QUANTIFICATION OF THE CEPHALOPOD SUTURE PATTERN By Douglas John Canfield A THESIS Submitted to Michigan State University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Department of Geology 1977 ABSTRACT QUANTIFICATION OF THE CEPHALOPOD SUTURE PATTERN By Douglas John Canfield The Fourier series exactly describes the shape of ceph- alopod suture patterns in the subclasses Nautiloidea, Bac- tritoidea, and in four of the eight orders of the Ammonoidea, but can not presently describe complex ammonitoid sutures. The Fourier method allows the calculation and graphical dis- play of the mean sutural patterns of the subclasses and orders studied, and exactly quantifies the morphological dif- ferences between groups. Discriminant analysis provides sig- nificant differentiation of the four ammonoid orders using only the Fourier harmonic amplitudes of the sutures. Discrim- inant analysis also reveals significant and otherwise undect- able differences between the two symmetric halves of sutures in Acanthoclymenia neapolitana, and thereby measures the non- genetic norm of recation in that species. Specific harmonic amplitudes increase monotonically in the ontobeny of Koenenites cooperi as well as in the phylogeny of four genera of the family Gephuroceratidae, with the result that the ontogenetic and phylogenetic scaling factors are statistically identical, confirming on a quantitative basis the assumption of recapi- tulatory evolution in this lineage. TABLE OF CONTENTS Acknowledgments . List of Tables. List of Figures Introduction. Methods Results Summary and Conclusions List of References. Appendix A . B . C D . E F Page ii iv 13 44 46 48 51 52 57 61 64 ACKNOWLEDGEMENTS I wish to thank Dr. Robert L. Anstey for his advice and guidance throughout this project. The helpful criticisms of Dr. Duncan Sibley and Dr. John Wilband are also greatly appreciated. Special thanks are given to Mitch Roth and Lloyd Lerew for their assistance with understanding mathe- matical, computational and philosophical problems. TABLE TABLE TABLE TABLE TABLE TABLE TABLE TABLE LIST OF TABLES Values of the Coefficient of Variation (CV) for six replications of Koenenites cogperi and seven replications of Goniatites choctawensis Mean values for the Coefficient of Variability computed for the taxonmic hierarchy. Summary of Discriminant Analysis of data from sutures in the Orders Anarcestinda, Clymeniida, Goniatitida, and Ceratitida. . . . . . Summary of Discriminate Analysis of data from Acanthoclymenia neapolitana. Perfect discrim~ ination between left and fight suture halves in both juvenile and adult sutures demonstrates presence of nongenetic influences on suture shape. Rankings of the harmonic amplitudes within each harmonic frequency for six suture patterns in the ontogenetic series of Koenenites cooperi The increase in rank sums withvage isia response to a general increase in signal with age Coefficient of Variation of the harmonic amplitudes, computed from the phylogentic series in the Family Gephuroceratidae and the onto- genetic series in Koenenites cooperi Significant Correlation Coefficients (R) of variables from the study of ontogeny in Koenenites cooperi. Significance level is a=.05 and a=.OI—suturavaariables are HARM l to HARM 20 and HZERO. Aperatural variables are AHARMl AHARM 20 and SIZE. Varimax rotated factor matrix after rotation with Kaiser normalization, computed from six sutures and aperature shapes in the ontogenetic series of Koenenites cooperi. AGE is the number of volutions of the conch, SIZE is the log of the mean radius of the aperature, HARM 1 through ii PAGE 14 15 23 24 28 32 TABLE 8 con't - HARM 20 are log transforms of sutural harmonic amplitudes, AHARM 1 through AHARM 20 are log transforms of aperatural Fourier harmonic amplitudes and HARMZERO is the zeroth harmonic amplitude of suture shape . . . . . . . . . . . . 37 TABLE 9: Significant Correlation Coefficients (R) of variables from the study of phylogeny in the Family Gephuroceratidae at a=. 05 and a=. Ol. SEQ is the log transform of the suture' 3 position in the phylogenetic series. HARM 1 through HARM 20 are log transforms of the Fourier harmonic amplitudes . . . . . . . . . . . . . . . 39 TABLE 10: Varimax rotated factor matrix after rotation with Kaiser normalization, computed form the four sutures representing a phylogeneitc series in the Family Gephuroceratidae. SEQ is the log of the suture's position in the series, HARM 1 through HARM 20 are log transforms of Fourier harmonic amplitudes, and HARMZERO is the zeroth harmonic amplitude. . . . . . . . . . . . . . . . 40 iii FIGURE FIGURE FIGURE FIGURE . FIGURE FIGURE FIGURE FIGURE FIGURE FIGURE 10: LIST OF FIGURES Variation in results, due to methods in six replications on the suture of Koenenites cooperi . . . . . . Variation in results, due to methods, in seven replications on the suture of Goniatites choctawensis Mean power spectra of Subclass Ammonoidea (A) and Subclass Nautiloidea (N). . Mean sutures of Subclasses Nautiloidea (A) and Ammonoidea (B) and a graphic display of the difference between them (C). . . . Power spectra of the mean suture patterns of Ammonoid Orders Anarcestida, Clymeniida, Goniatitida, and Cerititida . . . . . . Mean sutures of Orders Anarcestinda (A) and Clymeniida (B) and a graphic display of the difference between them (C) . . . Mean sutures of Orders Goniatitida (A) and Cerititida (B) and a graphic display of the difference between them (C) . Mean power spectra of left and right juvenile and adult sutures of Acanthoclymenia neapolitana . Power spectra of the ontogenetic series of sutures in Koenenites cooperi . Power spectra of the four sutres in the phylogenetic series in the Family Gephurocera- tidae. SEQ 1 = E, stainbrooki, SEQ 3 = M. sinuosum, SEQ 4 = K. cooperi, SEQ S = T EeyserIingi . . T . . . . . . . . iv PAGE 11 12 17 '18 19 20 21 25 27 29 FIGURE 11: FIGURE 12: FIGURE 13: PAGE Contributions of harmonic frequencies seven and eighteen to the fit of the approximations of Koenenites cooperi at 0.5 volutions (A), 5.5 volutions (B) and a graphic display of differ- ence between them,(C). . . . . 41 Relationship between the log transforms of harmonic amplitudes seven and eighteen in the ontogenetic series in E. cooperi . . . . . . . . 42 Relationship between the log transforms of harmonic amplitudes seven and eighteen in the phylogenetic series in the Family Gephuroceratidae . . . . . . . . . . . . . . . . 43 INTRODUCTION The importance of cephalopods in stratigraphy has long been recognized. The suture has been a primary character for the classification of these molluscs. In paleontology, cephalopod sutures have provided some of the classic examples of evolution by recapitulation and paedomorphosis (Tasch, p. 389, 1973). This study provides a preliminary evaluation of the use- fulness of Fourier analysis of suture patterns with respect to the higher taxonomy of the shelled cephalopods, their non- genetic norm of reaction, and their growth, development and phylogenesis. In his discussion of leaf outlines, D'Arcy Thompson (1917) used the metaphor of a Fourier series to explain var- iations in form as the superposition of sinusoidal closed form waves of varying period and amplitude upon one another. He implied that plant morphogenesis and phylogeny took place as Fourier analogs. The same point could possibley be made for the ammonoid suture in paleontology, which could represent the morphogenetic superposition of sinusoidal wave forms of different amplitude and harmonic order. Because biological growth and development commonly reflect natural periodic functions, the optimal curve-fitting and filtering of many biological forms will very likely be based on the Fourier series. Vicencio (1973) in an unpublished study attempted to use Fourier shape analysis to describe sutures. This was only a small aspect of a much larger study, and was incompletely developed. Fourier analysis has been successfully used to study the human face (Lu, 1965), the shapes of ostracodes (Younker, 1971; Kaesler and Waters, 1972; Ewald, 1975), pelecypods (Gevirtz, 1976), bryozoans (Delmet and Anstey, 1974; Anstey, Pachut and Prezbindowski, 1976), trilobites (Tuckey, 1975), blastoids (Waters, 1977), miospores (Chris- topher and Waters, 1974), and viruses (Crowther and Amos, 1971). The optimality of the Fourier basis of plane closed curve description has been demonstrated by Zahn and Roskies (1972). All of the above studies, with the exception of Vicencio, were based on nonsinusoidal closed forms (i.e. complete closed curves in polar coordinates). Ammonoid sutures are natural sinusoidal curves to which the application of the Fourier series should be particulary effective. Coefficients of variation (standard deviations divided by their means) are routinely used in biometry to compare the relative ariability of different measurements. Examina- tion of suture patterns from the widest possible taxonomic range makes it possible to calculate coefficients of variation of Fourier harmonic amplitudes at several heirarchical levels. It is then possible to compare quantitatively the degree of taxonomic variation in all of the Fourier wave forms filtered from the actual sutures. The Fourier series has the unique property of allowing the calculation of an exact mean suture pattern for any taxonomic group, or the construction of an exact intermediate suture pattern between any two "end mem- bers". The norm of reaction is a measure of the nongenetic, or ecophenotypic aspects of morphology. Because cephalopod sutures are bilaterally symmetrical about the mid-dorsum, available complete suture patterns provide estimations of the norm of reaction. The filtering capabilities of the Fourier series allow the subtraction of the asymmetry from the ob- served suture pattern, and the residual series can be used to reconstruct a more ”ideal" suture pattern than that actually produced by nature. Heterochrony implies that phylogenetic differentiation took place by extension or reduction of the development path- ways followed in ontogeny. The study of heterochrony in suture patterns has previously been graphic rather than quan- titative, and direct measurement of scaling factors has not been possible. The amplitudes of some Fourier wave forms vary monotonically in both ontogenetic and phylogenetic se- quences. These amplitudes can be used to calculate scaling factors directly and to test the assumptions of heterochrony in the taxa studied. METHODS Suture shape can be estimated as Y being a fuction of X by a Fourier series. The general form of the Fourier equation is co co f(x) = C0 + Z CNCOSZnNX/T + 2: SNsinZnNX/T (1) N=1 N=1 where T equals the range of the approximation, or the period of f(x). CO can be found by integrating both sides of (l) to obtain: t + T c - UT 05 f d (2) 0- to (x) x Multiplying (l) by cosZnNX/T or sinZan/T and integrat- ing finds CN and SN respectively. to + T CN = 2/T t5 f(x) c032nNX/T dx (3) O to + T SN = 2/T 6; f(x) sinZnNX/T dx (4) O A set of data points (Xi, Yi) is approximated by a Fourier series by determing f(x) by linear interpolation over the data and solving for the Fourier coefficients in the for- mulas (2), (3), and (4). Thus, if the n data points are ordered such that X1uzmaauz... u H zozmc: a an. a.» «— FD J 4 32..."- 25...? a...“ .3. 2.2+ «Sum. 23.0. .53.? a ‘ +000.Ne . \_ \ \. J 1. S34... . x x \c/ _ 2, , 2- .L \I. as .\ ‘, Jog-u! , ,\ .58.... $8.? 3001114118 OINOHUUH 001 12 FIGURE 2: Variation in results, due to methods, in seven replications on the suture of Goniatites choctawensis. mwmtaz >uzwncm¢m uuzozmmz 12a S m. 2 Z a .. u n . 0 a J. x 0 .1 T 0 log... 5 2...... .0. a 25.. I... 8.” _ 2.3. .0. Ho 3 35.. .x. .j 25.. ..T \ 1 «23.0. Sana- . , $3.0. a foaa.m- .92.“- \/ / / +61? ,_ V //.r 63;..- \ / t c .. ,2 62.. T x.) . my \\./ . J. . /. .lfifl . , . .. 1%... T / .\. .2. T .00... BOOIITJHU OINOHBUH 001 13 where n is the harmonic frequency number, 0 is the standard deviation and u is the mean. The graphs of the harmonic amplitudes vs. the harmonic frequency number (power spectra) of the six repitions of E; cooperi (Figure 1) show a large variation of the harmonic amplitudes at harmonic frequencies eleven and fourteen, The coefficient of variation has maxima of 66.64 and 69.83 at these respective frequencies (Table 1). The seven replica- tions of g. choctawnsis (Figure 2) and E. cooper (Figure l) is that relative variations increases greatly as the harmonic amplitude drops below 10-2. This threshold level can be lowered by reducing random noise due to methods. More accur- ate digitizing equipment (accuracy greater than .025 in.) or greater enlargment of suture patterns (larger than 8 X 10 photographs) can increase the signal strength with respect to noise. RESULTS A data set of 140 sutures was analyzed and the mean harm- onic amplitudes were calculated for the portion of the tax- onomic hierarchy sampled (Appendix D). In order to compare the degree of taxonomic variation in the Fourier was forms, the coefficients of variation (CVn) was also computed for taxonomically hiearchical levels (Appendix E). Table 2 gives the mean coefficients of variability within hierarchical levels. Harmonic frequency four shows a relatively constant CV, with a minimum of 38.21 and a maximum of 45.19. The second TABLE 1: Values of the Coefficient of Variation (CV) for six replications of Koenenites cgpperi and seven replications of Goniatites choctawensis. HARMONIC FREQUENCY COEFFICIENT 0F VARIATION K. cooperi g. choctawensis l 2.46 4.51 2 2.78 4.53 3 3.26 7.60 4 2.61 21.28 5 1.99 70.09 6 3.15 1.15 7 6.42 3.90 8 1.33 46.07 9 4.17 20.92 10 4.54 4.04 11 66.64 1.99 12 16.36 4.42 13 4.30 15.78 14 69.83 5.82 15 13.77 13.69 16 8.68 124.66 17 16.09 4.88 18 8.04 15.26 19 37.38 8.03 20 32.87 20.31 14 TABLE 2: Mean values for the Coefficient of Variability computed for the taxonomic hierarchy. gégggglg GENERA FAMILIES SUPERFAMILIES ORDERS l 46.74 45.79 31.23 20.30 2 41.30 42.94 35.86 35.57 3 42.19 60.73 52.01 41.08 4 39.70 44.26 38.21 45.19 5 57.37 56.35 37.21 55.11 6 32.02 32.84 48.83 50.60 7 44.85 38.33 47.61 52.76 8 28.70 65.84 43.29 53.92 9 36.27 40.94 45.49 63.33 10 43.40 46.78 54.75 48.26 11 35.74 67.27 46.55 53.96 12 48.37 61.85 27.53 55.59 13 51.81 59.39 45.42 65.94 14 56.64 49.45 47.19 59.01 15 42.29 54.16 35.04 62.79 16 43.04 47.64 51.07 58.16 17 44.21 35.02 64.74 72.05 18 40.30 45.76 52.90 59.58 19 42.61 38.42 44.35 52.93 20 54.93 44.49 36.39 59.91 15 16 harmonic also has a constant CV, ranging from 35.57 to 42 94. Table 2 shows that all harmonic frequencies (1-20) contribute shape information at all levels in the taxonomic hierarchy. The complexity of a suture pattern can be roughly quan— tified as the number of harmonic frequencies required to reduce root mean square error to 0.05 or less. The average number to reduce RMS to 0.05 or less is seven for the nautiloids and eleven for the ammonoids. Those ammonoid approximations which could not reduce RMS to 0.05 were not included in the computa- tion of this average. Sixteen harmonics were the maximum number required to reduce RMS to 0.05 or less in the nautiloids. The ammonoids differ form the nautiloids primarily in the increased signal of the higher order harmonics (Figures 3 and 4). This is an expected result of the ammonoids' increase in sutural complex- ity by the addition of lateral lobes, which are not found in the nautiloids. The mean power spectrum of the Subclass Ammonoidea was computed from the four power spectra shown in Figure 5. These are the mean harmonic amplitudes of the Orders Anarcestida, Clymeniida, Goniatitida and Cerititida. The mean suture pat- terns which these power spectra represent were redrawn by FORTRAN program FILTER (Appendix F) and are presented in Figures 6 and 7). Discrimminant analysis (Nie, et al., 1975, p. 434-467) was performed using these four Orders as the clas— sification categories. Only nine individuals out of 129 were 17 FIGURE 3: Mean power spectra of Subclass Ammonoidea (A) and Subclass Nautiloidea (N). mumzaz >uzmaowmm u~zozm¢z a. S m. 2. Sr a .. m m . 17a P 4 db ~m.~n <> 4P 4 by q 4» 1 c101 z.mY quuduJ .émn.~- .6mfl.un .6mo.~u .ého.¢l : {OnF-ul 16mm._| lémn.—I .énN.—I .bbo.—t um.l 3001116148 DINOHBUH N83“ 001 18 FIGURE 4: Mean sutures of Subclasses Nautiloidea (A) and Ammonoidea (B) and a graphic display of the difference between them (C). 19 FIGURE 5: Power spectra of the mean suture patterns of Ammonoid Orders Anarcestida, Clymen— iida, Goniatitida, and Cerititida. 19a ”N mum—.52 >ozmzau¢m u H 202mm: 2. 2. 3. 2. .2. _ o. p. u. a. 8.» 2.5.. o 5:28 1T .... 65.5 a ‘ 8S- Bugs... 9 a. .. 99“.. .68.“- 0‘)??- u..- / a... ‘ .. .4» I R) \nf ...B ...... & \... I ., .93 a, \ i... ‘0: .. o... I .000. u... .. . no. ‘8’ co .uoo.u 301.! 1JHU 3 I NONHUH 001 20 FIGURE 6: Mean sutures of Orders Anarcestinda (A) and Clymeniida (B) and a graphic display of the difference between them (C). 21. FIGURE 7: Mean sutures of Orders Goniatitida (A) and Cerititida (B) and a graphic display of the difference between them (C). 22 misclassified (Table 3). This result is significant at a = .01 withX2 = 318.35. The sensitivity of Fourier shape anal— ysis to genetic differences at high taxonomic levels is dem- onstrated by the above results. The ability to filter nongenetic effects from the mor- phologic information, leaving only genetically regulated shape information, is of great importance to the studies of taxonomy, ontogeny, and phylogeny. The data set included only two complete suture patterns suitable for examing both halves. Both suture patterns were of Acanthoclymenia neapolitana, at 2% volutions of the conch and at maturity. Each suture half was processed eight to ten times. Discriminant analysis was perfomred upon the harmonic ampli- tudes and 100% correct classification (1:2 = 105.00) was achie- ved (Table 4). The significant differences between left and right suture halves are summarized in the mean power spectra of these sutures (Figure 8) These differences are not dis— cernible in visual inspection of the suture patterns. The ontogenetic sequences of sutre patterns of Adrianites dunbari, Agatherisis uralicum and Koenenites cooperi (taken from Arkell, et al., 1957) were studied. Suture patterns which were too complex for analysis i.e., those which requre a double valued function) were omitted. Sutural complexity, as measured by the number of harmonics required to reduce RMS to 0.05 or less, increased with age in each of the three sequences. Because of the elimination of the complex mature sutures of A. dunbari and A. Uralicum, further study of ontogeny was limited to E. cooperi. 23 N .00. No.0 No.0 No.0 o.NN 0.0 0.0 0.0 mm mopuaomumo N0.N No.00 No.0 N .0 0.. 0.N0 0.0 0.0 om 00N0N00N000 No.0 No.0 No.0N N .mm 0.0 0.0 0.0. 0.0 m. moaacmENH0 No.0 N0.N No.0 NN.mo 0.0 0.. 0.N o..0 00 mocaommoumca aoHeHeammo aoHeaHzoo <0HHzmzwao <02H00000umaapm ”m mumDhum N .0 No.0 No.0 No.ooa 0.0 0.0 0.0 o.m m quzm>Dhuq HADQ¢-M HADQDw-m quzm>Dhuq mmmDm Loom Cm mo>Hm£ ousudm unwwu paw umoa coo3uon cowumcwswuomwp uoowuom .mcmufiaommoc mNcoENHoonucmo< Scum pump mo mHm>Hmc< oumcfiawuomwn mo humeadm no mqmuzu3awxm uuzo:mc: 0. 2 0. 2 z 0 .. 0 n . . .. x .1 0 v x . 0 180.0- 000.00.. 0. e 230...? ... N522... .0. 1.8.0- .. . :32... .0. .. 0.9.... 300111JUU JINOHUUH NUBH 001 26 Figure 9 is the power spectra of the harmonic amplitudes of the six sutures in the ontogenetic series of M. cooperi as reported by Miller (1938). Growth and development is re- flected in the power spectra as a slow broadening and migra— tion of the first peak of the series to higher order harmonic frequencies. Each successive approximation (i.e., suture) tends to be of a higher overall power spectrum than the pre- vious one. This visual observation is supported by ranking the approximation at each frequency and summing the ranks over the approximations (Table 5). The above observation fit Miller's description of the ontogeny as proceeding by the subdivision of lobes and increase in size. A phylogenetic sequence of sutures proposed by Miller (Arkell, et al. p. 134, 1957) for the Family Gephuroceratidae was studied in the same manner as the ontogeny of sutures in M. cooperi. The sequence consisted of Ponticeras aquabilis, Manticoceras simulator, Manticoceras sinuosum, Koenenenites cooperi and Timanites keyserlingi. The complete sutures of M. simulator was not available in the literature and could not be included. The same problem forced substitution of Ponticeras stainbrooki for E. aequabilis. P. stainbrooki, which has the most simple suture, forming only four distinct lobes (Arkell et al., p. 135, 1957), has a peak in its power spectrum (Figure 10) at the fourth harm- onic frequency and then drops for the higher order frequencies. M. sinuosum, M. cooperi and T. keyserlingi should then be ex- pected to have peaks at frequencies six, eight and ten, 27 FIGURE 9: Power spectra of the ontogenetic series of sutures in Koenenites cooperi. 27%: X INCA l 0025 I ma \ ”NH” MK! a mu: -+-mna I, -L1u$1? h I I -Ls4-, I -nav‘ -maufi -24nq- ::14 300111JHU N83" 001 21 10 HRRHONIC FREQUENCY NUHBER TABLE 5: Rankings of the harmonic amplitudes within each harmonic frequency for six suture patterns in the ontogenetic series of Koenenites cooperi. The increase in rank sums with age is a response to a general increase in signal with age. VOLUTION OF CONCH 0.5 1.5 2.5 3.5 4.5 5.5 HARMONIC NUMBER RANKINGS OF HARMONIC AMPLITUDES l 5 4 l 2 3 6 2 3 l 2 5 6 4 3 2 l 3 5 6 4 4 l 3 6 4 5 2 5 3 4 2 5 l 6 6 2 l 3 4 6 5 7 l 3 2 4 5 6 8 l 2 4 5 3 6 9 3 2 l 4 6 r 10 l 2 3 4 5 6 ll 2 3 4 5 6 l 12 l 3 2 4 6 5 l3 2 3 l 4 5 6 l4 2 4 l 6 5 3 15 l 3 2 5 6 4 l6 1 2 3 4 5 6 l7 1 3 4 5 2 6 l8 1 2 4 3 5 6 l9 1 2 4 3 5 6 20 .1__ _2_ _4_ .1 a... _5__ Ranking Sums 35 50 56 87 95 97 28 FIGURE 10: 29 Power sectra of the four sutures in the phylogenetic series in the Family Gephuroceratidae. SEQl = P. SEQ3 SE05 M. :. sinuosum, SEQ4 =_M. keyserlingi stainbrooki 9.992221. 29a 21 “33'." 5> “F: “3:132:90 17 '18 13 l V '11 HRRHON IC FREQUENCY NUHBER 300.111.1118 N83“ 0 30 corresponding to their respective number of lobes (Arkell et al., p. 135, 1957). M. sinuosum and M. cooperi do have high values where expected, but these are not their maximua T. keyserlingi has a relatively low value for its tenth harmonic amplitude. These anomolies are considered to be the results of combinations of lower order frequencies making good approx- imations to the fit of the data, leaving less residual signal to be accounted for by the higher order frequencies. The asymmetric, non-regular (variable frequency) nature of the lobes of I. keyserlingi can be better approximated by the combination of two signals, the fourth and the seventh harm- onic frequencies, than by the tenth frequency. A measure of the similarity of the sutures within a group- ing can be made by calculating the normalized roughness co- efficient (RC) of each suture pattern. fi 20 J. 25 Z (Aij/ A1) i=1 RC where Aij is the harmonic amplitude of the ith frequency in the jth suture, and Xi is the mean harmonic amplitude of the ith frequency. A set of identical sutures should all have values of RC equal to 10 or 3.1623. The phylogenetic sequence has value of RC ranging from 2.9135 for I. keyserlingi to 4.7666 for M. sinuosum. The ontogenetic sequence ranges from 1.6082 at the earliest suture to 7.4351 at the adult suture. This indicates that the sutures of the phylogenetic series are less differ- ent from each other than those of the ontogenetic series. 31 The sources of the variation can be determined by ex- amining the coefficients of variability for the two sequences (Table 6). The phylogenetic sequence only has two values of CV greater than 100 (harmonics twelve, thirteen). Other sources of variation are, in descending order, harmonics six, fourteen, sixteen, eleven, and one. The ontogenetic sequence has six harmonics with coefficients of variability greater than 100. Only harmonics one, two, four, six, twelve, four- teen and sixteen have lower values of CV in the ontogenetic sequence than in the phylogenetic sequence. The extremely low values of CV for harmonics two and four in the ontogenetic series indicate that these harmonic frequencies are relatively independent of development, and reflect a basic sutural form that does not vary with growth. Log transforms of the harmonic amplitudes form the suture patterns of the ontogenetic series were submitted to prin- cipal components factor analysis (Nye, et al., p. 468-514, 1970). The number of volutions of the conch at each suture was included as a variable representing age. Also included were log transforms of the size of the aperature and twenty harmonic amplitudes computed in closed form (Ehrlich and Wein- berh, 1970; Ewald, 1975; Anstey, Pachut and Prezbindowski, 1976) from the shape of the aperature at the respective number of volutions. The matrix of correlations, output as a preliminary re- sult, shows significant (a = .05) correlations of age with size, sutural harmonic frequencies zero, six, seven, ten, TABLE 6: Coefficients of Variation of the harmonic amplitudes, computed from the phylogentic series in the Family Gephuroceratidae and the onto- genetic series in Koenenites cooperi. HARMONIC NUMBER COEFFICIENT OF VARIATION Phylogeny Ontogeny l 80.14 76.61 2 67.25 32.53 3 56.67 61.68 4 52.41 39.45 5 64.15 114.58 6 95.35 68.16 7 52.95 78.82 8 70.77 84.23 9 51.54 76.68 10 76.93 113.23 11 80.68 123.17 12 104.56 67.60 13 113.84 153.60 14 88.63 66.56 15 43.61 93.68 16 87.28 65.48 17 46.38 117.06 18 55.36 119.19 19 62.38 71.61 20 52.28 81.46 32 33 twelve, sixteen, eighteen, twenty and aperatural harmonic frequencie four (Table 7). All of these variables load most heavily on the first principal component (Table 8) or the general growth factor (Gould, 1966). Principal components analysis of the phylogenetic se- quence was performed using a dummy ”SEQ" variable coded as the log of the suture's position in the series. As before, log transforms of the harmonic amplitudes were used. No aperatural shapes were available for the study. Only har- monic frequencies seven, eighteen and twenty were signifi- cantly (a = .05) correlated with "SEQ" (Table 9). These four variables all loaded most highly on Factor two (Table 10). The correlation of harmonic frequencies seven and eigh- teen with age in both the ontogenetic and the phyloeneetic series is an interesting point. The seventh harmonic is re- sponsible, in part, for the presence of lateral lobes. The eighteenth harmonic frequency is equivalent to eighteen evenly spaces lobes. Alone, its effect can only be in small scale sculpturing of the suture patterns. However, the high levels of correlation imply an interaction of the two variables. The results of this interaction is demonstrated by Figure 11, which shows the actual contribution of harmonic frequencies seven and eighteen to the approximation of the earliest and adult sutures of M. cooperi. The log transformation of the two harmonic amplitudes were plotted against each other and regression lines were com- puted (Figures 12 and 13) for the ontogenetic and phylogenetic data. The slopes of the regression lines are 0.593 for the TABLE 7: Significant Correlation Coefficients (R) of variables from the study of ontogeny in Koenenites cooperi. Significance level is a=.05 and a=.01(*) Sutural variables are HARM l to HARM 20 and HZERO. Aperatural variables are AHARM 1 to AHARM 20 and SIZE. AGE SIZE Size .97982* HARM 6 .82005 HARM 6 .88217 HARM 7 .97274* HARM 7 .85522 HARM 8 .89910 HARM 10 .86423* HARM 9 .98817* HARM 12 .81744 HARM 16 .95864* HARM 16 .99448* HARM 17 .88508 HARM 18 .95072* HARM 18 .95433* HARM 20 .85268 AHARM 2 -.82488 AHARM 4 .87485 AHARM 4 .83539 HZERO .84909 HARM 1 HARM 2 AHARM 1 -.95539* HARM 3 .94236* AHARM 8 -.92109* AHARM 9 -.95587* AHARM 12 -.94688* AHARM 13 -.83069 HARM 3 AHARM 17 -.90256 AHARM 18 -.85346 HARM 15 .88907 HARM 4 HARM 5 AHARM 3 .92283* HARM 17 .86010 AHARM 7 .99258* AHARM 2 -.92246 AHARM 11 .95408* AHARM 16 .91773* HZERO .85889 HARM 6 HARM 7 HARM 7 .81684 HARM 8 .86530 HARM 10 .86140 HARM 10 .95855 HARM 12 .82726 HARM 13 .89130 HARM 16 .86628 HARM 16 .94243* HARM 18 .86439 HARM 17 .82926 HARM 20 .81644 HARM 18 .89193 34 TABLE 7 cont. HARM 8 HARM 10 .82804 HARM 16 .85520 HARM 17 .95015* HARM 18 .81873 HARM 19 .82126 HZERO .83168 HARM 10 HARM 16 .93151* HARM 17 .85613 HARM 18 .95146* AHARM 2 -.83102 HARM 12 HARM 15 .87466 HARM 16 .84243 AHARM 16 .83725 HARM 16 HARM 18 .92970* HARM 20 .87048 AHARM 3 .84199 AHARM 4 .88852 AHARM 16 .86241 HZERO .89209 HARM 18 HARM 20 .88226 AHARM 4 .83301 AHARM 10 -.84336 35 HARM HARM AHARM AHARM AHARM AHARM HARM AHARM HZERO HARM AHARM AHARM AHARM AHARM HZERO HARM 9 13 .88184 14 .87175 HARM 11 1 .83761 5 -.90542 12 .88750 17 .87568 HARM 15 16 .83718 16 .82249 .89209 HARM 17 19 .86686 2 -.85699 HARM 20 3 .88562 4 .91223 16 .82590 .82147 TABLE 7 cont. AHARM 1 AHARM 8 .95857* AHARM 9 .90245 AHARM 12 .97886* AHARM 13 .89945 AHARM 17 .96507* AHARM 18 .95515* AHARM 19 .87201 AHARM 4 AHARM 13 .83189 HZERO .91379 AHARM 7 AHARM 11 .91470 AHARM 16 .93642* HZERO .90564 AHARM 9 AHARM 12 .86207 AHARM 17 .84155 AHARM 12 AHARM 13 .87988 AHARM 17 .95505* AHARM 18 .89848 AHARM 16 HZERO .92995* AHARM 18 AHARM 19 .95388* 36 AHARM AHARM 4 AHARM 7 AHARM 13 AHARM l6 HZERO AHARM AHARM 15 AHARM AHARM 9 AHARM 12 AHARM 13 AHARM 17 AHARM 18 AHARM l9 AHARM AHARM 16 AHARM AHARM l7 AHARM 18 AHARM 19 HZERO AHARM AHARM 18 AHARM 19 .88997 .95938 .87177 .95328* .96608* .88451 .93093 .88597 .81726 .88752 .93639* .92850* 11 .81148 13 .91031 .94541* .84781 .82988 17 .93180* .85166 37 mHHoH. mcqu.- mmomo.u «whom. oomwm. om zm .oamxm oppupm mo oppuHHmEm oHcoEMms nuouou map mH ommmzm mo umpEb: osu mH mu< .Huomooo mouHcocooM mo moHuom oHuosowouco onu pH mocmcm ousumuomm ppm mounusm me Eoum pouaaaoo .GOHumuHHmauoc nomHmM fiuHB coHumuou Hmumm xHuumE uoOomm poumuou meHum> ”w mHm .ucoo m mHm