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Ghost lineages and “mammalness”: assessing the temporal pattern of character acquisition in the Synapsida

Published online by Cambridge University Press:  20 May 2016

Christian A. Sidor
Affiliation:
Department of Organismal Biology and Anatomy, University of Chicago, Chicago, Illinois 60637-1508. E-mail: casidor@midway.uchicago.edu and jhopson@midway.uchicago.edu
James A. Hopson
Affiliation:
Department of Organismal Biology and Anatomy, University of Chicago, Chicago, Illinois 60637-1508. E-mail: casidor@midway.uchicago.edu and jhopson@midway.uchicago.edu

Abstract

The origin of mammals has been characterized as a gradual process, a claim based primarily on a well-preserved series of extinct nonmammalian synapsids (“mammal-like reptiles”) that span some 200 million years. In contrast to the origin of many other higher taxa, the origin of mammals from within cynodont-grade therapsids is not considered to coincide with a major morphological change, but rather to be simply the culmination of a series of more and more mammal-like transitional forms. To test these assertions, an asymmetrical cladogram extending from primitive “pelycosaurs” to morganucodontid mammaliaforms was created. Three different methodologies were then used to compare the amount of morphological change between nodes on this cladogram with the minimum missing time interval between each node, as inferred from sister taxon-based ghost lineages. In general, a statistically significant positive relationship was found, indicating that greater numbers of derived features tend to be correlated with longer ghost lineages. A significant correlation between the number of accumulated apomorphies and branching events was also found. Although the rate of character change was variable, in no case was a long ghost lineage associated with few apomorphies. These correlations are consistent with the hypothesis that rapid accumulation of derived features occurred relatively infrequently within the synapsid lineage leading toward mammals and that gradual character evolution predominated.

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Articles
Copyright
Copyright © The Paleontological Society 

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References

Literature Cited

Allin, E. F. 1975. Evolution of the mammalian middle ear. Journal of Morphology 147: 403438.Google Scholar
Allin, E. F. 1986. The auditory apparatus of advanced mammal-like reptiles and early mammals. Pp. 283294. Hotton, et al. 1986.Google Scholar
Allin, E. F. and Hopson, J. A. 1992. Evolution of the auditory system in Synapsida (“mammal-like reptiles” and primitive mammals) as seen in the fossil record. Pp. 587614. Webster, D. B., Fay, R. R., Popper, A. N.The evolutionary biology of hearing Springer, New York.Google Scholar
Anstey, R. L. and Pachut, J. L. 1995. Phylogeny, diversity history and speciation in Paleozoic bryozoans. Pp. 239284. Erwin, D. H., Anstey, R. L.New approaches to studying speciation in the fossil record Columbia University Press, New York.Google Scholar
Bennett, A. F. and Ruben, J. A. 1986. The metabolic and thermoregulatory status of therapsids. Pp. 207218. Hotton, et al. 1986.Google Scholar
Benton, M. J. 1990. Reptiles. Pp. 279300. McNamara, K. J.Evolutionary trends Belhaven, London.Google Scholar
Benton, M. J. 1994. Late Triassic to Middle Jurassic extinctions among the continental tetrapods: testing the pattern. Pp. 366398. in Fraser, and Sues, 1994.Google Scholar
Benton, M. J. and Clark, J. M. 1988. Archosaur phylogeny and the relationships of the Crocodylia. Pp. 295338. Benton, M. J.The phylogeny and classification of the tetrapods,. Volume 1. Amphibians, reptiles, birds (Systematics Association Special Volume No. 35A) Clarendon, Oxford.Google Scholar
Bonaparte, J. F. 1980. El primer ictidosaurio (Reptilia—Therapsida) de America del Sur, Chaliminia musteloides, del Triassico Superior de La Rioja, República Argentina. Actas II Congreso Argentino de Paleontología y Bioestratigrafía y I Congreso Latinoamerico de Paleontología. 123133.Google Scholar
Broom, R. 1932. The mammal-like reptiles of South Africa and the origin of mammals. Witherby, London.Google Scholar
Brinkman, D. and Eberth, D. A. 1983. The interrelationships of pelycosaurs. Breviora 473: 135.Google Scholar
Campbell, K. S. W. and Marshall, C. R. 1987. Rates and modes of evolution among Paleozoic echinoderms. Pp. 61100. Campbell, K. S. W., Day, M. F.Rates of evolution Allen and Unwin, London.Google Scholar
Cracraft, J. 1981. Pattern and process in paleobiology: the role of cladistic analysis in systematic paleontology. Paleobiology 7: 456468.CrossRefGoogle Scholar
Dilkes, D. W. and Reisz, R. R. 1996. First record of a basal synapsid ('mammal-like reptile') in Gondwana. Proceedings of the Royal Society of London B 263: 1165-170.Google Scholar
Donoghue, M. J. and Ackerly, D. D. 1996. Phylogenetic uncertainies and sensitivity analyses in comparative biology. Philosophical Transactions of the Royal Society of London B 351: 12411249.Google Scholar
Donoghue, M. J., Doyle, J. A., Gauthier, J., Kluge, A. G., and Rowe, T. 1989. The importance of fossils in phylogeny reconstruction. Annual Review of Ecology and Systematics 20: 431460.Google Scholar
Felsenstein, J. 1978. Cases in which parsimony or compatibility methods will be positively misleading. Systematic Zoology 27: 401410.CrossRefGoogle Scholar
Foote, M. 1996. On the probability of ancestors in the fossil record. Paleobiology 22: 141151.CrossRefGoogle Scholar
Fraser, N. C. and Sues, H-D. 1994. In the shadow of the dinosaurs: early Mesozoic tetrapods. Cambridge University Press, New York.Google Scholar
Gauthier, J., Kluge, A. G., and Rowe, T. 1988. Amniote phylogeny and the importance of fossils. Cladistics 4: 105209.Google Scholar
Goldman, N. 1990. Maximum likelihood inference of phylogenetic trees, with special reference to a Poisson process model of DNA substitution and to parsimony analysis. Systematic Zoology 39: 345361.Google Scholar
Hancox, P. J. and Rubidge, B. S. 1996. The first specimen of the Mid-Triassic dicynodont Angonisaurus from the Karoo of South Africa: implications for the dating and biostratigraphy of the Cynognathus assemblage zone, Upper Beaufort Group. South African Journal of Science 92: 391392.Google Scholar
Harland, W. B., Armstrong, R. L., Cox, A. V., Craig, L. E., Smith, A. G., and Smith, D. G. 1990. A geologic time scale 1989. Cambridge University Press, New York.Google Scholar
Hennig, W. 1966. Phylogenetic systematics. University of Illinois Press, Urbana.Google Scholar
Hopson, J. A. 1966. The origin of the mammalian middle ear. American Zoologist 6: 437450.CrossRefGoogle ScholarPubMed
Hopson, J. A. 1973. Endothermy, small size, and the origin of mammalian reproduction. American Naturalist 107: 466-452.Google Scholar
Hopson, J. A. 1991. Systematics of the nonmammalian Synapsida and implications for patterns of evolution in synapsids. Pp. 635693. Schultze, H.-P., Trueb, L.Origins of the higher groups of tetrapods: controversy and consensus Comstock, Ithaca, N.Y.Google Scholar
Hopson, J. A. 1994. Synapsid evolution and the radiation of non-eutherian mammals. Prothero, D. B., Schoch, R. M.Major features of vertebrate evolution. Short Courses in Paleontology 7: 190219. Paleontological Society, Knoxville, Tenn.Google Scholar
Hopson, J. A., Crompton, A. W., Dobzhansky, T., Hecht, M. K., and Steere, W. C. 1969. Origin of mammals. InEvolutionary Biology 3: 1571. Appleton-Century-Croft, New York.Google Scholar
Hopson, J. A. and Barghusen, H. R. 1986. An analysis of therapsid relationships. Pp. 83106. Hotton, et al. 1986.Google Scholar
Hotton, N., MacLean, P. D., Roth, J. J., and Roth, E. C. 1986. The ecology and biology of the mammal-like reptiles. Smithsonian Institution Press, Washington, D.C.Google Scholar
Jinling, L., Rubidge, B. S., and Zhenggwu, C. 1996. A primitive anteosaurid dinocephalian from China—implications for the distribution of earliest therapsid faunas. South African Journal of Science 92: 252253.Google Scholar
Kemp, T. S. 1982. Mammal-like reptiles and the origin of mammals. Academic Press, New York.Google Scholar
Kemp, T. S. 1985. Synapsid reptiles and the origin of higher taxa. Special Papers in Palaeontology 33: 175184.Google Scholar
Kermack, D. M. and Kermack, K. A. 1984. The evolution of mammalian characters. Croom Helm, London.Google Scholar
Kitching, J. W. 1977. The distribution of the Karoo vertebrate fauna, Memoir 1. Bernard Price Institute for Paleontological Research, University of Witwatersrand, Johannesburg.Google Scholar
Laurin, M. and Reisz, R. R. 1990. Tetraceratops is the oldest known therapsid. Nature 345: 249250.CrossRefGoogle Scholar
Laurin, M. 1996. The osteology and relationships of Tetraceratops insignis, the oldest known therapsid. Journal of Vertebrate Paleontology 16: 95102.Google Scholar
Lucas, S. G. and Luo, Z. 1993. Adelobasileus from the Upper Triassic of West Texas. Journal of Vertebrate Paleontology 13: 309334.Google Scholar
Luo, Z. and Wu, X-C. 1994. The small tetrapods of the lower Lufeng Formation, Yunnan, China. Pp. 251270. in Fraser, and Sues, 1994.Google Scholar
MacFadden, B. J. 1992. Fossil horses: systematics, paleobiology, and the evolution of the family Equidae. Cambridge University Press, New York.Google Scholar
Modesto, S. P. and Rybczynski, N. In press. The amniote faunas of the Russian Permian: implications for Late Permian terrestrial vertebrate biogeography. Benton, M. J., Kurochkin, E. N., Shishkin, M. A., Unwin, D. M., eds. The age of dinosaurs in Russia and Mongolia: fossil vertebrates from the Permian and Mesozoic of the former Soviet Union and Mongolia. Cambridge University Press, New York.Google Scholar
Norell, M. A. 1992. Taxic origin and temporal diversity: the effect of phylogeny. Pp. 89118. Novacek, M. J., Wheeler, Q. D.Extinction and phylogeny Columbia University Press, New York.Google Scholar
Norell, M. A. 1993. Tree-based approaches to understanding history: comments on ranks, rules, and the quality of the fossil record. American Journal of Science 293 (A): 407417.Google Scholar
Norell, M. A. and Novacek, M. J. 1992. Congruence between superpositional and phylogenetic patterns: comparing cladistic patterns with fossil records. Cladistics 8: 319337.Google Scholar
Novacek, M. J. 1992. Fossils, topologies, missing data, and the higher level phylogeny of eutherian mammals. Systematic Biology 41: 5873.Google Scholar
Olson, E. C. 1941. The origin of mammals based upon the cranial morphology of the therapsid suborders. Geological Society of America Special Paper 55: 1136.Google Scholar
Olson, E. C. 1959. The evolution of mammalian characters. Evolution 13: 344353.Google Scholar
Olson, E. C. 1962. Late Permian terrestrial vertebrates. U.S.A. and U.S.S.R. Transactions of the American Philosophical Society 52: 1224.Google Scholar
Olson, E. C. 1971. Vertebrate paleozoology. Wiley-Interscience, New York.Google Scholar
Olson, E. C. 1979. Biological and physical factors in the dispersal of Permo-Carboniferous terrestrial vertebrates. Pp. 227238. Gray, J., Boucot, A. J.Historical biogeography, plate tectonics, and the changing environment. Oregon State University Press, Corvallis.Google Scholar
Olson, E. C. 1986. Relationships and ecology of the early therapsids and their predecessors. Pp. 4760. Hotton, et al. 1986.Google Scholar
Parrish, J. M., Parrish, J. T., and Zeigler, A. M. 1986. Permian-Triassic paleogeography and paleoclimatology and implications for therapsid distribution. Pp. 109131. in Hotton, et al. 1986.Google Scholar
Reed, C. A. 1960. Polyphyletic or monophyletic ancestry of mammals, or: what is a class? Evolution 14: 314322.CrossRefGoogle Scholar
Reisz, R. R. 1972. Pelycosaurian reptiles from the Middle Pennsylvanian of North America. Bulletin of the Museum of Comparative Zoology 144: 2762.Google Scholar
Reisz, R. R. 1980. The Pelycosauria: a review of phylogenetic relationships. Pp. 553591. Panchen, A. L.The terrestrial environment and the origin of land vertebrates (Systematics Association Special Volume No. 15) Academic Press, London.Google Scholar
Reisz, R. R. 1986. Pelycosauria. Pp. 1102. Wellnhofer, P.Encyclopedia of paleoherpetology, Part 17A Gustav Fischer, Stuttgart.Google Scholar
Reisz, R. R. 1995. The palaeogeographic distribution of Permo-Carboniferous synapsids and the origin of therapsids. Barton, J. M., Y. E., Copperthwaite, eds. Centennial Geocongress Extended Abstracts 11: 788791. Geological Society of South Africa, Johannesburg.Google Scholar
Reisz, R. R. and Berman, D. S. 1986. Ianthasaurus hardestii n. sp., a primitive edaphosaur (Reptilia, Pelycosauria) from the Upper Pennsylvanian Rock Lake Shale near Garnett, Kansas. Canadian Journal of Earth Science 23: 7791.Google Scholar
Reisz, R. R., Berman, D. S., and Scott, D. 1992. The cranial anatomy and relationships of Secodontosaurus, an unusual mammal-like reptile (Synapsida: Sphenacodontidae) from the Early Permian of Texas. Zoological Journal of the Linnean Society 104: 127184.CrossRefGoogle Scholar
Romer, A. S. 1965. Possible polyphylety of the vertebrate classes. Zoologische Jarbuch 92: 143156.Google Scholar
Romer, A. S. 1969. The Chañares (Argentina) Triassic reptile fauna V. A new chiniquodontid cynodont, Probelesodon lewisi— cynodont ancestry. Breviora 333: 124.Google Scholar
Ross, C. A., Baud, A., and Menning, M. 1994. Pangea time scale. P. 10. Klein, G. D., Beauchamp, B., eds. Pangea: paleoclimate, tectonics, and sedimentation during accretion, zenith, and breakup of a supercontinent. Geological Society of America Special Paper 288: 10. Boulder, Colo.Google Scholar
Rowe, T. 1986. Osteological diagnosis of Mammalia, L. 1758, and its relationship to extinct Synapsida. Ph. D. dissertation. University of California, Berkeley.Google Scholar
Rowe, T. 1988. Definition, diagnosis, and the origin of Mammalia. Journal of Vertebrate Paleontology 8: 241264.Google Scholar
Rowe, T. 1993. Phylogenetic systematics and the early history of mammals. Pp. 129145. Szalay, F. S., Novacek, M. J., McKenna, M. C.Mammal phylogeny: Mesozoic differentiation, multituberculates, monotremes, early therians, and marsupials Springer, New York.Google Scholar
Rubidge, B. S. 1990. A new vertebrate biozone at the base of the Beaufort Group, Karoo Sequence (South Africa). Palaeontologica Africana 27: 1720.Google Scholar
Rubidge, B. S. 1995. Biostratigraphy of the Beaufort Group (Karoo Series), South Africa. Government Printer, Pretoria.Google Scholar
Rubidge, B. S., Kitching, J. W., and van den Heever, J. A. 1983. First record of a therocephalian (Therapsida, Pristerognathidae) from the Ecca of South Africa. Navorsinge van die Nasionale Museum Bloemfontein. 4: 229235.Google Scholar
Sidor, C. A. 1996. Early synapsid evolution, with special reference to the Caseasauria. Journal of Vertebrate Paleontology 16: 65A66A.Google Scholar
Sidor, C. A. and Hopson, J. A. 1995. The taxonomic status of the Upper Permian eotheriodont therapsids of the San Angelo Formation (Guadalupian), Texas. Journal of Vertebrate Paleontology 15: 53A.Google Scholar
Sigogneau-Russell, D. and Hahn, G. 1994. Late Triassic microvertebrates from central Europe. Pp. 197213. in Fraser, and Sues, 1994.Google Scholar
Simpson, G. G. 1959. Mesozoic mammals and the polyphyletic origin of mammals. Evolution 13: 405414.CrossRefGoogle Scholar
Swofford, D. L. 1993. PAUP (Phylogenetic analysis using parsimony), Version 3.1.Google Scholar