Oregon State Univ. Press, pp.
61-73.

Sheehan, P.M., 1985. Reefs are not so different - They follow the
evolutionary pattern of level-bottom communities. Geol. 13:
46-49.

Sheehan, P.M., 1987. The Foliomena community--Life below the
thermocline in the Late Ordovician. Geol. Soc. Amer. Abst.

Prog., 19:845.

Skevington, D., 1973. Ordovician graptolites. In: Hallam, A.,
(ed.), Atlas of Palaeobiogeography. Elsevier, Amsterdam,
pp e 27-35 0

Spjeldnaes, N., 1981. Lower Paleozoic paleoclimatology. In:
Holland, C.H.,(ed.), Lower Paleozoic of the Middle East,
Eastern and Southern Africa, and Antarctica. John Wiley
and Sons, pp. 199-856.

Spjeldnaes, N., 1984. Upper Ordovician bryozoans from Ojl Myr,
Gotland, Sweden. Bull. Geol. Inst. Univ. Uppsala, N.S.
10:1-66.

144

Stanley, S.M., 1984. Temperature and biotic crises in the marine
realm. Geology, 18:805-808.

Stehli, F.G. and Wells, J.W., 1971. Diversity and age patterns in
hermatypic corals. Syst. 2001. 80:115-86.

Taylor, P.D. and Cope, J.C., 1987. A trepostome bryozoan from the
Lower Arenig of South Wales: Implications of the oldest
described bryozoan. Geol. Mag. 184:367-71. '

Taylor, P.D. and Curry, 8.8., 1985. The earliest known fenestrate
bryozoan, with a short review of Lower Ordovician Bryozoa.
Paleont. 88:147-58.

Vollmer, F.W., and Bosworth, W., 1984. Formation of melange in
a foreland basin overthrust setting: Example from the
Taconic Orogen. Geol. Soc. Amer. Spec. Paper 198, pp. 53-70.

Walker, K.R. and Ferrigno, K.F., 1973. Major Middle Ordovician
reef tract in East Tennessee. Amer. Jour. Sci. 873A:894-385.

Webby, B.D., 1980. Biogeography of Ordovician stromatoporoids.
Palaeogeog. Palaeoclim. Paleoecol. 38:1-19.

Webby, B.D., 1984a. Ordovician reefs and climate: a review. In:
Bruton, D.L., (ed.), Aspects of the Ordovician System.
Univ. Oslo Paleont. Conrt. No. 895, pp. 89-100.

Webby, B.D., 1984b. Early Phanerozoic distribution patterns of
some major groups of sessile organisms. Proc.'87th Int.
Geol. Congress, Vol. 8, pp. 193-808.

Whittington, H.B., 1966. Phylogeny and distribution of Ordovician
trilobites. Jour. Paleont., 40:696-737.

Whittington, H.B., 1973. Ordovician trilobites. In: Hallam, A.
(ed.), Atlas of Palaeobiogeography. Elsevier, Amsterdam,
pp. 13-18.

Whittington, H.B. and Hughes, C.P., 1978. Ordovician geography
and faunal provinces deduced from trilobite distribution.
Phil. Trans. Roy. Soc. Lond., 863:835-878.

Whittington, H.B. and Hughes, C.P., 1973. Ordovician trilobite
distribution and geography. In: Hughes, N.F., (ed.),
Organisms and Continents through Time. Spec. Pap. Palaeont.,
18:835-840.

Williams, A., 1973. Distribution of brachiopod assemblages in
relation to Ordovician palaeogeography. In: Hughes, N.F.,
(ed.), Organisms and Continents through Time. Spec. Pap.
Palaeont., 18:841-869.

Witzke, B.J., 1987. Models for circulation patterns in

ms

epicontinental seas applied to Paleozoic facies of North
America. Paleoceanography 2:829-48.

Witzke, B.J., Frest, T.J. and Strimple, H.L., 1979. Biogeography
of the Silurian-Lower Devonian echinoderms. In: Gray, J. and
Boucot, A.J., (ed.), Historical Biogeography, Plate
Tectonics and the Changing Environment. Proc. 37th Ann.
Biol. Coll., Oregon State Univ. Press, pp. 117-189.

Ziegler, A.M., Hansen, K.S., Johnson, M.E., Kelly, M.A., Scotese,
C.R., and Van Der Voo, R., 1977. Silurian continental
distributions, paleogeography, climatology and biogeography.
Tectonophysics, 40:13-51.

Ziegler, A.M., Bambach, R.K., Parrish, J.T., Barrett, S.F.,
Gierlowski, E.H., Parker, W.C., Raymond, A. and Sepkowski,
J.J.Jr., 1981. Paleozoic biogoegraphy and climatology. In:
Niklas, K.J., (ed.), Paleobotany, Paleoecology and Evolution
Praeger Publ., New York, New York, pp. 231—867.

Zinsmeister, W.J. and Feldman, R.M., 1984. Cenozoic high latitude
heterochroneity of Southern Hemisphere marine faunas.
Science 224:881-883.

APPEND I X A

APPENDIX A

DATA BASE BIBLIOGRAPHY

Agarwal, N.C., 1974. Discovery of bryozoan fossils in the
calcareous horizon of Garhwal Group, Pauri-Garhwal District,
UOP. Him. 6201. 43600—180

Allen, A.T. and Lester, J.G., 1954. Contributions to the
paleontology of Northwest Georgia. Geor. Geol. Surv. Bull.
68, 166 pps.

Allen, A.T. and Lester, J.G., 1957. Zonation of the Middle and
Upper Ordovician strata in Northwestern Georgia. Geor. Geol.
Surv. Bull. 66, 110 pps.

Alling, H.L., 1947. Diagenesis of the Clinton hematite ores
of New York. Geol. Soc. Amer. Bull. 58:991—1018.

Ami, H.M., 1898. Notes and descriptions of some new or hitherto
urecorded species of fossils from the Cambro-Silurian
(Ordovician) rocks of the Province of Quebec. Can. Rec. Sci.
5:96—103.

Ami, H.M., 1895. Notes on Canadian fossil Bryozoa. Can. Rec. Sci.
6:888-889.

Ami, H.M., 1896. Notes on some of the fossil organic remains
comprised in the geological formations and outliers of the
Ottawa Paleozoic Basin. Trans. Roy. Soc. Can. Vol. 8, Ser. 8,
Sect 4, pp. 151-58.

Ami, H.M., 1901. Preliminary list of fossil organic remains from
the Potsdam, Beekmantown (Calciferous), Chazy, Black River,
Trenton, Utica and Pleistocene formations comprised within
the Perth Sheet (No. 119) in Eastern Ontario. Can. Geol. Surv.
Ann. Rept. 14, Pt. F, pp. 80-89.

Amsden, T.W., 1957. Catalog of Middle and Upper Ordovician
Fossils. Okla. Geol. Surv. Circ. 43, 41 pps.

Anstey, R.L. and Perry, T.G., 1973. Eden Shale bryozoans: A
numerical study (Ordovician, Ohio Valley). Mich. St. Univ.
Mus., Vol. 1, No. 1, 80 pp.

Armstrong, H.S., 1945. Stigmatella in the Ordovician of the
Central Ontario Basin. Jour. Paleont. 19:149-57.

Astrova, 6.6., 1945. Nizhnesiluriskie Trepostomata Reki Kochima.
Vses. Paleont. Obshch. Ezheg., 18:81-98.

146

147

Astrova, G.G., 1951. Pervie nahodki Nizhnesiluriski Trepostomata
i Sibiri. Mosk. Obshch. Ispit. Prid., 1:188-135.

Astrova, G.G., 1955. O rodovix kompleksak mshanok v Silurski
otlozhenax Sovetskogo Souza. Bull. M.O.I.P. Otd. Geol. 30:
57-73.

Astrova, G.G., 1957. Nekotorie novie vidi mshanok iz Silura
Tuvi. Mater. Osnov. Paleont. (Akad. Nauk SSSR Paleont. Inst.)

Astrova, G.G., 1959. Verknesiluriskie mshanki Moldavi. Geol.
Sborn. Lvov. Geol. Obshch. 1:198-815.

Astrova, G.G., 1959. Siluriskie mshanki Tsentralnoi i Zapadnoi
Tuvi. Akad. Nauk SSSR, Paleont. Inst. Trudy, Tom 79, 74 pp.

Astrova, G.G., 1960. Siluriskie fistuliporidi iz severni rajonov
RSFSR. Sbornik Trudov Geol. Paleont., pp. 351-78.

Astrova, G.G., 1968. K voprosu o vozraste Siluriskiy otlozheniy
Podoli. Bull. Mosk. Obshch. Isput. Prir. 37:184-35.

Astrova, G.G., 1965. Morfologia, Istoria Razvita i Sistema
Ordovikski i Siluriski Mshanok. Tr. Paleont. Inst. Tom 56,
Izd. Nauka, 438 pp.

Astrova, G.G., 1970. Novie Siluriskie i Rannedevonski mshanki
Cystoporata i Trepostomata Estoniy i Podoliy. In: Astrova,
8.6. and Chudinova, I.I. (eds.) Novy Vidy Paleozoiskica
Mshonak i Korallov. Nauka, Moscow, pp. 7-87.

Astrova, G.G., 1973. Systematic position and scope of the
bryozoan genera Batostomella and Pseudobatostomella. Paleont.
Jour. 7:348-53.

Astrova, G.G., 1978. The History of Development, Systematics and
Phylogeny of the Bryozoa Order Trepostomata. Akad. Nauk SSSR.
Tr. Paleont. Inst., Tom 169.

Austin, G.M., 1987. Richmond faunal zones in Warren and Clinton
Counties, Ohio. U.S. Nat. Mus. Proc. 70:1—18.

Avrov, D.P. and Modzalevskaya, E.A., 1988. Pozdneordovikski
mshanki Ugo-Zapadnogo Altai. Ezheg. Vses. Paleont. Obshch.
85:80-97.

Bartley, J.W., 1980. Phenetic analysis of Fistuligora (bryozoa)
from the Henryhouse Formation (Silurian) of Southcentral
Oklahoma. Geol. Soc. Amer. Abst. Prog. 18:818-19.

Bassler, R.S., 1906. The bryozoan fauna of the Rochester Shale.
U.S. Geol. Surv. Bull. 898.

148

Bassler, R.S., 1906. A study of the James types of Ordovician
and Silurian Bryozoa. U.S. Nat. Mus. Proc. 30:1-66.

_/

Bassler, R.S., 1909. The cement resources of Virginia. Virg.
Geol. Surv. Bull. 8A, 309 pp.

Bassler, R.S., 1911. The Early Paleozoic bryozoa of the Baltic
Provinces. U.S. Nat. Mus. Bull. 77, 388 pps.

Bassler, R.S., 1911. Corynotryog, a new genus of tubuliporoid
Bryozoa. U.S. Nat. Mus. Proc. 39:497—587.

Bassler, R.S., 1915. Bibliographic index of American Ordovician
and Silurian fossils. U.S. Nat. Mus. Bull. 98.

Bassler, R.S., 1919. Molluscoidea. In: Systematic Paleontology.
Maryland Geol. Surv. Mem. Cambrian and Ordovician. pp.
818-830.

Bassler, R.S., 1983. Bryozoa. In: Systematic Paleontology.
Maryland Geol. Surv. Mem. Silurian. pp. 405-18.

Bassler, R.S., 1938. The stratigraphy of the Central Basin of
Tennessee. Tenn. Div. Geol. Bull. 38.

Bassler, R.S., 1935. Descriptions of Paleozoic fossils from the
Central Basin of Tennessee. Jour. Wash. Acad. Sci. 85:403-409.

Bassler, R.S., 1936. Nomenclatorial notes on fossil and recent
Bryozoa. Wash. Acad. Sci. Jour. 86:156-168.

Bassler, R.S., 1939. The Hederelloidea, a suborder of Paleozoic
cyclostomatous Bryozoa. U.S. Nat. Mus. Proc. 87:85-91.

Bassler, R.S., 1958. Taxonomic notes on genera of fossil and
recent bryozoa. Jour. Wash. Acad. Sci. 48:381-85.

Bassler, R.S., 1958. The structural features of the bryozoan
genus Homotryga, with descriptions of species from the
Cincinnatian Group. Proc. U.S. Nat. Mus. 86:565-98.

Bekker, H., 1919. New bryozoa from the Kuckers Stage in Esthonia.
Ann. Mag. Nat. Hist. 4:387-35.

Bekker, H., 1981. The Kuckers Stage of the Ordovician rocks
of NE. Estonia. Acta et Comm. Univ. Dorpatensis, A8, 1,
98 pps.

Bierbauer, 8., 1891. A check-list of the Paleozoic fossils of
Wisconsin, Minnesota, Iowa, Dakota and Nebraska. Minn. Acad.
Nat. Sci. Bull. 3:806-847.

Boardman, R.S., 1959. A revision of the Silurian bryozoan genus
15232392353. Smith. Misc. Coll. Vol. 139, No. 6, 14 pp.

149

Boardman, R.S., 1960. A revision of the Ordovician bryozoan

genera Batostoma, Anaphragma and Amplexogora. Smith. Misc.
Coll. Vol. 140, No. 5, 88 pp.

Boardman, R.S. and McKinney, F.K., 1976. Skeletal architecture
and preserved organs of four-sided zooids in convergent genera
of Paleozoic Trepostomata (Bryozoa). Jour. Paleont. 50:85—78.

Boardman, R.S. and Utgaard, J., 1966. A revision of the
Ordovician bryozoan genera Monticulipora, Perono ora,
Heterotryga, and Dekayia. Jour Paleont. 40:1088-1108.

Bolton, T.E., 1957. Silurian stratigraphy and paleontology of
the Niagaran escarpment in Ontario. Geol. Surv. Can. Mem. 889,

145 pp.

Bolton. T.E., 1966. Some Late Silurian Bryozoa from the Canadian
Arctic islands. Paleont. 9:517-88.

Bolton, T.E., 1966. Illustrations of Canadian fossils, Silurian
faunas of Ontario. Geol. Surv. Can. Pap. 66-5, 46 pp.

Bolton, T.E., 1977. Ordovician megafauna, Melville Peninsula,
Southeastern District of Franklin. Can. Geol. Surv. Bull.

269:23-39.

Bolton, T.E., 1986. Early Silurian Bryozoa from the Clemville
Formation of the Port Daniel region, Gaspesie Peninsula,
Quebec. Geol. Surv. Can. Curr. Res. Pap. 86-lB:97—106.

Bolton, T.E. and Ross, J.R.P., 1985. The cryptostomate bryozoan
Sceptropora (Rhabdomesina, Arthrostylidae) from Upper
Ordovician rocks of Southern Mackenzie Mountains, District
of Mackenzie. Geol. Surv. Can. Curr. Res. Pap. 85-1A:89-45.

Borg, F., 1965. A comparative and phyletic study on fossil
and recent bryozoa of the Suborders Cyclostomata and
Trepostomata. Ark. 2001. 8, (17), pp. 1—91.

Bork, K.B. and Perry, T.G., 1967. Bryozoa (ectoprocta) of
Champlainian age (Middle Ordovician) from Northwestern
Illinois and adjacent parts of Iowa and Wisconsin. Jour.
Paleont. 41:1365-98.

Bork, K.B. and Perry, T.G., 1968. Bryozoa (ectoprocta) of
Champlainian age (Middle Ordovician) from Northwestern
Illinois and adjacent parts of Iowa and Wisconsin. Part
8. Bythotrygg, Diplotrypg, Hemighragma, Heigrotrypa,
Stigmatella, Eridotrypg and Nicholsonella. Jour. Paleont.
48:337-55.

Bork, K.B. and Perry, T.G., 1968. Bryozoa (ectoprocta) of
Champlainian age (MIddle Ordovician) from Northwestern

150

Illinois and adjacent parts of Iowa and Wisconsin. Part 3.

Homotryga, Orbignyella, Prasogora, Monticulipogg, and
Cyphotrypg. Jour. Paleont. 48:1048-65.

 

Boulange, M.F., 1963. Sur quelques especies novelles de
bryozoaires de la Montagne-Noire. Soc. Geol. Fr. Bull.
Ser. 7, Vol. 5, No. 1, pps. 34-40.

Boulange, M.F. and Boyer, F., 1964. Sur l'age de la transgression
post Caledonienne dans le sud de la Montagne Noire. C.R. Acad.
Sci. Paris, 859:4309-18.

Bradley, J.H., 1985. Stratigraphy of the Kimmswick Limestone
of Missouri and Illinois. Jour. Geol. 33:49-74.

Bradley, J.H., 1930. Fauna of the Kimmswick Limestone of
Missouri and Illinois. Contr. Walker Mus. 8:819-90.

Branson, E.B., 1944. The Geology of Missouri. Univ. Missouri
Studies, Vol. 19, 535 pp.

Brenchly, P.J., and Cocks, L.R.M., 1988. Ecological associations
in a regressive sequence: The Latest Ordovician of the Oslo-
Asker District, Norway. Paleont. 85:783-815.

Bretsky, P.W., 1970. Upper Ordovician Ecology of the Central
Appalachians. Peabody Mus. Nat. Hist. Bull. 34.

Bretsky, P.W. and Bretsky, 3.8., 1975. Succession and repetition
of Late Ordovician fossil assemblages from the Nicolet River
Valley, Quebec. Paleobiology 1:885-37.

Brett, C.E. and Liddell, D.W., 1978. Preservation and paleo-
ecology of a Middle Ordovician hardground community.
Paleobiol. 4:389-48.

Brood, K., 1970. On two species of Saffordotaxis (Bryozoa)
from the Silurian of Gotland. Stockh. Contr. Geol. 81:57-68.

Brood, K., 1974. Paleoecology of Silurian Bryozoa from Gotland
(Sweden). In:8ryozoa, 1974. Proc. Third Int. Conf., Doc.
Labor. Geol. Fac. Sci. Lyon, Ser. 3. pps. 401-14.

Brood, K., 1974. Bryozoa from the Ludlovian of Bjarsjolagard
in Skane. Geol. Foren. Stockh. Foerh. 96:381-388.

Brood, K., 1974. Cyclostomatous Bryozoa from the Kullsberg
Limestone. Geol. Foren. Stockh. Foerh. 96:483-85.

Brood, K., 1975. Cyclostomatous Bryozoa from the Silurian of
Gotland. Stockh. Contr. Geol., Vol. 88, 119 pps.

Brood, K., 1978. Upper Ordovician Bryozoa from Dalmanitina beds
of Borenshult, Ostergotland, Sweden. Geol. et Paleont. 18:53-

151
78.

Brood, K., 1979. Bryozoans, In: Lower Wenlock Floral and Faunal
Dynamics; Vattenfallet Section, Gotland. Swed. Geol. Unders.
Ser. C. 73:178-80.

Brood, K., 1980. Bryozoa from the Upper Ordovician Dalmanitina
beds of Kinnekulle, Sweden. Geol. Foren. Stockh. Foerh.
108:87-35.

Brood, K., 1980. Hirnantian (Upper Ordovician) Bryozoa from
Baltoscandia. In: Larwood, G.P. and Nielsen, C. (ed.), Recent
and Fossil Bryozoa, 5th International Conference on Bryozoa,
Durham, 1980.

Brood, K., 1980. Late Ordovician Bryozoa from Ringerike, Norway.
Norsk. Geol. Tidsk. 60:161-73.

Brood, K., 1988. Ashgill Bryozoa from a fissure filling at
Solberga, Dalarna. Geol. Foren. Stockh. Foerh. 104:167-181.

Brood, K., 1988. Bryozoa from the Klingkalk at Jalltjarn in
Dalarna, Sweden. Stockh. Contr. Geol. 37:43-48.

Brown, B.D., 1965. Trepostomatous Bryozoa from the Logana and
Jessamine Limestones (Middle Ordovician) of the Kentucky
Bluegrass Region. Jour. Paleont. 39:974-1006.

Brown, G.D. and Daly, E.J., 1985. Trepostome bryozoa from the
Dillsboro Formation (Cincinnatian Series) of Southeastern
Indiana. Ind. Geol. Surv. Spec. Rept. 33, 95 pp.

Brown, J.C., 1948. Contributions to the geology of the
Province of Yunnan in Western China. The regional
relationships of the Ordovician faunas. Rec. Geol. Surv.
India 81:381-76.

Butts, C., 1915. Geology and mineral resources of Jefferson
County, Kentucky. Kent. Geol. Surv. Ser. 4, Vol. 3, Pt. 8,
pp. 1-870.

Butts, C., 1986. The Paleozoic Rocks. In: Adams, G.I. et al
Geology of Alabama. Alab. Geol. Surv. Spec. Rep. 14:41-830.

Butts, C., 1941. Geology of the Appalachian Valley in Virginia.
Virg. Geol. Surv. Bull. 58, 871 pps.

Butts, C., 1945. Hollidaysburg-Huntingdon folio, Pennsylvania.
U.S. Geol. Surv. 887, 80 pp.

Butts, C., 1948. Geology and mineral resources of the Paleozoic
area in Northwest Georgia. Georg. Geol. Surv. Bull. 54, 176

9135 -

152

Caley, J.F., 1936. The Ordovician of Manitoulin Island, Ontario.
Can. Dept. Mines Geol. Surv. Mem. 808:81-98.

Cavet, P., 1959. Le Paleozoique de la zone axiale des Pyrenees
Orientales Francaises. Bull. Serv. Carte Geol. Fr. Vol. 55,

No. 854, 816 pp.

Chadwick, G.H., 1944. Geology of the Catskill and Kaaterskill
Quadrangles. New York State Mus. Bull. 336, 851 pp.

Chamberlain, T.C., 1877. Lower Silurian. In: Geology of
Wisconsin. Vol. 8, 1873-77, Comm. Publ. Print., pp.
857-386.

Clark, T.H., 1919. A section in the Trenton Limestone at
Martinsburg, New York. Harv. Mus. Comp. 2001. Bull. 63:
1-19.

Claypole, E.W., 1883. On Helicopotg, a new spiral genus (with
three species) of North American fenestellids. Geol. Soc.
Lond. Quart. Jour. 39:30-38.

Collie, G.L., 1903. Ordovician section near Bellefonte,
Pennsylvania. Geol. Soc. Amer. Bull. 14:407-80.

Cooper, B.N., 1936. Stratigraphy and Structure of the Marion
Area, Virginia. Virg. Geol. Surv. Bull. 46:185-66.

Cooper, B.N., 1944. Geology and mineral resources of the Burkes
Garden Quadrangle, Virginia. Virg. Geol. Surv. Bull. 60, 899

pps-

Cooper, B.N., and Cooper, E.A., 1946. Lower Middle Ordovician
Stratigraphy of the Shenandoah Valley, Virginia. Geol. Soc.
Amer. Bull. 57:35-114.

Cooper, B.N. and Prouty, C.E., 1943. Stratigraphy of the Lower
Middle Ordovician of Tazewell County, Virginia. Geol. Soc.
Amer. Bull. 54:819-86.

Copeland, M.J. and Bolton, T.E., 1977. Additional paleontological
observations bearing on the age of the Lourdes Formation
(Ordovician), Port au Port Peninsula, Western Newfoundland.
Geol. Surv. Can. Paper 77-18, pp. 1-13.

Corneliussen, E.F. and Perry, T.G., 1973. Monotrypg, Hallo ora,
Amplgxopor§_and Henniqoporg (Ectoprocta) from the Brownsport
Formation (Niagaran), Western Tennessee. Jour. Paleont. 47:
151-880.

Coryell, H.N., 1915. A study of the collections from the Trenton
and Black River Formations of New York. Ind. Acad. Sci. Proc.
pp. 849-68.

153

Coryell, H.N., 1919. Bryozoan faunas of the Stones River Group
of Central Tennessee. Ind. Acad. Sci. Proc., pp. 861-340.
Crockford, J.M., 1941. Bryozoa from Silurian and Devonian of New

South Wales. Jour. Royal Soc. N.S.W. 75:104-114.

Crockford, J.M., 1943. An Ordovician bryozoan from Central
Australia. Proc. Linn. Soc. N.S.W. 68:148-49.

Culbertson, J.A., 1985. Fauna of the Brassfield Limestone of
Jefferson County, Indiana. Proc. Ind. Acad. Sci. 35:111-19.

Cullison, J.S., 1938. Dutchtown fauna of Southeastern Missouri.
Jour. Paleont. 18:819-88.

Cumings, E.R., 1908. The stratigraphy and paleontology of the
Ordovician rocks of Indiana. Ind. Dept. Geol. 38nd Ann. Rept.
pp. 739-886.

Cumings, E.R., 1989. Lists of species from the New Corydon,
Kokomo and Kenneth Formations of Indiana, and from reefs in
the Mississinewa and Liston Creek Formations. Proc. Ind.
Acad. Sci. 39:804-11.

Cumings, E.R. and Galloway, J.J., 1913. The stratigraphy and
paleontology of the Tanners Creek Section of the Cincinnatian
Series of Indiana. Ind. Dept. Geol. Ann. Rept. 37:353-478.

Dale, N.C., 1953. Geology and mineral resources of the Oriskany
Quadrangle. New York State Mus. Bull. 345.

Davidheiser, C.E., 1980. Bryozoans and bryozoan-like corals.
affinities and variability of Diplotrypg, Monotrypa,
Egbyrinthiteg, and Cladogora (Trepostomata and Tabulata)
from selected Ordovician-Silurian reefs in Eastern North
America (Newfoundland, Pennsylvania, Michigan). PhD Thesis,
Penn. State Univ.

Decker C.E. and Merritt, C.A., 1931. The stratigraphy and
physical characteristics of the Simpson Group. Okla. Geol.

Destombes, J., 1985. Lower Paleozoic rocks of Morocco. In:
Holland, C.H. (ed.), Lower Paleozoic of North-Western and
West Central Africa. John Wiley and Sons, Chichester, United
Kingdom, pp. 91-336.

Destombes, J, Termier, H. and Termier, G., 1971. Sur quelques
bryozoaires ectoproctes de L’Ordovicien Superieur du Sud
Marocain. Notes. Serv. Geol. Maroc. 837:61-64.

Doll, C.G., 1984. Fossils from the metamorphic rocks of the
Silurian-Devonian Magog belt in Northern Vermont. Verm.
Geol. 3:1-16.

154

Dowling, D.B., 1900. Report of the geology of the west shore
and islands of Lake Winnepeg. Can. Geol. Surv. Ann. Rept.
11F, 100 pp.

Dreyfuss, M., 1948. Contribution a l’etude geologique et
paleontologique de L’Ordovicien Superieur de la Montagne
Noire. Mem. Soc. Geol. Fr. No. 58, 63 pps.

Duncan, H., 1957. Bighornia, a new Ordovician coral genus.
Jour. Paleont. 31:607-15.

Dyer, W.S., 1985. The paleontology of the Credit River Section.
Ont. Dept. Mines 38nd Ann. Rept. 38:47-88.

Dyer, W.S., 1985. The stratigraphy and correlation of the
Credit River Section. Ont. Dept. Mines 38nd Ann. Rept. 38:
117-137.

Dzik, J., 1981. Evolutionary relationships of the Early
Paleozoic "Cyclostomatous“ bryozoa. Palaeont. 84:887-61.

Ehlers, G.M., 1983. The presence of Cataract strata in Michigan
supported by fossil evidence. Mich. Acad. Sci. Pap. 3:
881-83.

Ehlers, G.M., 1973. Stratigraphy of the Niagaran Series of the
northern peninsula of Michigan. Univ. Mich. Mus. Pap.
Paleont. No. 3, 800 pp.

Ehlers, G.M. and Kesling, R.V., 1957. Silurian rocks of the
northern peninsula of Michigan. Mich. Geol. Soc. Ann. Geol.
Exc., 63 pp.

Elias, M.K., 1956. A revision of Fenestella subantigua and
related Silurian fenestellids. Jour. Paleont. 30:314-38.

Ells, R.W., 1900. Report on the geology of the Three Rivers
Map-Sheet or northwestern sheet of the Eastern Townships
Map, Quebec. Can. Geol. Surv. Ann. Rept. 11J, 70 pp.

Erwin, R.B., 1957. The geology of the limestone of Isle
La Motte and South Hero Island Vermont. Vermont Geol. Surv.
Bull. 9, 94 pps.

Evans, 0.8., 1906. The Ordovician rocks of Western Caermarthen-
shire. Quart. Jour. Geol. Soc. Lond. 68:597-643.

Farmer, G.T., 1975. New bifoliate tubular bryozoan genera from
the Simpson Group (Middle Ordovician), Arbuckle Mountains,
Oklahoma. Bull. Amer. Paleont. 67:183-38.

Fenton, C.L., 1988. The stratigraphy and larger fossils of the
Plattin Formation in Ste. Genevieve County, Missouri. Amer.

155

Mid. Nat. 11:185-43.

Flugel, V.H., 1953. Die stratigraphischen verhaltnisse des
Palaozoiciums Von Graz. Neus. Jahrb. Geol. Pal. 8:55-98.

Foerste, A.F., 1877. The Clinton Group of Ohio. Part 3. Denison
Univ. Sci. Lab. Bull. 8:149-76.

Foerste, A.F., 1897. Geology of the Middle and Upper Silurian
rocks of Clark, Jefferson, Ripley, Jennings and Southern
Decatur Counties, Indiana. Ind. Dept. Geol. Nat. Res. 8lst
Ann. Rep. pps. 813-88.

Foerste, A.F., 1901. Silurian and Devonian limestones of
Tennessee and Kentucky. Geol. Soc. Amer. Bull. 18:395-444.

Foerste, A.F., 1904. The Ordovician-Silurian contact in the
Ripley Island area of Southern Indiana, with notes on the
age of the Cincinnati geanticline. Amer. Jour. Sci. 18:381-48.

Foerste, A.F., 1906. The Silurian, Devonian and Irvine Formations
of East-Central Kentucky. Kent. Geol. Surv. Bull. 7, 369 pp.

Foerste, A.F., 1916. Upper Ordovician formations in Ontario and
Quebec. Can. Dept. Mines Geol. Surv. Mem. 83.

Foerste, A.F., 1917. The Richmond faunas of Little Bay De
Noquette, in Northern Michigan. Ottawa Nat. 31:97-103, 181-
187.

Foerste, A.F., 1919. Silurian fossils from Ohio, with notes on
related species from other horizons. Ohio Jour. Sci. 19:367-
404.

Foerste, A.F.,.l980. The Kimmswick and Plattin Limestones of
Northeastern Missouri. Denison Univ. Sci. Lab. Bull. 19:
175-884.

Foerste, A.F., 1984. Upper Ordovician faunas of Ontario and
Quebec. Can. Dept. Mines Geol. Surv. Mem. 138.

Foerste, A.F., 1931. The Silurian fauna of Kentucky. In: The
Paleontology of Kentucky. Kent. Geol. Surv., Frankfort, Ky.

Foord, A.H., 1883. Descriptions of species: 1, On
Monticuliporidae of the Chazy, Black River and Trenton
Formations with descriptions of ten new species. Geol.
Surv. Can. Contr. Can. Micropal., Pt. 1, pp. 1-88.

Foord, A.H., 1883. On some previously unrecorded species of
Ptilodictyg, Stictoporg and Arthronema from the Trenton
Formation. Geol. Surv. Can. Contr. Can. Micropal., Pt. 1,
pp. 88-84.

156

Foord, A.H., 1884. On three species of monticuliporoid corals.
Ann. Mag. Nat. Hist. Ser. 5 Vol. 13, pp. 338-48.

Fritz, M.A., 1986. The stratigraphy and paleontology of the
Workmans Creek Section of the Cincinnatian Series of Ontario.
Roy. Soc. Can. Proc. Trans. 80:77-107.

Fritz, M.A., 1930. Two new species of fossils from the Paleozoic
rocks of Toronto. Trans. Roy. Can. Inst. 17:883-85.

Fritz, M.A., 1941. Baltic Ordovician fauna in Gaspe. Jour.
Paleont. 15:564.

Fritz, M.A., 1944. The Hull bryozoan Escharopora hogbeni. Jour.
Paleont. 18:863-64. .

Fritz, M.A., 1946. A Rhopalonaria in the Dundas Formation at
Toronto (Ontario). Jour. Paleont. 80:87.

Fritz, M.A., 1957. Bryozoa (mainly Trepostomata) from the
Ottawa Formation (Middle Ordovician) of the Ottawa- St.
Lawrence Lowland. Geol. Surv. Can. Bull. 48, 75 pp.

Fritz, M.A., 1965. Bryozoan fauna from the Middle Ordovician of
Mendoza, Argentina. Jour. Paleont. 39:141-48.

Fritz, M.A., 1966. Diplotrypg schucherti, a new bryozoan species
from the Long Point Formation (Ordovician), Western
Newfoundland. Jour. Paleont. 40:1335—37.

Fritz, M. A., 1970. Redescription of type specimens of the
bryozoan Hallogora from the Upper Ordovician of Toronto
region, Ontario. Geol. Ass. Can. Proc. 81:15-84.

Fritz, M.A., 1971. The trepostomatous bryozoan Stiqmgtellg
catenualta diversa Parks and Dyer (1988), a synonym for
Mesotrypg diversa (Parks and Dyer). Roy Ont. Mus. Life Sci.
Occ. Pap. 18, 6 pp.

Fritz, M.A., 1973. Redescription of type specimens of the
bryozoan Stigmatella from the Upper Ordovician rocks of
the Toronto region, Ontario. Roy. Ont. Mus. Life Sci.
Contr. B7, 31 pp.

Fritz, M.A., 1975. Redescription of type specimens of the
bryozoan Heterotryga from Upper Ordovician rocks of the
Credit River Valley, Ontario, Canada. Roy. Ont. Mus. Life
Sci. Contr. 101, 30 pp.

Fritz, M.A., 1976 redescription of type specimens of species
of the bryozoan genera Monticuliporg, Mesotryga, Peronopora
and Prasogora from the Upper Ordovician rocks of Toronto and
vicinity, Ontario, Canada. Roy. Ont. Mus. Life Sci. Contr.

157
107’ al. pp-

Fritz, M.A., 1977. Redescription of type specimens of species
of the bryozoan genera Atactoporella, Homotrypa and
Homotrygella from the Upper Ordovician rocks of the Credit
River Valley, Ontario, Canada. Roy. Ont. Mus. Life Sci.
Contr. 111, 84 pp.

Fritz, M.A., 1988. Redescription of type specimens of species
of the bryozoan genera Dekayia, Homotrypa and Stigmatella
from Upper Ordovician rocks along Workman’s Creek, Ontario.
Roy. Ont. Mus. Life Sci. Contr. 138, 38 pp.

Gardiner, C.I. and Reynolds, S.H., 1908. The fossiliferous
Silurian beds and associated igneous rocks of the Clogher Head
District (Co. Kerry). Quart. Jour. Geol. Soc. Lond. 58:886-66.

Gillette, T., 1947. The Clinton of Western and Central New York.
New York State Mus. Bull. 341, 191 pp.

Goldring, W., 1943. Geology of the Coxsackie Quadrangle, New
York. New York State Mus. Bull. 338.

Goryunova, R.V., 1975. The systematic position and content of the
genus Polyporellg. Paleont. Jour. 9:60-67.

Goryunova, R.V., 1980. A revision of the genus Nicklggoporg
(Bryozoa). Paleont. Jour. 14:78-80.

Grabau, A.W., 1901. Guide to the geology and paleontology of
Niagara Falls and vicinity. New York State Mus. Bull. 45:
161-76.

Grabau, A.W., 1906. Geology and paleontology of the
Schoharie Valey. New York State Mus. Bull. 98, 386 pp.

Grubbs, D.M., 1939. Fauna of the Niagaran nodules of the Chicago
area. Jour. Paleont. 13:543-60.

Gupta, V.J., 1967. Monotrypa sp. from the Upper Ordovician of
the Kashmir Himalayas. Res. Bull. (N.S.) Punjab Univ. 18:
505-06.

Gupta, V.J., 1969. Palaeozoic stratigraphy of the area southeast
of Sringar, Kashmir. Res. Bull. Punjab Univ. 80:1-14.

Gupta, V.J., 1969. Ordovician fossils from Gauran, Anantnag
District, Kashmir. Res. Bull. Punjab Univ. 80:547-553.

Gupta, V.J., 1973. Indian Paleozoic Stratigraphy. Hindustan Publ.
Co., Delhi, India, 807 pps.

Hall, J., 1847. Paleontology of New York, Volume 1. Albany,
C. Van Benthuysen.

158

Hall, J., 1858. Paleontology of New York, Volume 8. Albany,
’“C. Van Benthuysen.

Hall, J., 1888. Descriptions of the species of fossils found in
the Niagara Group at Waldron, Indiana. Ind. Dept. Geol. Nat.
.Res. 11th Ann. Rept., pp. 817-345.

Hall, J. and Whitfield, R.P., 1875. Descriptions of invertebrate
fossils, mainly from the Silurian System. Ohio Geol. Surv.
Rept. Vol. 8, Pt. 8 Paleontology, pp. 65-161.

Harkness, R., 1865. On the Lower Silurian rocks of the southeast
of Cumberland and the northeast of Westmoreland. Quart. Jour.
Geol. Soc. Lond. 81:835-49.

Harland, T.L., 1981. Middle Ordovician reefs of Norway.
Lethaia 14:169-188.

Havlicek, V. and Vanek, J., 1966. The biostratigraphy of the
Ordovician of Bohemia. Sborn. Geol. Ved. Paleontol. Rada 8:
7—5‘. a

Hennig, A., 1904. Gotlands Silur-Bryozoer, 1. Ark. 2001.
8; (10), pp. 1-37.

Hennig, A., 1905. Gotlands Silur-Bryozoer, 8. Ark. 2001.
3; (10), pp- 1-68.

Hennig, A., 1908. Gotlands Silur-Bryozoer, 3. Ark. 2001.
‘4; (81): PP. 1-64.

Heritsch, F., 1989. Faunen aus dem Silur der Ostalpen. Abh.
Geol. Bundesanst B. 83, H. 8, 183 pp.

Hewitt, M.C., 1988. Bryozoan reefs in the Middle Silurian
of New York and Ontario. Fistuliporoid bioherms on the
Irondequoit-Rochester boundary in Niagara Gorge. M.S.
Thesis, Penn. State Univ.

Hinds, R.W., 1970. Ordovician Bryozoa from the Pogonip Group of
Millard County, Western Utah. Brig. Young Univ. Geol. Stud.
17:19-40.

Hoar, F.G. and Bowen, Z.P., 1967. Brachiopoda and stratigraphy
of the Roundout Formation in the Rosendale Quadrangle,
Southeastern New York. Jour. Paleont. 41:1-36.

Hoffman, H.J., 1963. Ordovician Chazy Group in Southern Quebec.
Amer. Ass. Pet. Geol. Bull. 47:870-301.

Holtedahl, O., 1909. Studien uber die Etage 4 des Norwegischen
Silursystems beim Mjosen. Vid. Selsk. Skr. I, Mat. Nat. Kl.
No. 7, 48 pp.

159

Holtedahl, O., 1918. The Cambro-Ordovician beds of Bache
Peninsula and the neighbouring regions of Ellesmere Land.
In: Report of the Second Norwegian Arctic Expedition in
the "Fram" 1898-1908, No. 88, pp. 1-13.

Holtedahl, O., 1914. On the fossil faunas from Per Schei’s
Series B in South Western Ellesmereland. In: Report of the
Second Norwegian Arctic Expedition in the "Fram" 1898-1908,
No. 38, pp. 1-48.

Holzwasser, F., 1986. Geology of Newburgh and vicinity. New
York State Mus. Bull. 870, 95 pp.

Hu, Z.X., 1988. Silurian Bryozoa from Northern Sichuan and
Southern Shaanxi. Acta Pal. Sin. 81:890-301.

Hu, Z.X., 1986. Late Ordovician bryozoans from Yushan County,
Jianxi Province. Acta Pal. Sin. 3:167-183.

Hu, Z.X., Gong, L.Z., Yang, S.W. and Wang, H.D., 1983. New facts
concerning the Ordovician-Silurian boundary strata in Shiqian,
Guizhou. Jour. Strat. 7:140-48.

Hu, 2.x. and Wang, Y.F., 1986. Upper Silurian bryozoa from
Darhan Mumingan Joint Banner, Inner Mongolia.

Hussey, R.C., 1986. The Richmond Formation of Michigan. Univ.
Mich. Mus. Geol. Contr. 8:113-87.

Kaier, J., 1908. Das Obersilur im Kristianiagebiete. Vid.-
Selsk. Skr. I. Math.-Naturv. Kl. 596 pps.

Kaier, J., 1897. Faunistische uebersicht der Etage 5 des
Norwegischen Silursystems. Vid. Selsk. Skr. Mat. Nat. No.
3, 76 pp.

Karklins, D.L., 1969. The cryptostome Bryozoa from the Middle
Ordovician Decorah Shale, Minnesota. Minn. Geol. Surv. Spec.
Publ. 6, 181 pps.

Karklins, D.L., 1970. Restudy of the type species of the
Ordovician bryozoan genus Stictoporellina. Jour. Paleont.
44:133-39.

Karklins, D.L., 1978. Bryozoan fauna of the Upper Clays Ferry,
Kope, and Lower Fairview Formations (Edenian, Upper
'Ordovician) at Moffett Road, Northern Kentucky. U.S. Geol.
Surv. Open File Rep. 83-81, 56 pp.

Karklins, O.L., 1983. Ptilodictyoid Cryptostomata Bryozoa from
the Middle and Upper Ordovician rocks of Central Kentucky.
Paleont. Soc. Mem. 14, 31 pp.

 

160

Karklins, O.L., 1984. Trepostome and cystoporate bryozoans
from the Lexington Limestone and the Clays Ferry Formation
(Middle and Upper Ordovician) of Kentucky. U.S. Geol. Surv.
Prof. Pap. 1066-1, 105 pp.

Karklins, O.L., 1985. Bryozoans from the Murfreesboro and Pierce
Limestones (Early Black Riveran, Middle Ordovician), Stones
River Group of Central Tennessee. Paleont. Soc. Mem. 15, 48

pp-

Kay, G.M., 1989. Stratigraphy of the Decorah Fromation. Jour.
Geol. 37:639-71.

Kay, G.M., 1944. Distribution of Escharoporg hoqbeni Fritz.
Jour. Paleont. 18:560-61.

Kay, G.M., 1944. Middle Ordovician of Central Pennsylvania.
Jour. Geol. 58:1-83. ‘

Kay, G.M., 1953. Geology of the Utica Quadrangle, New York.
New York State Mus. Bull. 347.

Kayser, E., 1985. Contribuciones a la paleontologia de la
Republica Argentina. Sobre fosiles primordiales e
Infrasilurianos. Acad. Nac. Ciencies (Cord.) Actas 8:897-338.

Kettner, R., 1913. Uber das neue vorkommen der Untersilurischen
bryozoen und anderer fossilien in der ziegelei Pernikara
bei Kosire. Ceska Akad. Ved. a Umeni Bull. Int. 18:161-88.

Kiepura, M., 1968. Bryozoa from the Ordovician erratic boulders
of Poland. Acta Paleont. Polonica 7:347-440.

King, P.B., 1940. Geology of the Marathon Region, Texas. U.S.
Geol. Surv. Prof. Pap. 187, 148 pp.

Kobluk, D.R., 1980. Upper Ordovician (Richmondian) cavity-
dwelling (coelobiontic) organisms from Southern Ontario.
Can. Jour. Earth Sci. 17:1616-87.

Kobluk, D.R., 1981. Cavity-dwelling biota in Middle Ordovician
(Chazy) bryozoan mounds from Quebec. Can. Jour. Earth Sci.
18:48-54.

Kobluk, D.R. and Nemcsok, S., 1988. The macroboring ichnofossil
Trypanites in colonies of the Middle Ordovician bryozoan
Prasopora; Population behaviour and reaction to environmental
influences. Can. Jour. Earth Sci. 19:679-88.

Koch, L., 1989. The geology of the south coast of Washington
Land. Medd. Gronland, Vol. 73, No.1, pp. 1-39.

Kopayevich, G.V., 1971. The genus Digloclema (Bryozoa) and its
members from the Silurian of Estonia. Paleont. Jour. 5:850-54.

 

161

Kopayevich, G.V., 1973. The genera Stictopora and Rhinidictya
of the family Rhinidictyidae (Bryozoa, Cryptostomata).
Paleont. Jour. 7:336-40.

Kopayevich, G.V., 1975. Siluriskie Mshanki Estonii i Podolii.
Trans. Paleont. Inst. Acad. Sci. USSR, Vol. 151.

Kopayevich, G.V., 1978. Forms of intraspecific variation in
Fistuliporg catena, n. sp. Paleont. Jour. 18:85-98.

Kopayevich, G.V., 1984. Atlas mshanok Ordovika, Silura i
Devona Mongolii. Sovm. Sovetsko-Mong. Paleont. Eksped. Tr.
Vol. 88.

Kopayevich, G.V. and Ulitina, L.M., 1977. Novye dannye o rugozach
i mshanok v Verknem Silure Gory Kizildzhar-Choksu (Severo
Zapadnaya Mongolia). In:Tatarinov, L.P. (ed.), Mongolskaya
Paleontologiskaya Ekspeditsiya Trudy Bespozvonochnyka
Paleozoya Mongoli, Vol. 5, pp. 49-68, Izd. Nauka, Moskow.

Lambe, L.M., 1896. Description of a supposed new genus of
Polyzoa from the Trenton Limestone at Ottawa. Can. Rec. Sci.
731—3.

Laverdiere, J.W., 1936. Sainte-Anne River Area Portneuf County.
Que. Bur. Mines Ann. Rept., pp. 87-49.

Lavrentyeva, V.D., 1975. A new bryozoan genus of the family
Phylloporinidae. Paleont. Jour. 9:555-57.

Lavrentyeva, V.D., 1979. Phyllporinina a new suborder of
Paleozoic Bryozoa. Paleont. Jour. 13:56-64.

Lewis, H.P., 1933. The genus Constellaria Dana in Britian. Ann.
Mag. Nat. Hist. Vol. 18, No. 78, pp. 591-95.

Liberty, B.A., 1969. Paleozoic geology of the Lake Simcoe area,
Ontario. Geol. Surv. Can. Mem. 355, 801 pp.

Liddell, W.D. and Brett, C.E., 1988. Skeletal overgrowths among
epizoans from the Silurian (Wenlockian) Waldron Shale.
Paleobiol. 8:67-78.

Liu, X.L., 1980. Bryozoa. In: Paleontological Atlas of Northeast
China (1) Paleozoic. Geol. Publ. House, Beijing, China.

Loebich, A.R., 1948. Bryozoa from the Ordovician Bromide
Formation, Oklahoma. Jour. Paleont. 16:413-36.

Mannil, R.M., 1958. Novie mshanki otrada Cryptostomata iz
Ordovika Estoniy. Izvest. Akad. Nauk Est. SSR. 4:330-47.

Mannil, R.M., 1959. Voprosi stratigrafii i mshanki Ordovika

162

Estoniy. Akad. Nauk Eston. SSR. Otd. Tex. Fiziko-Mat. Nauk

Martin, 6.8., 1960. A preliminary investigation of the Upper
Ordovician bryozoa of Northwestern Alabama. Gulf Coast Ass.

Martison, N.W., 1958. Petroleum possibilities of the James Bay
Lowland Area. Ont. Dept. Mines Ann. Rept. 61:1-58.

Maw, U.B., San, V.B. and Ross, J.R.P., 1976. The Ordovician
bryozoan (ectoproct) Diplotrypg from Central Burma. Geol. Mag.
113:515-18.

Manten, A.A., 1971. Silurian Reefs of Gotland. Elsevier,
London, Amsterdam, New York.

Marintsch, E.J., 1986. Middle Ordovician trepostome Bryozoa
from carbonate platform deposits of the Southern Appalachian
Hermitage Formation, East Central Tennessee. Unpublished
manuscript.

Mather, K.F., 1917. The Trenton fauna of Wolfe Island, Ontario.
Ottawa Nat. 31:33-40.

McEwan, E.D., 1980. The Ordovician of Madison, Indiana. Amer.
Jour. Sci. 50:154-58.

McFarlane, A.C., 1931. The Ordovician fauna of Kentucky. In:
The Paleontology of Kentucky. Kent. Geol. Surv., Frankfort,
Ky.

McFarlane, A.C., 193B. Stratigraphic relationships of the
Lexington, Perryville and Cynthiana (Trenton) rocks of
Central Kentucky. Geol. Soc. Amer. Bull. 49:989-996.

McFarlane, A.C. and Freeman, L.B., 1935. Rogers Gap and Fulton
Formations in Central Kentucky. Geol. Soc. Amer. Bull. 46:
1975-8006.

McGerrigle, H.W., 1938. Faunas of the limestone and shale
formations of the Simard Area. Que. Bur. Mines Ann. Rept.
pp. 73-81.

McKinney, F.K., 1971. Trepostomatous ectoprocta (Bryozoa) from
the Lower Chickamauga Group (Middle Ordovician), Wills Valley,
Alabama. Bull. Amer. Paleont. 60:195-337.

McLeod, J.D., 1978. The oldest bryozoans: New evidence from the
Early Ordovician. Science 800:771-73.

McNamara, K.J., 1978. Symbiosis between gastropods and bryozoans
in the Late Ordovician of Cumbria, England. Lethaia 11:85-40.

 

163

Merida, J.E. and Boardman, R.S., 1967. The use of Paleozoic
“Bryozoa from well cuttings. Jour. Paleont. 41:763-65.

Miller, C.E., 1979. A reconnaissance survey of bryozoan
distribution within the Keyser Limestone (Silurian-Devonian)
of Central Pennsylvania. PhD Thesis, Penn. State Univ.

Miller, T.G., 1968. Some Wenlockian fenestrate Bryozoa. Palaeont.
5:540-49.

Milne Edwards, H. and Haime, J., 1854. A Monograph of the British
Fossil Corals, Part. 5, Paleontological Soc., London.

Monahan, J.W., 1931. Studies of the fauna of the Bertie
Formation. Amer. Midl. Nat. 18:377-96.

Modzalevskaya, E.A., 1953. Trepostomati Ordovika Pribaltika i ix
stratigraficheskoe znachenie. Paleont. Sborn. VNIGRI 78:
91-167.

Modzalevskaya, E.A., 1961. Mshanki Srednego Ordovika Basseina
R. Leni. Inform. Sb. VSEGEI, 47:51-73.

Modzalevskaya, E.A., 1968. Novie vidi Ordovikskikh i Siluriskich
trepostomat Tuvi. In: Novie Vidi Drevnik Rasteni i
Bespozvonochnykh SSSR, Vol. 8, No. 8, pp. 55-68.

Modzalevskaya, E.A., 1968. Novie vidi Siluriskikh i Devonski
mshanok Sredni Azii. In: Novie Vidi Drevnikh Rasteni i
Bespozvonochnykh SSSR, Vol. 8, No. 8, pp. 47-54.

Modzalevskaya, E.A., 1978. Ordoviskie Ceramoporidi Tuvi. In:
Novie Vidi Drevnikh Rasteniy i Bespozvonochnykh SSSR., Akad.
Nauk SSSR., pp. 168-63.

Modzalevskaya, E.A., 1977. Novaya Podnesiluriskaya Hallogora
Zapadnoy Tuvi. Ezheg. Vses. Paleont. Obshch. 80:883-85.

Modzalevskaya, E.A., 1977. Mshanki Srednego i Pozdnego Ordovika
Ugo-Zapadnoy Tuvi. Ezheg. Vses. Paleont. Obshch. 80:49-89.

Modzalevskaya, E.A., 1977. Novie vidi Siluriski mshanok Tuvi.
In: Stukalina, G.A. (ed.), Novie Vidy Drevnikh Rasteniy i
Bespozvonochnyka SSSR., Vyp. 4, Izd. Nauka, Moscow, USSR.
pp. 89-91.

Modzalevskaya, E.A., 1978. Komplekski mshanok Chergakskoi Serii
Tuvi. Ezheg. Vses. Paleont. Obshch. 81:119-47.

Modzalevskaya, E.A., 1979. Nekotorie Siluriskie mshanki Tuvi.
Ezheg. Vses. Paleont. Obshch. 88:63-93.

Modzalevskaya, E.A., 1980. Dva novie Lioclema iz Silura Tuvi.
In: Abushik, A.F. (ed.), Novie Vidy Drevnikh Rasteniy i

164

Bespozvonochnyka SSSR., Vyp. 5, Izd,. Nauka, Moscow, USSR.,
pp. 45-90.

Modzalevskaya, E.A., 1980. Monticuliporidae i Dittoporidae
Ordovika Tuvi. Ezheg. Vses. Paleont. Obshch. 83:98-111.

Modzalevskaya, E.A., 1981. Komplekski Przhidolskiy mshanok
Pripolarnogo Urala i Gradi Chernisheva. Ezheg. Vses. Paleont.
Obshch. 84:143-59.

Modzalevskaya, E.A. and Nekhoroshev, B.P., 1955. Klass Bryozoa-
Mshanki. In: Nikiforova, O.I. (ed.) Itolevoy Atlas Ordovikskoy
i Siluriskoy Fauni Sibirskoi Platformi. Vses. Nauchno-Issled.
Geol. Inst. VSEG.

Morozova, I.P., 1974. Revision of the bryozoan genus Fenestella.
Paleont. Jour. 8:167-80.

Narbonne, G.M. and Dixon, O.A., 1984. Upper Silurian lithistid
sponge reefs on Somerset Island, Arctic Canada. Sedimentol.
31:85-50.

Nekhoroshev, V.P., 1930. On certain Paleozoic Bryozoa in the
British Museum (Natural History). Geol. Mag. 67:178-89.

Nekhoroshev, V.P., 1933. Upper Silurian Bryozoa from Eastern
Balkashland. Trans. United Geol. Prosp. Serv. USSR. Fasc. 338.

Nekhoroshev, V.P., 1936. O rode Loculiporg i nekotorie drugik
Verknesiluriskiy mshankak Karagandinskogo Rajona Vostochnogo
Kazakstana. Trans. Cent. Geol. Prosp, Inst. F5. 61, pp. 83-36.

Nekhoroshev, V.P., 1936. Nekotorie Nizhnesiluriskie mshanki
iz Karniskiy Alp. Trans. Cent. Geol. Prosp. Inst. F5. 61,
pp. 5-88.

Nekhoroshev, V.P., 1956. Klass Bryozoa. Novie Semeystva i rodi.
Materiali VSEGEI, Novaya Seria VIP. 18 Materiali Po Paleont.
Str 0 42-49 m

Nekhoroshev, V.P., 1961. Ordovikskie i Siluriyskie mshanki
Sibirskoy Platformi. Vses. Nauchno-Issled. Geol. Inst.,
Tom 41.

Nekhoroshev, V.P., 1978. Novaya Rannesiluriskaya Unitryga
Vostochnogo Kazakhstan. In: Novie Vidy Drevnich Rasteniy i
Bespozvonochnykh SSR., Akad. Nauk SSSR., Moscow, USSR.
pp. 165-66.

Nekhorosheva, L. V., 1956. Mshanki Srednego Ordovika Uzhnogo
Ostrova Hoboi Zemli. Tr. NIIGA, T. 89, Sb. St. Po. Geol.
Arktiki, VIP. 6, pp. 78-80.

Nekhorosheva, L.V., 1966. Ordovikskie ptilodictyidi Taimir.

 

 

165

Nauchno-Issled. Inst. Geol. Arkt. Paleont.-Biostrat. 14:
22-37 0

Nekhorosheva, L.V., 1970. Ordovikski mshanki Severa Pay Koya,
Vaygach i Yuga Novoy Zemli. Nauchno Issled. Isnt. Geol.
Arkt., Leningrad, pp. 63-98.

Nekhorosheva, L.V., 1976. Ordovician Bryozoa of the Soviet
Arctic. In: Bassett, M.G. (ed.), The Ordovician System,
Univ. Wales Press, pp. 575-88.

Nekhorosheva, L.V., 1977. Ordoviskie mshanki Ostrova Kotelnogo.
In: Stratigrafia i Paleontologia Dokembria i Paleozoa Severna
Sibiri. Nauch-Issled. Inst. Geol. Arktiki, pp. 78-96.

Nekhorosheva, L.V., 1977. Novaya Sredneordovikskaya Diplotrypa
Ostrova Kotelnogo (Novosibirskie Ostrova). Ezheg. Vses.
Paleont. Obshch. 80:879-85.

Nekhorosheva, L.V., 1981. Pozdnesiluriskie i Rannedevonski
mshanki Ostrova Dolgogo. Ezheg. Vses. Paleont. Obshch. 84:

Neuman, R.B., 1964. Fossils in Ordovician tuffs Northeastern
Maine. U.S. Geol. Surv. Bull. 1181-E.

Nicholson, H.A., 1875. Descriptions of new species of Polyzoa
from the Lower and Upper Silurian rocks of North America.
Ann. Mag. Nat. Hist. Ser. 4 Vol. 15. pp. 177-84.

Nicholson, H.A., 1884. Contributions to micropaleontology.
Notes on some species of monticuliporoid corals from the
Upper Silurian rocks of Britian. Ann. Mag. Nat. Hist.
Ser. 5, Vol. 13, pp. 117-87.

Nicholson, H.A. and Etheridge, R., 1878. A monograph of the
Silurian Fossils of the Girvan District in Ayrshire. Fasc. 1,
William Blackwood and Sons, London, England.

Nickles, J.M., 1908. The geology of Cincinnati. Cin. Soc. Nat.
Hist. Jour. 80:49-100.

Nickles, J.M., 1908. Description of a new bryozoan "Homotrypa
bassleri” n. sp., from the Warren beds of the "Lorraine
Group“. Cin. Soc. Nat. Hist. Jour. 80: 103-105.

Nickles, J.M., 1906. The Upper Ordovician rocks of Kentucky and
their bryozoa. Kent. Geol. Surv. Bull. 5, 64 pp.

Nield, E.W., 1988. The earliest Gotland reefs: Two bioherms from
the Lower Visby beds (Upper Llandovery). Paleogeog. Paleoclim.
Paleoecol. 39:149-64.

Oakley, K.P., 1938. Some Ordovician bryozoa (Polyzoa) from

166

Akpatok Island. Ann. Mag. Nat. Hist. Ser. 11, Vol. 8, pp.

Oakley, K.P., 1966. Some pearl-bearing Ceramoporidae (Polyzoa).

Ockerman, J.W., 1986. Fauna of the Galena Limeston near Appleton.
Wis. Acad. Sci. Trans. 88:99-148.

Okulitch, V.J., 1935. Fauna of the Black River Group in the
vicinity of Montreal. Ottawa Nat. 49:96-107.

Okulitch, V.J., 1939. The Ordovician Section at Coboconk, '
Ontario. Trans. Roy. Can. Inst. 88:319-339.

Owen, D.E., 1960. Upper Silurian Bryozoa from Central.Wales.
Palaeont. 3:69-74. '

Owen, D.E., 1961. On the species Orbignyella fibrosa (Lonsdale).
Geol. Mag. 98:830-34.

Owen, D.E., 1968. Ludlovian Bryozoa from the Ludlow District.
Palaeont. 5:195-818.

Owen, D.E., 1965. Silurian polyzoa from Benthall Edge,
Shropshire. Bull. Brit. Mus. Nat. Hist. Geol. 10:95-117.

Owen, D.E., 1969. Wenlockian Bryozoa from Dudley, Niagara,
and Gotland and their palaeogeographic implications.
Paleont. 18:681-36.

Oxley, P. and Kay, M., 1959. Ordovician Chazyan Series of
Champlain Valley, New York and Vermont, and its reefs.
Amer. Ass. Pet. Geol. Bull. 43:817-53.

Ozaki, K., 1933. On two species of Ordovician Bryozoa from
South Manchuria. Jap. Jour. Geol. Geog.10:115-17.

Parks, W.A., 1915. Paleozoic fossils from a region southwest
of Hudson Bay. Trans. Roy. Can. Inst. 11:1-95.

Parks, W.A., 1983. The Stratigraphy and correlation of the
Dundas Formation. Ont. Dept. Mines 38nd Ann. Rep. pps.
89-116.

Parks, W.A., 1983. Addenda et corrigenda. Ont. Dept. Mines“
38nd Ann. Rep. pps. 35-38.

Parks, W.A., 1988. Faunas and stratigraphy of the Ordovician
black shales and related roCks in Southern Ontario. Trans.
Roy. Soc. Can. 88:39-98.

Parks, W.A. and Dyer, W.S., 1981. The stratigraphy and
paleontology of Toronto and vicinity. Part 8, The

 

167

Molluscoidea. Ont. Dept. Mines Ann. Rep., Vol. 30, Pt. 7,
58 pps.

Perry, T.G., 1968. Spechts Ferry (Middle Ordovician) bryozoans
fauna from Illinois, Wisconsin and Iowa. Ill. St. Geol. Surv.
Circ. 336, 36 pps.

Perry, T.G. and Hattin, D.E., 1958. Astogenetic study of
fistuliporoid bryozoans. Jour. Paleont. 38:1039-50.

Perry, T.G. and Hattin, D.E., 1960. Osgood (Niagaran) bryozoans
from the type area. Jour. Paleont. 34:695-710.

Pestana, H.R., 1960. Fossils from the Johnson Spring Formation,
Middle Ordovician, Independence Quadrangle, California.
Jour. Paleont. 34:868-73.

Phillips, J.R., 1960. Restudy of types of seven Ordovician
bifoliate Bryozoa. Paleontol. 3:1-85.

Pitcher, M., 1964. Evolution of Chazyan (Ordovician) reefs of
Eastern United States and Canada. Bull. Can. Petr. Geol.
18:638-91.

Pohowsky, R.A., 1978. The boring ctenostomate Bryozoa: Taxonomy
and paleobiology based on cavities in calcareous substrata.
Bull. Amer. Paleont., Vol. 73, No. 301.

Pouba, 2., 1947. A new bryozoan from the Bohdalec Shales
(Bohemian Caradoc). Mem. Soc. Sci. Boheme. 6:1-8.

Poulson, C.H.R., 1939. The Silurian faunas of North Greenland
1. The fauna of the Cape Schuchert Formation. Medd. Gronland
Vol 78, No. 1, pp. 1-46.

Poulson, C.H.R., 1941. The Silurian faunas of North Greenland
8. The fauna of the Offley Island Formation, Part 1
Coelenterata. Medd. Gronland Vol. 78, No. 8, pp. 1-87.

Prantl, F., 1938. On the genus Polyteichug Pocta. Vest. Kral.
Ceske Spol. Nauk, Tr. Mat. Prirod., Paper 18, pp. 1-14.

Prantl, F., 1939. Sur les bryozoaires Siluriens de la Montagne
Noire. C.R. Acad. Sci. Paris, 808:1415-16.

Prantl, F., 1939. Eine neue bryozoenart aus dem Bohmischen
Ordovizium. MItt. Tschech. Akad. Wiss. pps. 1-5.

Prantl, F., 1940. Some Ordovician and Silurian Bryozoa from
Montagne Noire (Languedock). Sborn. Nar. Mus. Praze. 83:
81-105.

Price, P.H., 1989. Pocahontas County. West Virg. Geol. Surv.
County Rept., 531 pp.

 

168

Price, F.H., 1939. Greenbriar County, West Virg. Geol. Surv.
”County Rept., 846 pp.

Prouty, W.F., 1986. Faunas of the Devonian, Silurian and
Ordovician Periods. In:Mercer, Monroe and Summers Counties.
West Virg. Geol. Surv. County Rept., pp. 860-67.

Pushkin, V.I., 1973. Hemieridotrypidae- A new family of Early
Paleozoic trepostomatous Bryozoa. Paleont. Jour. 7:484-98.

Pushkin, V.I., 1976. The genus Callocladia (Bryozoa) and its
new species from the Lower Paleozoic of Byelorussia. Paleont.
Jour. 10:60-66.

Pushkin, V.I., 1976. The genus Anaphragma (Bryozoa). Paleont.
Jour. 10:891-98.

Pushkin, V.I., 1977. A new Ordovician bryozoan genus. Paleont.
Jour. 11:453-59.

Pushkin, V.I., 1977. Brestopora novii rod mshanok Cyclostomata
iz Srednego Ordovika Bretskoi Vpadini. Paleont. Sborn. 14:
49-53.

Pushkin, V.I., 1980. Fatsialnaya zonalnost i braxiopodovo-
mshankovie assotsiatii Oanduskogo i Rakvereskogo gorizontov
Ordovika, Severnoi Belorussii. In: Ekostratigrafiya i
Ekologichesiye Sistemy Geologicheskogo Proshlogo. Trudy 88,
Sess. Vses. Paleont. pp. 80-30.

Raymond, P.E., 1903. The faunas of the Trenton at the type
section and at Newport, N.Y. Bull Amer. Pal. Vol. 4, No. 17,
18 pps.

Raymond, P.E., 1906. The Chazy Formation and its fauna. Ann.
Carn. Mus. 3:498-598.

Reed, F.R.C., 1906. The Lower Paleozoic fossils of the Northern
Shan States, Burma. Pal. Indica, Vol. 8, No. 3.

Reed, F.R.C., 1907. New fossils from Haverfordwest. Geol. Mag.
44:808-11.

Reed, F.R.C., 1910. Sedwick Museum notes. New fossils from the
Dufton Shales. Geol. Moag. 47:811-80.

Reed, F.R.C., 1918. Ordovician and Silurian fossils from the
Central Himalayas. Pal. Indica, Vol. 7, No. 8.

Reed, F.R.C., 1915. Supplementary memoir on new Ordovician and
Silurian fossils from the Northern Shan States. Pal. Indica,
Vol. 6, No. 1, 888 pps.

 

169

Reed, F.R.C., 1986. Some new Ordovician and Silurian fossils
from Girvan. Roy. Soc. Edinb. Trans. 54:735-39.

Reed, F.R.C., 1936. The Lower Paleozoic faunas of the Southern
Shan States. India Geol. Surv. Pal. Ind. Vol 81, No. 3.

Reed, F.R.C. and Reynolds, 1908. On the fossiliferous Silurian
rocks of the southern half of the Tortworth Inlier. Quart.
Jour. Geol. Soc. Lond. 64:518-45.

Reeds, C.A., 1911. The Hunton Formation of Oklahoma. Amer.
Jour. Sci. 188:856-68.

Reger, D.B., 1984. Mineral and Grant Counties. West Virg. Geol.
Surv. County Rept., 866 pp.

Rogers, W.S., 1960. Middle Ordovician stratigraphy of the Red
Mountain area, Alabama. Southeastern Geol. 8:817-49.

Rogers, W.S., 1961. The stratigraphic paleontology of the
Chickamauga Group of the Red Mountain area, Alabama.
Unpubl. PhD Diss., Univ. North Carolina.

Rohlich, P. and Chlupac, I. 1958. Svrchni Ordovik v byv.
reiserove cihelne u Reporyj. Ustred. Ustav. Geol. Sborn.

Rolfe, I. and Fritz, M.A., 1966. Recent evidence for the age of
the Hagshaw HIlls Silurian Inlier, Lanarkshire. Scot. Jour.
Geol. 8:159-64.

Ross, J.R.P., 1960. Larger Cryptostome Bryozoa of the Ordovician
and Silurian, Anticosti Island, Canada: (Part 1). Jour.
Paleont. 34:1057-76.

Ross, J.R.P., 1960. Re-evaluation of the type species of
Arthropor§_Ulrich. Jour. Paleont. 34:859-61.

Ross, J.R.P., 1961. Larger Cryptostome Bryozoa of the Ordovician
and Silurian, Anticosti Island, Canada: (Part 8). Jour.
Paleont. 35:331-44.

Ross. J.R.P., 1961. Ordovician, Silurian and Devonian Bryozoa of
Australia. Aust. Bur. Min. Res. Geol. Geophy. Bull. 50, 111

995-

Ross, J.R.P., 1968. Early species of the bryozoan genus
'EDQQQQQQLQ from the Caradoc Series, Shropshire. Palaeont. 5:
58-58.

Ross, J.R.P., 1968. Chazyan (Ordovician) Leptotrypellid and
Atactotoechid Bryozoa. Palaeont. 5:787-39.

Ross, J.R.P., 1963. New Ordovician species of Chazyan trepostome

170
and cryptostome Bryozoa. Jour. Paleont. 37:57—63.

Ross, J.R.P., 1963. Constellaria from the Chazyan (Ordovician)
Isle LaMotte, Vermont. Jour. Paleont. 37:51-56.

Ross, J.R.P., 1963. The bryozoan trepostome Batostoma in Chazyan
(Ordovician) strata. Jour. Paleont. 37:857-866.

Ross, J.R.P., 1963. Ordovician cryptostome Bryozoa, standard
Chazyan Series, New York and Vermont. Geol. Soc. Amer. Bull.
74:577-608.

Ross, J.R.P., 1963. Trepostome Bryozoa from the Caradoc Series,
Shropshire. Palaeont. 6:1-11.

Ross, J.R.P., 1964. Champlainian cryptostome Bryozoa from
New York State. Jour. Paleont. 38:1-38.

Ross, J.R.P., 1965. Homotrypa and Amplexopora? from the Caradoc
Series, Shropshire. Palaeont. 8:5-10.

 

Ross, J.R.P., 1966. The fauna of the Portrane Limestone, IV:
Polyzoa. Bull. Brit. Mus. (Nat. Hist.) Geol. 18:109-135.

Ross, J.R.P., 1966. Early Ordovician ectoproct from Oklahoma.

Ross, J.R.P., 1967. Champlainian Ectoprocta (Bryozoa), New York
State. Jour. Paleont. 41:638-48.

Ross, J.R.P., 1969. Champlainian (Ordovician) Ectoprocta
(Bryozoa), New York State, Part 8. Jour. Paleont. 43:857-84.

Ross, J. R. P., 1970. Distribution, paleoecology and correlation
of Champlainian EctOprocta (Bryozoa), New York State, Part
3. Jour. Paleont. 44: 346-88.

Ross, J.R.P., 1988. Middle and Upper Ordovician ectoproct
bryozoan faunas from the southwestern District of McKenzie,
Canada. Proc. Third N. Amer. Pal. Conv., Vol. 8:447-58.

Ross, R.J.R., 1957. Ordovician fossils from wells in the
Williston Basin, Eastern Montana. U.S. Geol. Surv. Bull.
1081-M: 99- 439-510.

Ross, R.J., Nolan, T.B. and Harris, A.G., 1979. The Upper
Ordovician and Silurian Hanson Creek Formation of Central
Nevada. U.S. Geol. Surv. Prof. Pap. 1186-0, pp. 1-88.

Roy, S.K., 1941. The Upper Ordovician fauna of Frobisher Bay,
Baffin Land. Field Mus. Nat. Hist. Geol. Mem. Vol. 8.

Rozman, X.S., Ivanova, V.A., Krasilova, I.N. and Modzalevskaya,
E.A., 1970. Biostratigrafia Verknego Ordovika Severo-Vostoka

171
SSSR. Trudy Geol. Inst. Leningrad, Vol. 805.

Ruddy, T., 1878. List of Caradoc or Bala fossils found in the
neighborhood of Bala, Corwen and Glyn Ceiriog. Proc. Chester
Soc. Nat. Sci. 8:113-184.

Ruedemann, R., 1901. Paleontologic papers 83 Trenton
conglomerate of Rysedorph Hill, Rensselaer Co., N.Y. and its
fauna. Rept. New York State Mus. 4:3-114.

Ruedemann, R., 1918. The Lower Siluric shales of the Mohawk
Valley. New York State Mus. Bull. 168, 151 pp.

Ruedemann, R., 1981. Report on fossils from the so-called Trenton
and Utica beds of Grand Isle, Vermont. Vermont St. Geol. Rep.
18:90-100.

Ruedemann, R., 1985. The Utica and Lorraine Formations of New
York: Part 8 Systematic Paleontology. New York State Mus.
Bull. 868.

Ruppel, S.C. and Walker, K.R.. Sedimentology and distinction of
carbonate buildups: Middle Ordovician, East Tennessee. Jour.
Sed. Pet. 58:1055-71.

Rusconi, C., 1956. Lista de los generos y especies fundadas por
Carlos Rusconi. Rev. Mus. Hist. Nat. Mendoza 9:181-56.

Sakagami, S., 1984. Outline of the Paleozoic Bryozoa in East
Asia. Geol. Pal. Soc. SE. Asia 85:173-181.

Salter, J.W., 1853. On Arctic Silurian fossils. Quart. Jour.
Geol. Soc. Lond. 9:318-17.

Savage, T.E., 1917. The Thebes Sandstone and Orchard Creek Shale
and their faunas in Illinois. Ill. Acad. Sci. Trans. 10:
861-75.

Savage, T.E., 1917. Stratigraphy and paleontology of the
Alexandrian Series in Illinois and Missouri, Part 1. 111.
Geol. Surv. Bull. 83:67-100.

Savage, T.E., 1984. Richmond rocks of Iowa and Illinois. Amer.
Jour. Sci. 8:411-87. ‘

Savage, T.E. and Van Tuyl, F.M., 1919. Geology and stratigraphy
of the area of Paleozoic rocks in the vicinity of Hudson and
James Bays. Geol. Soc. Amer. Bull. 30:339-78.

Schouppe, A., 1950. Archaeocyathacea in einer Caradoc-Fauna
der Grauwackenzone der Ostalpen. Neues Jahr. Geol. Pal. Abh.
Abt B 91:193-838.

Schuchert, C., 1900. On the Lower Silurian (Trenton) fauna of

172
Baffin Land. U.S. Nat. Mus. Proc. 88:143-78.

Secrist, M.H. and Evitt, W.R., 1943. The paleontology and
stratigraphy of the Upper Martinsburg Formation of
Massanutten Mountain, Virginia. Jour. Wash. Acad. Sci.
33:358-68.

Seely, H.M., 1906. Beekmantown and Chazy Formations in the
Champlain Valley, Contribution to their Geology and
Paleontology. Vermont St. Geol. Surv. Rep. 5:174-187.

Seigfried, P., 1963. Bryozoen in steinkernerhaltung aus
Ordovizischem geschiebe. Paleont. Z. 37 1/8:135-46.

Shaver, R.H., 1973. The Niagara (Middle Silurian) macrofauna
of Northern Indiana: review, appraisal, and inventory.
Ind. Acad. Sci. Proc. 83:301-15.

Sheinman, U.M., 1987. Mshanki Verknego Silura R. Sredni
Tunguski. Bull. Com. Geol. Leningr. 45:783-94.

Shimer, H.W., 1905. Upper Siluric and Lower Devonic faunas
of Trilobite Mountain, Orange County New York. New York
State Mus. Bull. 80:178-869.

Shishova, H.A., 1970. Nekotorie novie Siluriskie i Devonskie
mshanki Mongoli. In: Astrova, 6.6. and Chudinova, I.E.
(ed.), Novie Vidy Paleozoyskik Mshanok i Korallov. Akad. Nauk
SSR.

Shrock, R.R., and Raasch, 6.0., 1937. Paleontology of the
disturbed Ordovician rocks near Kentland, Indiana. Amer.
Mid. Nat. 18:538-607.

Shrock, R.R. and Twenhofel, W.H., 1939. Silurian fossils from
Northern Newfoundland. Jour. Paleont. 13:841-66.

Shrubsole, G.W., 1880. A review and description of the various
species of British Upper-Silurian Fenestellidae. Geol. Soc.
Lond. Quart. Jour. 36:841-54.

Shrubsole, G.W. and Vine, G.R., 1884. The Silurian species of
Glauconome and a suggested classification of the Paleozoic
Polyzoa. Quart. Jour. Geol. Soc. Lond. 40:389-38.

Simmons, G.C. and Oliver, W.A. Jr., 1967. Otter Creek coral
bed and its fauna, East-Central Kentucky. U.S. Geol. Surv.
Bull. 1844-F, 13 pp.

Sinclair, G.W., 1953. Middle Ordovician beds in Saguenay Valley,
Quebec. Amer. Jour. Sci. 851:841-54.

Singh, R.J., 1979. Trepostomatous bryozoan fauna from the
Bellevue Limestone, Upper Ordovician in the tri-state area

 

173

of Ohio, Indiana and Kentucky. Bull Amer. Paleont. Vol. 76,
No. 307, 888 pp.

Sissingh, W., 1965. Grote Paleozoische bryozoen uit het keileem.
Natuurh. Maandbl. 54:155-71.

Sparling, D.R., 1964. Prasoporg in a core from the Northville
area, Michigan. Jour. Paleont. 38:1078-81.

Spjeldnaes, N., 1957. A redescription of some type specimens of
British Ordovician bryozoans. Geol. Mag. 94:364—75.

Spjeldnaes, N., 1963. Some silicified Ordovician fossils from
South Wales. Palaeont. 6:854-63.

Spjeldnaes, N., 1984. Upper Ordovician bryozoans from Ojl Myr,
Gotland, Sweden. Bull. Geol. Inst. Univ. Uppsala, N.S. 10:
1-66.

 

Sproule, J.C., 1936. A study of the Cobourg Formation. Can. Geol.
Surv. Mem. 808:93-118.

Stauffer, C.R. and Theil, G.A., 1941. The Paleozoic and related
rocks of Southeastern Minnesota. Minn. Geol. Surv. Bull. 89,
861 pp.

Steele, H.M. and Sinclair, G.W., 1971. A Middle Ordovician fauna
from Braeside, Ottawa Valley, Ontario. Geol. Surv. Can. Bull.
811, 96 pps.

Stevens, N.C., 1958. Ordovician stratigraphy at Cliefden Caves,
near Mandurama, N.S.W. Proc. Linn. Soc. N.S.W. 77:114-80.

Stormer, L., 1953. The Middle Ordovician of the Oslo Region,
Norway: 1. Introduction to stratigraphy. Norsk. Geol. Tidsk.
31:37-141.

Stose, G.W., 1909. Mercersburg-Chambersburg Folio, Pennsylvania.
U.S. Geol. Surv. Folio No. 170.

Suyetenko, O.D., Sharikova, T.T. and Ulitina, L.M., 1977.
Stratigrafiya i fauna Paleozoya Vostochniy Otrogov Gobiskogo
Altaya (Mandalobinskim Massiv). In: Sovmestnaya Sovetsko-
Mongolskaya Paleontologiskaya Ekspeditsiya Trudy
Bespozvonochnyka Paleontologiskaya Mongoli, Vol. 5, pp. 38—48.

Taff, J.A., 1988. Preliminary report on the Geology of the
Arbuckle and Wichita Mountains in Indian Territory and
Oklahoma. Okla. Geol. Surv. Bull. 18, 95 pps.

Talent, J.A., 1965. The Silurian and Early Devonian faunas of
the Heathcote District, Victoria. Geol. Surv. Vict. Mem. 86,
55 pp.

174

Taylor, P.D. and Cope, J.C.W., 1987. A trepostome bryozoan fauna
from the Lower Arenig of South Wales: implications of the
oldest described bryozoan. Geol. Mag. 184:367-71.

Taylor, P.D. and Curry, 6.8., 1985. The earliest known fenestrate
bryozoan, with a short review of Lower Ordovician Bryozoa.
Paleont. 88:147-58.

Teichert, C., 1937. Ordovician and Silurian faunas from Arctic
Canada: 5th Thule expedition 1981-84. Rept. Vol. 1, No. 5,
169 pp. A.M.S. Press Inc, N.Y., N.Y.

Teller, E.E., 1911. A synopsis of the type specimens of fossils
from the Paleozoic formations of Wisconsin. Wis. Nat. Hist.
Soc. Bull. 9:170-871.

Termier, H. and Termier, G., 1948. Un biotope a bryozoaires
dans L’Ordovicien du Tafilelt (Maroc). Compte Rendu Soc.
BiogeOg. Paris 85:86-88.

Termier, G. and Termier, H., 1950. Paleontologie Marocaine
8. Invertebres de l'ere Primaire 8. Bryozoaires et
Brachiopodes. Notes. Mem. Serv. Geol. Maroc. 77:1-853.

Tilton, J.L., 1987. Hampshire and Hardy Counties. West Virg.
Geol. Surv. County Rept., 684 pp.

Toots, H., 1958. Bryozoen des Estnishen Kuckersits. Hamberg
Geol. Staatsinst., Mitt. H. 81:113-35.

Troedsen, J.C., 1950. Contributions to the geology of Northwest
Greenland, Ellesmere Island and Axel Heiberg Island. Medd. Om
Gron. Vol. 149, No. 7, 85 pp.

Twenhofel, W.H., 1914. Expedition to the Baltic Provinces of
Russia and Scandinavia, 1914 Part 8- The Silurian and high
Ordovician strata of Esthonia, Russia and their faunas.
Harv. Univ. Mus. Comp. 2001. Bull. 56:889-340.

Twenhofel, W.H., 1987. Ordovician strata in deep wells of
Western Central Kansas. Amer. Ass. Pet. Geol. Bull. 11:49-53.

Twenhofel, W.H., 1988. Geology of Anticosti Island. Can. Geol.
Surv. Mem. 154.

Twenhofel, W.H., 1938. Geology and paleontology of the Mingan
Islands, Quebec. Geol. Soc. Amer. Spec. Paper 11.

Ulitina, L.M., Bolshakova, L.N., Bondarenko, 0.8. and
Kopayevich, G.V., 1975. Stratigraficheskoe raspredelenie
stromatoporoidei, korallov i mshanok i Barunurtskom rajone
(Vostochnaya Mongolia). In: Kramerenko, N.(ed.), Sovmestnaya
Sovetsko-Mongolskaya Paleontologiskaya Ekspeditsiya, Trudy
Vol. 8, pp. 333-47.

 

17S

Ulitina, L.M., Bolshakova, L.N. and Kopayevich, G.V., 1976.
Osobennosti rasprostraneniya stromatoporoidea, rugoz i
mshanok v razreze Paleozoya Gori Dzhinsetu-Ula (Gobiski
Altai). In: Kramerenko, N. (ed.), Paleontologiya i
Biostratigrafiya Mongolii. Sovmestnaya Sovetsko-Mongolskaya
Paleontologiskaya Ekspeditsiya, Trudy Vol. 3, 387-40.

Ulrich, E.O., 1889. On some Polyzoa (Bryozoa) and Ostracoda
from the Cambro-Silurian rocks of Manitoba. Geol. Surv. Can.
Contr. Micropal. Part 8, pp. 87-57.

Ulrich, E.O., 1890. Paleozoic Bryozoa. Illinois Geol. Surv.
Vol. 8, Sect. 6, Geology and Paleontology, pp. 405-688.

Ulrich, E.O., 1895. On Lower Silurian Bryozoa of Minnesota.
Geol. Nat. Hist. Surv. Minn. Vol. 3, Pt. 1.

Ulrich, E.O. and Bassler, R.S., 1904. A revision of the Paleozoic
Bryozoa; Part 1- On genera and species of Ctenostomata. Smith.
Misc. Coll. 45:856—94.

Ulrich, E.O. and Bassler, R.S., 1904. A revision of the Paleozoic
Bryozoa; Part 8. Genera and species of the Trepostomata.
Smith. Misc. Coll. 47:15-55.

Ulrich, E.O. and Bassler, R.S., 1913. Class Bryozoa. In: Lower
Devonian. Maryland Geol. Surv.

Utgaard, J., 1968. A revision of North American genera of
ceramoporoid bryozoans (Ectoprocta): Part 1; Anolotichidae.
Jour. Paleont. 48:1033-41.

Utgaard, J., 1968. A revision of North American genera of
ceramoporoid bryozoans (Ectoprocta): Part 8; CreQiQora,

Ceramoporella, Acanthoceramoporella, and Ceramophylla.
Jour. Paleont. 48:1444-55.

Utgaard, J., 1969. A revision of North American genera of
ceramoporoid bryozoans (Ectoprocta): Part 3; The ceramoporoid
genera Ceramo ora, Pagillunaria, Favositella, and Haplotryga.
Jour. Paleont. 43:889-97.

Utgaard, J., 1981. Lunaferamita, a new genus of Constellariidae
(bryozoa) with strong cystoporate affinities. Jour. Paleont.
55:1058-70.

Utgaard, J. and Perry, T.G., 1964. Trepostomatous bryozoan fauna
of the upper part of the Whitewater Formation (Cincinnatian)
of Eastern Indiana and Western Ohio. Ind. Geol. Surv. Bull.
33, 111 pp.

Vascautanu, T., 1930. Formationile Siluriene din malvl Romanesc
a1 Nistrului. Ann. Rom. Inst. Geol. 15:485-584.

176

Vinassa de Regny, P., 1910. Fossili Ordoviciani del Nucleo
Centrale Carnico. Catamoa Atti Acc. Gioenia Ser. 5, Vol. 3,
Mem. 18, pp. 1-49.

Vinassa de Regny, P., 1914. Fossili Ordoviciani di Uggwa (Alpi
Carniche). Padova Mem. Inst. Geol. 8:195-881.

Vinassa de Regny, P., 1915. Ordoviciano e Neosilurico nei Gruppi
del Germula e di Lodin. Roma Boll. Com. Geol. It. 44:895-309.

Vinassa de Regny, P., 1915. Fossili Ordoviciani del Capolago
(Seekopf) presso il passo di Violaia (Alpi Carniche).
Pal. Ital. Pisa 81:97-115.

Vinassa de Regny, P., 1941. Fossili Ordoviciani Sardi, Parte 8.
Acc. Italia, Atti Cl. Sci. Mem. 18: 1085-55.

Vine, G.R., 1888. Notes on the polyzoa of the Wenlock Shales,
Wenlock Limestone, and shales over Wenlock Limestone. Quart.
Jour. Geol. Soc. Lind. 38:44-68.

Vine, G.R., 1885. Notes on species of Phyllopo:g_and Thamniscus
from the Lower Silurian rocks near Welshpool, Wales. Quart.
Jour. Geol. Soc. Lond. 41:108-13.

Vine, G.R., 1887. Notes on species of Ascodictxon and
Rhopalonaria from the Wenlock Shales. Ann. Mag. Nat. Hist.
Vol. 14, Ser. 5, pp. 77-89.

Vine, G.R., 1887. Notes on the Polyzoa of the Wenlock Shales,
etc. Part 1. Proc. Yorkshire Geol. Soc. 9:179-801.

Vladmirskaya, E.V., Vladmirskii, G.M. and Krivobodrova, A.V.,
1967. Sredne-Verkne Ordovikske otlozhenia Verkovev R.
Ak-Sug v Yugo-Zapadnoi chasti Zapadnogo Sayana. In:
Stratigrafiya i Paleogeografiya. Leningrad Gorn. Inst. Zap.
Vol. 53, No. 2, pp. 85-88.

Volkova, K.N., Latypov, Y.Y. and Khaisnikova, 1978. Ordovik
i Silur Uzhnogo Verkoania (Biostratigrafia i Paleontologia).
Trudy Inst. Geol. Geophy. Vol. 381 (Novosibirsk), 880 pp.

Waddington, J.B., 1980. A soft substrate community with
edrioasteroids, from the Verulam Formation (Middle Ordovician)
at Gamebridge, Ontario. Can. Jour. Earth Sci. 17:674-79.

Walker, K.R. and Ferrigno, K.F., 1973. Major Middle Ordovician
reef tract in East Tennessee. Amer. Jour. Sci. 873-A:894—385.

Walker, K.R., and Parker, W.C., 1976. Population structure of a
pioneer and a later stage species in an Ordovician ecological
succession. Paleobiol. 8:191-801.

177

Wass, R. and Dennis, D.M., 1977. Early Paleozoic faunas from the
Warwick-Stanthorpe region, Queensland. Search 8:807-08.

Welby, C., 1968. Paleontology of the Champlain Basin in Vermont.
Vermont Geol. Surv. Spec. Pub. 1, 88 pps.

Weissermel, W., 1939. Neue beitrage zur kenntnis der geologie,
paleontologie und petrographie der umgegund von
Konstantinopel: 3 Obersilurishe und Devonishe korallen,
stromatoporoides und trepostome, von der prinzeninsez
Antirovitha und aus Bithynien. Preuss. Geol. Landesanst.
Abh. 190, 131 pp.

White, I.C., 1916. Jefferson, Berkeley and Morgan Counties.
West Virg. Geol. Surv. County Rept., 644 pp.

White, I.C., 1987. Pendleton County. West Virg. Geol. Surv.
County Rept., 384 pp.

Whiteaves, J.F., 1895. Systematic list, with references, of the
fossils of the Hudson River or Cincinnati Formation at Stony
Mountain, Manitoba. Geol. Surv. Can. Paleoz. Foss. 3:111-88.

Whiteaves, J.F., 1897. Fossils of the Galena-Trenton and Black
River Formations of Lake Winnepeg and its vicinity. Geol.
Surv. Can. Paleoz. Foss. Vol. 3, Pt. 3.

Whiteaves, J.F., 1901. Preliminary list of fossils from the
Silurian (Upper Silurian) rocks of the Ekwan River, and
Sutton Mill Lakes, Keewatin, collected by D.B. Dowling
in 1901, with descriptions of such species as appear to be
new. Can. Geol. Surv. Ann. Rept. 14, Pt. F, pp. 38-59.

Whitfield, R.P., 1883. List of Wisconsin fossils. In: Geology of
Wisconsin, Vol. 1, 1873-79, Comm. Publ. Print, pp 368-75.

Williams, M.Y., 1919. The Silurian geology and faunas of Ontario
Peninsula, and Manitoulin and adjacent islands. Can. Dept.
Mines Geol. Surv. Mem. 111.

Wilson, A.E., 1981. The range of certain Lower Ordovician faunas
of the Ottawa Valley with descriptions of some new species.
Can. Geol. Surv. Mus. Bull. 33;19-57.

Wilson, A.E., 1931. Ordovician fossils from the region of
Cornwall, Ontario. Trans. Roy. Soc. Can. 86:373-408.

Wilson, A.E. and Mather, K.F., 1916. Appendix 8; Synopsis of the
common fossils in the Kingston area. In: Geology of Kingston
and Vicinity. Ont. Bur. Mines 85th Ann. Rept., pp.45-66.

Wilson, C.W., 1949. Pre-Chattanooga stratigraphy in Central
Tennessee. Tenn. Dept. Conserv. Div. Geol. Bull. 56, pp.
1-407.

 

178

Wolfart, R., 1970. Fauna, stratigraphie und paleogeographie
“'des Ordoviziums in Afghanistan. Beih. Geol. J8. Vol. 89,
169 pp.

Woodward, H.P., 1938. Geology and mineral resources of the
.Roanoke Area, Virginia. Virg. Geol. Surv. Bull. 34, 178 pps.

Yabe, H. and Hatasaka, I., 1980. Paleontology of Southern China.
Tokyo Geogr. Soc., Vol 3, 888 pp.

Yadrenkina, A.G., 1970. O Vozraste Dolborskogo gorizonta
Sibirskoi Platformi i granitse Srednego i Verknego Ordovika.
In: Materiali po Regionalnoi Geologii Sibiri. Sib. Nauchno-
Issled. Inst. Geol. Geof. Min. Tr. No. 110, pp. 116-181.

Yang, K.C., 1951. Two new species of Bryozoa from the Middle
Silurian of Kuangyuan, Szechuan. Geol. Soc. China Bull.
31:85-88.

 

Yang, K.C., 1957. Some Bryozoa from the upper part of the Lower
Ordovician of Liangshan, Southern Shensi (including a new
genus). Acta Pal. Sin. 5:7-88.

Yang, K.C. and Loo, L.H., 1968. Paleozoic Bryozoa of Qilianshan.
4 (5). Science Publ. House, Beijing, China, 118 pp.

Yang, K.C. and Xia, F. The Silurian bryozoans from Qujing of
Yunnan. Acta Pal. Sin. 15:41-54.

Yaroshinskaya, A.M., 1960. Mshanki. In: Khalfina, L.L. (ed.),
Biostratigrafia Paleozoa Sayano-Altaiskoi Gornoi Oblasti.
Tom 1, Nizhne Paleozoi, pp. 393-400.

Yaroshinskaya, A.M., 1968. Nekotorie predstaviteli mshanok
semestva Monticuliporidae iz Vernego Ordovika Gornogo Altai.
Tr. Sibirisk. Nauchno-Issled. Inst. Geol. Geofiz. 1 Mineral.
83:143-53.

Yaroshinskaya, A.M., 1967. Nekotorie novie mshanki iz Ordovika
Gornogo Altai Gornoi Shorii i Salaira. Sci. Not. Tomsk. St.

Yaroshinskaya, A.M., 1970. Nekotorie osobennosti geograficheskogo
rasprostranenia i ekologi Srednei Pozdeordovikski mshanok
zapadnoi chasti Altae Sayanskoi Gornoi Oblasti. Mosk. Obshch.
Ispyt. Prid. Byull. Otd. Geol. Mosk. 45:99-106.

Yaroshinskaya, A.M., 1973. Ordovician Bryozoa of the Altai-Sayan
region. In: Larwood, (ed.), Living and Fossil Bryozoans,
Academic Press, New York, pp. 481-88.

Yin, H.M. and Xia, F.G., 1986. Discovery of genus Batostoma
from the lower part of the Malieziken Group of Ruoqiang

 

179

Area, Xinjiang. Acta Micropaleont. Sin. 3:435-40.

Young, F.P.,-1943. Black River stratigraphy and faunas, Part 8.
Amer. Jour. Sci. 841:809-840.