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Directional evolution in the conodont Pterospathodus

Published online by Cambridge University Press:  08 April 2016

David Jones*
Affiliation:
Department of Geology, University of Leicester, Leicester LE1 7RH, United Kingdom. E-mail: doj2@le.ac.uk

Abstract

The excellent fossil record of conodonts represents an ideal, yet underutilized, resource for resolving fundamental issues of pattern and process in evolutionary theory. However, this potential has not been exploited because the quantitative understanding of the evolution of conodont element morphology is limited. This work applies standardized morphometric protocols to skeletal elements belonging to the conodont Pterospathodus, derived from a densely sampled section from Estonia. It has established a robust quantitative framework for morphological variation in Pterospathodus, permitting statistical analysis of the current qualitative hypotheses of evolutionary pattern within this genus for the first time. Apparent directional trends were statistically compared with patterns expected for directional evolution, an unbiased random walk and stasis, using maximum-likelihood model fitting, rescaled range analysis, and the runs test. Results confirmed the presence of trends in size and shape change through time, providing an example of convincing directional morphological change in a fossil lineage. The morphometric analyses have also allowed quantitative investigation of ontogenetic processes in Pterospathodus, suggesting that allometric repatterning was the proximal mechanism responsible for mediating the observed shifts in morphology through time. The results have demonstrated that conodonts represent an important resource for understanding evolutionary pattern and process in the fossil record.

Type
Articles
Copyright
Copyright © The Paleontological Society 

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References

Literature Cited

Alberch, P., Gould, S. J., Oster, G. F., and Wake, D. B. 1979. Size and shape in ontogeny and phylogeny. Paleobiology 5:296317.Google Scholar
Aldridge, R. J., and Purnell, M. A. 1996. The conodont controversies. Trends in Ecology and Evolution 11:463468.Google Scholar
Barnett, S. G. 1971. Biometric determination of the evolution of Spathognathodus remscheidensis: a method for precise intrabasinal time correlations in the Northern Appalachians. Journal of Paleontology 45:274300.Google Scholar
Barnett, S. G. 1972. The evolution of Spathognathodus remscheidensis in New York, New Jersey, Nevada, and Czechoslovakia. Journal of Paleontology 46:900917.Google Scholar
Barrick, J. E., and Männik, P. 2005. Silurian conodont biostratigraphy and paleobiology in stratigraphic sequences. In Purnell, M. A. and Donoghue, P. C. J., eds. Conodont biology and phylogeny: interpreting the fossil record. Special Papers in Palaeontology 73:103116. Palaeontological Association, London.Google Scholar
Bell, M. A., Travis, M. P., and Blouw, D. M. 2006. Inferring natural selection in a fossil threespine stickleback. Paleobiology 32:562577.CrossRefGoogle Scholar
Benton, M. J., and Emerson, B. C. 2007. How did life become so diverse? The dynamics of diversification according to the fossil record and molecular phylogenetics. Palaeontology 50:2340.Google Scholar
Bookstein, F. L. 1987. Random-walk and the existence of evolutionary rates. Paleobiology 13:446464.Google Scholar
Bookstein, F. L. 1988. Random-walk and the biometrics of morphological characters. Evolutionary Biology 23:369398.CrossRefGoogle Scholar
Broadhead, T. W., and McComb, R. 1982. Paedomorphosis in the conodont family Icriodontidae and the evolution of Icriodus. Fossils and Strata 15:149154.Google Scholar
Bush, A. M., Powell, M. G., Arnold, W. S., Bert, T. M., and Daley, G. M. 2002. Time-averaging, evolution, and morphologic variation. Paleobiology 28:925.Google Scholar
Chikhi, L., Bonhomme, F., and Agnese, J. F. 1998. Low genetic variability in a widely distributed and abundant clupeid species, Sardinella aurita. New empirical results and interpretations. Journal of Fish Biology 52:861878.Google Scholar
Crampton, J. S. 1995. Elliptic Fourier shape-analysis of fossil bivalves—some practical considerations. Lethaia 28:179186.Google Scholar
Crampton, J. S., and Gale, A. S. 2005. A plastic boomerang: speciation and intraspecific evolution in the Cretaceous bivalve Actinoceramus. Paleobiology 31:559577.Google Scholar
Crampton, J. S., and Haines, A. J. 1996. Users' manual for programs HANGLE, HMATCH, and HCURVE for the Fourier shape analysis of two-dimensional outlines. Institute of Geological and Nuclear Sciences, Lower Hutt, N.Z.Google Scholar
Crônier, C., Renaud, S., Feist, R., and Auffray, J. C. 1998. Ontogeny of Trimerocephalus lelievrei (Trilobita, Phacopida), a representative of the Late Devonian phacopine paedomorphocline: a morphometric approach. Paleobiology 24:359370.Google Scholar
Donoghue, P. C. J., Purnell, M. A., and Aldridge, R. J. 1998. Conodont anatomy, chordate phylogeny and vertebrate classification. Lethaia 31:211219.Google Scholar
Donoghue, P. C. J., Purnell, M. A., Aldridge, R. J., and Zhang, S. 2008. The interrelationships of complex conodonts (Vertebrata). Systematic Palaeontology 6:119153.Google Scholar
Ehrlich, R., and Full, W. E. 1986. Comments on “Relationships among eigenshape analysis, Fourier analysis, and analysis of coordinates” by F. James Rohlf. Mathematical Geology 18:855858.Google Scholar
Erwin, D. H. 2000. Macroevolution is more than repeated rounds of microevolution. Evolution and Development 2:7884.Google Scholar
Evans, A. R. 2005. Connecting morphology, function and tooth wear in microchiropterans. Biological Journal of the Linnean Society 85:8196.Google Scholar
Evans, A. R., and Sanson, G. D. 2003. The tooth of perfection: functional and spatial constraints on mammalian tooth shape. Biological Journal of the Linnean Society 78:173191.Google Scholar
Evans, A. R., and Sanson, G. D. 2006. Spatial and functional modelling of carnivore and insectivore molariform teeth. Journal of Morphology 267:649662.Google Scholar
Falster, D. S., Warton, D. I., and Wright, I. J. 2006. SMATR: standardised major axis tests and routines, Version 2.0.Google Scholar
Ferson, S., Rohlf, F. J., and Koehn, R. K. 1985. Measuring shape variation of two-dimensional outlines. Systematic Zoology 34:5968.CrossRefGoogle Scholar
Flessa, K. W., and Kowalewski, M. 1994. Shell survival and time-averaging in nearshore and shelf environments: estimates from the radiocarbon literature. Lethaia 27:153165.Google Scholar
Foote, M., and Sepkoski, J. J. Jr. 1999. Absolute measures of the completeness of the fossil record. Nature 398:415417.Google Scholar
Full, W. E., and Ehrlich, R. 1986. Fundamental problems associated with “Eigenshape Analysis” and similar “Factor” analysis procedures. Mathematical Geology 18:451463.Google Scholar
Gerber, S., Neige, P., and Eble, G. J. 2007. Combining ontogenetic and evolutionary scales of morphological disparity: a study of early Jurassic ammonites. Evolution and Development 9:472482.Google Scholar
Giardina, C. R., and Kuhl, F. P. 1977. Accuracy of curve approximation by harmonically related vectors with elliptical loci. Computer Graphics and Image Processing 6:277285.Google Scholar
Gingerich, P. D. 1974. Size variability of teeth in living mammals and diagnosis of closely related sympatric species. Journal of Paleontology 48:895902.Google Scholar
Gingerich, P. D. 1983. Rates of evolution: effects of time and temporal scaling. Science 222:159161.Google Scholar
Gingerich, P. D. 1993. Quantification and comparison of evolutionary rates. American Journal of Science 293-A:453478.Google Scholar
Gingerich, P. D. 2001. Rates of evolution on the time scale of the evolutionary process. Genetica 112:127144.Google Scholar
Girard, C., Renaud, S., and Korn, D. 2004a. Step-wise morphological trends in fluctuating environments: evidence in the Late Devonian conodont genus Palmatolepis. Geobios 37:404415.Google Scholar
Girard, C., Renaud, S., and Sérayet, A. 2004b. Morphological variation of Palmatolepis Devonian conodont: species versus genera. Comptes Rendus Palevol 3:18.Google Scholar
Gradstein, F. M., Ogg, J. G., Smith, A. G., Bleeker, W., and Lourens, L. J. 2004. A new Geologic Time Scale, with special reference to Precambrian and Neogene. Episodes 27:83100.Google Scholar
Grant, W. S., and Bowen, B. W. 2006. Living in a tilted world: climate change and geography limit speciation in Old World anchovies (Engraulis; Engraulidae). Biological Journal of the Linnean Society 88:673689.Google Scholar
Grantham, T. 2007. Is macroevolution more than successive rounds of microevolution? Palaeontology 50:7585.Google Scholar
Haines, A. J., and Crampton, J. S. 2000. Improvements to the method of Fourier shape analysis as applied in morphometric studies. Palaeontology 43:765783.Google Scholar
Hammer, Ø., Harper, D. A. T., and Ryan, P. D. 2001. PAST: paleontological statistics software package for education and data analysis. Palaeontologia Electronica 4, Article 4.Google Scholar
Henderson, C. M., Mei, S., and Wardlaw, B. R. 2002. New conodont definitions at the Guadalupian-Longpingian boundary. In Hills, L. V., Henderson, C. M., and Bamber, E. W., eds. Carboniferous and Permian of the world. Canadian Society of Petroleum Geologists Memoir 19:725735.Google Scholar
Hendry, A. P., and Kinnison, M. T. 1999. Perspective: the pace of modern life: measuring rates of contemporary microevolution. Evolution 53:16371653.Google Scholar
Hendry, A. P., and Kinnison, M. T. 2001. An introduction to microevolution: rate, pattern, process. Genetica 112:18.Google Scholar
Hunt, G. 2004a. Phenotypic variance inflation in fossil samples: an empirical assessment. Paleobiology 30:487506.Google Scholar
Hunt, G. 2004b. Phenotypic variation in fossil samples: modeling the consequences of time-averaging. Paleobiology 30:426443.2.0.CO;2>CrossRefGoogle Scholar
Hunt, G. 2006. Fitting and comparing models of phyletic evolution: random walks and beyond. Paleobiology 32:578601.CrossRefGoogle Scholar
Hunt, G. 2007. The relative importance of directional change, random walks, and stasis in the evolution of fossil lineages. Proceedings of the National Academy of Sciences USA 104:1840418408.CrossRefGoogle ScholarPubMed
Hunt, G., Bell, M. A., and Travis, M. P. 2008. Evolution toward a new adaptive optimum: phenotypic evolution in a fossil stickleback lineage. Evolution 62:700710.Google Scholar
Hurst, H. E. 1951. Long-term storage capacity of reservoirs. Transactions of the Society of Civil Engineers 116:770808.Google Scholar
Huxley, J. S. 1924. Constant differential growth-rates and their significance. Nature 114:895896.Google Scholar
Jablonski, D. 1997. Body-size evolution in Cretaceous molluscs and the status of Cope's rule. Nature 385:250252.Google Scholar
Jones, D., and Purnell, M. 2007. A new semi-automated morphometric protocol for conodonts and a preliminary taxonomic application. In MacLeod, N., ed. Automated object identification in systematics. Systematic Association Special Volume 74:239260.Google Scholar
Kowalewski, M. 1996. Time-averaging, overcompleteness and the geological record. Journal of Geology 104:317326.Google Scholar
Kucera, M., and Malmgren, B. A. 1998. Differences between evolution of mean form and evolution of new morphotypes: an example from Late Cretaceous planktonic foraminifera. Paleobiology 24:4963.CrossRefGoogle Scholar
Kuhl, F. P., and Giardina, C. R. 1982. Elliptic Fourier features of a closed contour. Computer Graphics and Image Processing 18:236258.Google Scholar
Lecompte, F., Grant, W. S., Dodson, J. J., Rodríguez-Sánchez, R., and Bowen, B. W. 2004. Living with uncertainty: genetic imprints of climate shifts in East Pacific anchovy (Engraulis mordax) and sardine (Sardinops sagax). Molecular Ecology 13:21692182.Google Scholar
Lohmann, G. P. 1983. Eigenshape analysis of micro-fossils: a general morphometric procedure for describing changes in shape. Journal of the International Association for Mathematical Geology 15:659672.Google Scholar
Lohmann, G. P., and Schweitzer, P. N. 1990. On eigenshape analysis. Pp. 145166in Rohlf, F. J. and Bookstein, F. L., eds. Michigan morphometric workshop. University of Michigan Museum of Geology, Ann Arbor.Google Scholar
Loydell, D. K. 1998. Early Silurian sea-level changes. Geological Magazine 135:447471.Google Scholar
MacLeod, N. 1999. Generalizing and extending the eigenshape method of shape visualization and analysis. Paleobiology 25:107138.Google Scholar
MacLeod, N. 2002. Geometric morphometrics and geological shape-classification systems. Earth Science Reviews 59:2747.Google Scholar
MacLeod, N., and Rose, K. D. 1993. Inferring locomotor behavior in Paleogene mammals via eigenshape analysis. American Journal of Science 293-A:300355.Google Scholar
Malmgren, B. A., Kucera, M., and Ekman, G. 1996. Evolutionary changes in supplementary apertural characteristics of the late Neogene Sphaeroidinella dehiscens lineage (planktonic foraminifera). Palaios 8:192206.Google Scholar
Männik, P. 1998. Evolution and taxonomy of the Silurian conodont Pterospathodus. Palaeontology 41:10011050.Google Scholar
Männik, P. 2007. An updated Telychian (Late Llandovery, Silurian) conodont zonation based on Baltic faunas. Lethaia 40:4560.Google Scholar
Männik, P., and Aldridge, R. J. 1989. Evolution, taxonomy and relationships of the Silurian conodont Pterospathodus. Palaeontology 32:893906.Google Scholar
Mei, S., Henderson, C. M., and Cao, C. 2005. Conodont sample-population approach to defining the base of the Changhsingian Stage, Lopingian Series, Upper Permian. Pp. 105121in Beaudoin, A. B., and Head, M. J., eds. The palynology and micro-palaeontology of boundaries. Geological Society of London, London.Google Scholar
Mitteroecker, P., Gunz, P., and Bookstein, F. L. 2005. Heterochrony and geometric morphometrics: a comparison of cranial growth in Pan paniscus versus Pan troglodytes. Evolution and Development 7:244258.Google Scholar
Mosher, L. C. 1970. New conodont species as Triassic guide fossils. Journal of Paleontology 44:737742.Google Scholar
Mousseau, T. A., and Roff, D. A. 1987. Natural selection and the heritability of fitness components. Heredity 59:181197.Google Scholar
Murphy, M. A., and Cebecioglu, M. K. 1984. The Icriodus steinachensis and 7. claudia lineages (Devonian conodonts). Journal of Paleontology 58:13991411.Google Scholar
Murphy, M. A., and Springer, K. B. 1989. Morphometric study of the platform elements of Amydrotaxis praejohnsoni n. sp. (Lower Devonian, Conodonts, Nevada). Journal of Paleontology 63:349355.Google Scholar
Nestor, H. 1997. Sedimentary cover: Silurian. Pp. 89106in Raukas, A. and Teedumäe, A., eds. Geology and mineral resources of Estonia. Estonian Academy Publishers, Tallinn.Google Scholar
Nestor, H., and Einasto, R. 1997. Formation of the territory: Ordovician and Silurian carbonate sedimentation basin. Pp. 192204in Raukas, A. and Teedumäe, A., eds. Geology and mineral resources of Estonia. Estonian Academy Publishers, Tallinn.Google Scholar
Nestor, V. 1994. Early Silurian chitinozoans of Estonia and North Latvia. Academia 4:1163.Google Scholar
Orchard, M. J. 1983. Epigondolella populations and their phylogeny and zonation in the Upper Triassic. Fossils and Strata 15:177192.Google Scholar
Polly, P. D. 2004. On the simulation of the evolution of morphological shape: multivariate shape under selection and drift. Palaeontologia Electronica 7, Article 7.Google Scholar
Purnell, M. A. 1994. Skeletal ontogeny and feeding mechanisms in conodonts. Lethaia 27:129138.Google Scholar
Purnell, M. A. 1995. Microwear on conodont elements and macrophagy in the first vertebrates. Nature 374:798800.Google Scholar
Purnell, M. A., and Donoghue, P. C. J. 2005. Between death and data: biases in interpretation of the fossil record of conodonts. In Purnell, M. A. and Donoghue, P. C. J., eds. Conodont biology and phylogeny: interpreting the fossil record. Special Papers in Palaeontology 73:725. Palaeontological Association, London.Google Scholar
Purnell, M. A., Donoghue, P. C. J., and Aldridge, R. J. 2000. Orientation and anatomical notation in conodonts. Journal of Paleontology 74:113122.Google Scholar
Purnell, M. A., Hart, P. J. B., Baines, D. C., and Bell, M. A. 2006. Quantitative analysis of dental microwear in threespine stickleback: a new approach to analysis of trophic ecology in aquatic vertebrates. Journal of Animal Ecology 75:967977.Google Scholar
Purnell, M. A., Bell, M. A., Baines, D. C., Hart, P. J. B., and Travis, M. P. 2007. Correlated evolution and dietary change in fossil stickleback. Science 317:18871887.Google Scholar
Raup, D. M. 1977. Probabilistic models in evolutionary paleobiology. American Scientist 65:5057.Google Scholar
Raup, D. M., and Crick, R. E. 1981. Evolution of single characters in the Jurassic ammonite Kosmoceras. Paleobiology 7:200215.Google Scholar
Ritter, S. M. 1989. Morphometric patterns in Middle Triassic Neogondolella mombergensis (Conodonta), Fossil Hill, Nevada. Journal of Paleontology 63:233245.Google Scholar
Rohlf, F. J. 1986. Relationships among eigenshape analysis, Fourier analysis, and analysis of coordinates. Mathematical Geology 18:845854.Google Scholar
Rohlf, F. J. 2003. tpsDIG, Version 1.37.Google Scholar
Roopnarine, P. D. 2001. The description and classification of evolutionary mode: a computational approach. Paleobiology 27:446465.Google Scholar
Roopnarine, P. D. 2003. Analysis of rates of morphologic evolution. Annual Review of Ecology, Evolution, and Systematics 34:605632.Google Scholar
Roopnarine, P. D., Byars, G., and Fitzgerald, P. 1999. Anagenetic evolution, stratophenetic patterns, and random walk models. Paleobiology 25:4157.Google Scholar
Roopnarine, P. D., Murphy, M. A., and Buening, N. 2004. Microevolutionary dynamics of the Early Devonian conodont Wurmiella from the Great Basin of Nevada. Palaeontologia Electronica 8, Article 3.Google Scholar
Roth, V. L. 1992. Quantitative variation in elephant dentitions: implications for the delimitation of fossil species. Paleobiology 18:184202.Google Scholar
Sadler, P. M., and Strauss, D. J. 1990. Estimation of completeness of stratigraphical sections using empirical-data and theoretical-models. Journal of the Geological Society, London 147:471485.Google Scholar
Schindel, D. E. 1980. Microstratigraphic sampling and the limits of paleontologic resolution. Paleobiology 6:408426.Google Scholar
Sheets, H. D., and Mitchell, C. E. 2001. Why the null matters: statistical tests, random walks and evolution. Genetica 112:105125.Google Scholar
Sweet, W. C. 1988. The Conodonta: morphology, taxonomy, paleoecology and evolutionary history of a long-extinct animal phylum. Clarendon, Oxford.Google Scholar
Sweet, W. C., and Donoghue, P. C. J. 2001. Conodonts: past, present, future. Journal of Paleontology 75:11741184.Google Scholar
Walliser, O. H. 1964. Conodonten des Silurs. Abhandlungen des Hessischen Landesamtes für Bodenforschung 41:1106.Google Scholar
Warton, D. I., Wright, I. J., Falster, D. S., and Westoby, M. 2006. Bivariate line-fitting methods for allometry. Biological Reviews 81:259291.Google Scholar
Webster, M., and Zelditch, M. L. 2005. Evolutionary modifications of ontogeny: heterochrony and beyond. Paleobiology 31:354372.Google Scholar
Zhang, S. X., Aldridge, R. J., and Donoghue, P. C. J. 1997. An Early Triassic conodont with periodic growth? Journal of Micro-palaeontology 16:6572.Google Scholar