Hostname: page-component-84b7d79bbc-g5fl4 Total loading time: 0 Render date: 2024-07-26T12:17:24.114Z Has data issue: false hasContentIssue false

The Radiation of Placental Mammals

Published online by Cambridge University Press:  17 July 2017

Michael J. Novacek*
Affiliation:
Department of Vertebrate Paleontology, American Museum of Natural History, Central Park West at 79th Street, New York, New York 10024

Extract

The placental or eutherian mammals comprise about twenty living orders and several extinct ones. The morphological and adaptive range of this group is extraordinary; diversification has produced lineages as varied as humans and their primate relatives, flying bats, swimming whales, ant-eating anteaters, pangolins and aardvarks, a baroque extravagance of horned, antlered, and trunk-nosed herbivores (ungulates), as well as the supremely diverse rats, mice, beavers and porcupines of the order Rodentia. Such adaptive diversity, and the emergence of thousands of living and fossil species, apparently resulted from a radiation beginning in the late Mesozoic between 65 and 80 million years ago (Novacek, 1990). This explosive radiation (Figure 1) is one of the more intriguing chapters of vertebrate history, and the problem has attracted interest from unusually varied perspectives. As a result, eutherian mammals are known from a rapidly growing molecular database, as well as a wealth of morphological characters and a comparatively enriched fossil record. The interplay of molecular and morphological investigation is more apparent in the case of placental mammals that in any other vertebrates, perhaps more than in any other group of organisms.

Type
Research Article
Copyright
Copyright © 1994 Paleontological Society 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Adkins, R. M., and Honeycutt, R. L. 1991. Molecular phylogeny of the superorder Archonta. Proceedings of the National Academy of Science, 88:15.Google Scholar
Adkins, R. M., Miyamoto, M. M., and Honeycutt, R. L. 1991. Tests for rodent polyphyly. Nature, 353: 610611.Google Scholar
Ammerman, L. K., and Hillis, D. M. 1990. Relationships within archontan mammals based on 12S rRNA gene sequence. American Zoologist, 30:50A.Google Scholar
Ammerman, L. K., and Hillis, D. M. 1992. A molecular test of bat relationships: Monophyly or diphyly? Systematic Biology, 41: 222232.CrossRefGoogle Scholar
Aplin, K., and Archer, M. 1987. Recent advances in marsupial systematics, with a new syncretic classification, p. xvlxxii. In Archer, M. (ed.), Possums and Opossums: Studies in Evolution, Vol. 1. Royal Zoological Society, NSW, Sydney.Google Scholar
Arnason, U., and Ledje, C. 1993. The use of highly repetitive DNA for resolving cetacean and pinniped phylogenies, p. 7480. In Szalay, F. S., Novacek, M. J. and McKenna, M. C. (eds.), Mammal Phylogeny. Vol. II. Placentals. Springer Verlag, New York.Google Scholar
Bailey, W. J., Slightom, J. L., and Goodman, M. 1992. Rejection of the “flying primate” hypothesis by phylogenetic evidence from the e-globin gene. Science, 256: 8689.Google Scholar
Baker, R. J., Novacek, M. J., and Simmons, N. B. 1991. On the monophyly of bats. Systematic Zoology, 40: 216231.Google Scholar
Bauchot, R., and Stephan, H. 1966. Donnees nouvelles sur l' encephalisation des insectivores et des prosimiens. Mammalia, 30:160196.Google Scholar
Beard, K. C. 1990. Gliding behavior and palaeoecology of the alleged primate family Paromomyidae (Mammalia, Dermoptera). Nature, 345: 340341.Google Scholar
Beard, K. C. 1993. Phylogenetic systematics of the Primatomorpha, with special reference to Dermoptera, p. 129150. In Szalay, F. S., Novacek, M. J. and McKenna, M. C. (eds.), Mammal Phylogeny. Vol. II. Placentals. Springer Verlag, New York.CrossRefGoogle Scholar
Berta, A. 1994. What is a whale? Science, 263: 180181.Google Scholar
Blainville, H. M. D. 1816. Prodome d'une nouvelle distribution systematique de regne animal. Bulletin de la Societé Philomatique de Paris, 1816: 6781.Google Scholar
Brown, W. M., George, M., and Wilson, A. C. 1979. Rapid evolution of animal mitochondrial DNA. Proceedings, National Academy of Science, 76:19671971.Google Scholar
Butler, P. M. 1988. Phylogeny of the insectivores, p. 117141. In Benton, M. J. (ed.), The phylogeny and classification of the tetrapods, Vol. 2. Clarendon Press, Oxford.Google Scholar
Cifelli, R. L. 1993. The phylogeny of the native South American ungulates, p. 195216. In Szalay, F.S., Novacek, M. J. and McKenna, M. C. (eds.), Mammal Phylogeny. Placentals. Springer Verlag, New York.CrossRefGoogle Scholar
De Jong, W. W. 1982. Eye lens proteins and vertebrate phylogeny, p. 15114. In Goodman, M. (ed.), Macromolecular sequences in systematic and evolutionary biology. Plenum Press, New York.Google Scholar
De Jong, W. W., Leunissen, J. A. M., and Wistow, G. J. 1993. Eye lens crystallins and the phylogeny of placental orders: Evidence for a macroscelid-paenungulate clade? p. 512. In Szalay, F. S., Novacek, M. J. and McKenna, M. C. (eds.), Mammal Phylogeny. Placentals. Springer Verlag, New York.CrossRefGoogle Scholar
DeSalle, R., Gatesy, J., Wheeler, W., and Grimaldi, D. 1992. DNA sequences from a fossil termite in Oligo-Miocene amber and their phylogenetic implications. Science, 257: 19331936.CrossRefGoogle ScholarPubMed
Donoghue, M., Doyle, J., Gauthier, J., Kluge, A., and Rowe, T. 1989. The importance of fossils in phylogeny reconstruction. Annual Reviews of Ecology and Systematics, 20: 431460.Google Scholar
Edinger, T. 1964. Midbrain exposure and overlap in mammals. American Zoologist, 4: 519.CrossRefGoogle ScholarPubMed
Faith, D. P., and Cranston, P. S. 1991. Could a cladogram this short have arisen by chance alone? On permutation tests for cladistic structure. Cladistics, 7:128.CrossRefGoogle Scholar
Fay, F.H., Rausch, V. R., and Felitz, E. T. 1967. Cytogenetic comparison of some pinnipeds (Mammalia: Eutheria). Canadian Journal of Zoology, 45: 773778.Google Scholar
Fischer, M. S. 1989. Hyracoids, the sister group of Perissodactyls, p. 3756. In Prothero, D. R. and Schoch, R. M. (eds.), The Evolution of Perissodactyls. Oxford University Press, New York,Google Scholar
Fischer, M. S., and Tassy, P. 1993. The interrelation between Proboscidea, Sirenia, Hyracoidea, and Mesaxonia: The morphological evidence, p. 217234. In Szalay, F. S., Novacek, M. J. and McKenna, M. C. (eds.), Mammal Phylogeny. Placentals. Springer Verlag, New York.Google Scholar
Gall, J. G. 1981. Chromosome structure and the c-value paradox. Journal of Cell Biology, 91: 314.Google Scholar
Gaupp, E. 1913. Die Reichertsche Theorie (Hammer-, Amboss- und Kieferfrage). Archiv für Anatomie und Entwicklungsgeschichte, 1912:1416.Google Scholar
Gauthier, J., Kluge, A. G., and Rowe, T. 1988. Amniote phylogeny and the importance of fossils. Cladistics, 4: 105209.Google Scholar
Gingerich, P. D. 1986. Temporal scaling of molecular evolution in primates and other mammals. Molecular Biology and Evolution, 3: 205221.Google Scholar
Gingerich, P. D., Smith, B. H., and Simons, E. L. 1990. Hind limbs of Eocene Basilosaurus. Evidence of feet in whales. Science, 249: 154157.Google Scholar
Golenberg, E. M., Giannasi, D. E., Clegg, M. T., Smiley, C. J., Durbin, M., Henderson, D., and Zurawski, G. 1990. Chloroplast DNA sequence from a Miocene Magnolia species. Nature, 344: 656658.Google Scholar
Goodman, M. 1975. Protein sequence and immunological specificity, p. 219248. In Luckett, W. P. and Szalay, F.S. (eds.), Phylogeny of the Primates. Plenum Press, New York.Google Scholar
Goodman, M. 1989. Emerging alliance of phylogenetic systematics and molecular biology: a new age of exploration, p. 4361. In Fernholm, B., Bremer, K., and Jørnvall, H. (eds.), The Hierarchy of Life. Nobel Symposium 70. Elsevier Science Publications, Amsterdam.Google Scholar
Goodman, M., and Moore, G.W. 1971. Immunodiffusion in the systematics of primates. I. The Catarrhini. Systematic Zoology, 20: 1962.CrossRefGoogle Scholar
Goodman, M., Romero-Herrera, A. E., Dene, H., Czelusniak, J., and Tashian, R. 1982. Amino acid sequence evidence on the phylogeny of primates and other eutherians, p. 115191. In Goodman, M. (ed.), Macromolecular Sequences in Systematic and Evolutionary biology. Plenum Press, New York.Google Scholar
Goodman, M., Miyamoto, M. M., and Czelusniak, J. 1987. Pattern and process in vertebrate phylogeny revealed by coevolution of molecules and morphologies, p. 141176. In Patterson, C. (ed.), Molecules and Morphology in Evolution: Conflict or compromise? Cambridge University Press, Cambridge.Google Scholar
Graur, D. 1993. Molecular phylogeny and the higher classification of eutherian mammals. Trends in Ecology and Evolution, 8:141147.CrossRefGoogle ScholarPubMed
Goodman, M., Hide, W. A., and Li, W.-H. 1991. Is the guinea-pig a rodent? Nature, 351: 649652.Google Scholar
Gregory, W. K. 1910. The orders of mammals. Bulletin of the American Museum of Natural History, 27: 1524.Google Scholar
Hayasaka, K., Gojobori, T., and Horai, S. 1988. Molecular phylogeny and evolution of primate mitochondrial DNA. Molecular Biology and Evolution, 5: 626644.Google Scholar
Hunt, R. M., and Tedford, R. H. 1993. Phylogenetic relationships within the aeluroid Carnivora and implications of their temporal and geographic distribution, p. 5373. In Szalay, F. S., Novacek, M. J. and McKenna, M. C. (eds.), Mammal Phylogeny. Placentals. Springer Verlag, New York.Google Scholar
Irwin, D. M., Kocher, T. D., and Wilson, A. C. 1991. Evolution of the cytochrome b gene of mammals. Journal of Molecular Evolution, 32:128144.CrossRefGoogle ScholarPubMed
Janis, C. M., and Scott, K. M. 1988. The phylogeny of the Ruminantia (Artiodactyla, Mammalia), p. 273282. In Benton, M. J. (ed.), The Phylogeny and Classification of Tetrapods, Vol. 2. Clarendon Press, Oxford.Google Scholar
Jerison, H. J. 1973. Evolution of the Brain and Intelligence. Academic Press, New York.Google Scholar
Kirsch, J. A. W., and Johnson, J. 1983. Phylogeny through brain traits: Trees generated by neural characters. Brain, Behavior and Evolution, 22: 6069.Google Scholar
Kirsch, J. A. W., Dickerman, A.W., Reig, O. A., and Springer, M. S. 1991. DNA hybridization evidence for the Australasian affinity of the American marsupial Dromiciops australis . Proceedings of the National Academy of Science, 88:1046510469.Google Scholar
Kraus, F., and Miyamoto, M. M. 1991. Rapid cladogenesis among the pecoran ruminants: Evidence from mitochondrial DNA sequences. Systematic Zoology, 38: 725.Google Scholar
Krause, D., and Carlson, S. J. 1987. Prismatic enamel in multituberculate mammals: Tests of homology and polarity. Journal of Mammalogy, 68: 755765.CrossRefGoogle Scholar
Lucas, S. G. 1993. Pantodonts, tillodonts, uintatheres, and pyrotheres are not ungulates, p. 182194. In Szalay, F. S., Novacek, M. J. and McKenna, M. C. (eds.), Mammal Phylogeny. Placentals. Springer Verlag, New York.Google Scholar
Luckett, W. P. 1975. Ontogeny of the fetal membranes and placenta: Their bearing on primate phylogeny, p. 157182. In Luckett, W. P. and Szalay, F. S. (eds.), Phylogeny of the Primates. Plenum Press, New York.Google Scholar
Luckett, W. P. 1977. Ontogeny of amniote fetal membranes and their application to phylogeny, p. 439516. In Hecht, M. K., Goody, P.C., and Hecht, B. M. (eds.), Major Patterns in Vertebrate Evolution. Plenum Press, New York.CrossRefGoogle Scholar
Luckett, W. P. 1980. The suggested evolutionary relationships and classification of tree shrews, p. 331. In Luckett, W. P. (ed.), Comparative Biology and Evolutionary Relationships of Tree Shrews. Plenum Press, New York.Google Scholar
Luckett, W. P. 1985. Superordinal and intraordinal affinities of rodents: Developmental evidence from dentition and placentation, p. 227276. In Luckett, W. P. and Hartenberger, J.- L. (eds.), Evolutionary Relationships among Rodents. Plenum Press, New York.Google Scholar
Luckett, W. P., and Hartenberger, J.-L. 1993. Monophyly or polyphyly of the order Rodentia: Possible conflict between morphological and molecular interpretations. Journal of Mammalian Evolution, 1 (2): 127147.Google Scholar
MacPhee, R. D. E. in press. Morphology, adaptations, and relationships of Plesiorycteropus and a diagnosis of a new order of eutherian mammals. Bulletin, American Museum of Natural History,Google Scholar
MacPhee, R. D. E., and Novacek, M. J. 1993. Definition and relationships of Lipotyphla, p. 1331. In Szalay, F. S., Novacek, M. J. and McKenna, M. C. (eds.), Mammal Phylogeny. Placentals. Springer Verlag, New York.Google Scholar
Maier, W. 1987a. The ontogenetic development of the orbitotemporal region in the skull of Monodelphis domestica (Didelphidae, Marsupialia), and the problem of the mammalian alisphenoid, p. 7190. In Kuhn, H. J. and Zeller, U. (eds.), Morphogenesis of the Mammalian Skull. Mammalia Depicta, Heft 13.Google Scholar
Maier, W. 1987b. Der Processus angularis bei Monodelphis domestica (Didelphidae, Marsupialia) und seine Beziehungen zum Mittelohr: Eine ontogenetische and evolutionsmorphologische Untersuchung. Gegenbaurs Morphologisches Jahrbuch, 133:123161.Google Scholar
Maier, W. 1989. Morphologische Untersuchungen am Mittelohr der Marsupialia. Zeitschrift für Zoologie, Systematik, und Evolutionforschung, 27:149168.Google Scholar
Marshall, L.G., Case, J. A., and Woodburne, M. O. 1990. Phylogenetic relationships of the families of marsupials, p. 433505. In Genoways, H. H. (ed.), Current Mammalogy, Vol. 2. Plenum Press, New York.Google Scholar
McDowell, S. B. 1958. The Greater Antillean insectivores. Bulletin, American Museum of Natural History, 115: 113214.Google Scholar
McKenna, M. C. 1975. Toward a phylogenetic classification of the Mammalia, p. 2146. In Luckett, W. P. and Szalay, F. S. (eds.), Phylogeny of the Primates. Plenum Press, New York.Google Scholar
McKenna, M. C. 1987. Molecular and morphological analysis of higher level mammalian interrelationships, p. 5593. In Patterson, C. (ed.), Molecules and Morphology in Evolution: Conflict or Compromise? Cambridge University Pess, Cambridge.Google Scholar
McKenna, M. C. 1992. The alpha crystallin A chain of the eye lens and mammalian phylogeny. Annales Zoologici Fennici, 28: 349360.Google Scholar
Milinkovitch, M. C., Orti, G., and Meyer, A. 1993. Revised phylogeny of whales suggested by mitochondrial ribosomal DNA sequences. Nature, 361(6410): 346348.Google Scholar
Mindell, D. P., Dick, C. W., and Baker, R. J. 1991. Phylogenetic relationships among megabats, microbats, and primates. Proceedings of the National Academy of Science, 88: 1032210326.Google Scholar
Miyamoto, M. M., and Goodman, M. 1986. Biomolecular systematics of eutherian mammals: Phylogenetic patterns and classification. Systematic Zoology, 35: 230240.Google Scholar
Miyamoto, M. M., and Boyle, S. M. 1989. The potential importance of mitochondrial DNA sequence data to eutherian mammal phylogeny, p. 437452. In Fernholm, B., Bremer, K., and Jørnvall, H. (eds.), The Hierarchy of Life. Nobel Symposium 70. Elsevier Science Publishers, Amsterdam.Google Scholar
Mossman, H. W. 1937. Comparative morphogenesis of the fetal membranes and accessory uterine structures. Carnegie Institute, Contributions to Embryology, 26:129246.Google Scholar
Mossman, H. W. 1987. Vertebrate Fetal Membranes. Rutgers University Press, New Brunswick, New Jersey.Google Scholar
Nelson, G., and Platnick, N. 1981. Systematics and Biogeography: Cladistics and Vicariance. Columbia University Press, New York.Google Scholar
Norell, M. A., and Novacek, M. J. 1992a. The fossil record and evolution: Comparing cladistic and paleontologic evidence for vertebrate history. Science, 255: 16901693.Google Scholar
Norell, M. A., and Novacek, M. J. 1992b. Congruence between superpositional and phylogenetic patterns: Comparing cladistic patterns with fossil records. Cladistics, 8: 319337.CrossRefGoogle ScholarPubMed
Novacek, M. J. 1980. Cranioskeletal features in tupaiids and selected Eutheria as phylogenetic evidence, p. 3593. In Luckett, W. P. (ed.), Comparative Biology and Evolutionary Relationships of Tree Shrews. Plenum Press, New York.Google Scholar
Novacek, M. J. 1986. The skull of leptictid insectivorans and the higher-level classification of eutherian mammals. Bulletin, American Museum of Natural History, 183:1111.Google Scholar
Novacek, M. J. 1990. Morphology, paleontology, and the higher clades of mammals, p. 507543. In Genoways, H. H. (ed.), Current Mammalogy, Vol. 2. Plenum Press, NewYork.Google Scholar
Novacek, M. J. 1991. “All tree histograms” and the evaluation of cladistic evidence: some ambiguities. Cladistics, 7: 345349.Google Scholar
Novacek, M. J. 1992a. Mammalian phylogeny: shaking the tree. Nature, 356: 121125.Google Scholar
Novacek, M. J. 1992b. Fossils as critical data for phylogeny, p. 4688. In Novacek, M. J. and Wheeler, Q. D. (eds.), Extinction and Phylogeny. Columbia University Press, New York.Google Scholar
Novacek, M. J. 1992c. Fossils, topologies, missing data, and the higher level phylogeny of eutherian mammals. Systematic Biology, 41: 5873.Google Scholar
Novacek, M. J. 1993a. Reflections on higher mammalian phylogenetics. Journal of Mammalian Evolution, 1 (1): 330.Google Scholar
Novacek, M. J. 1993b. Patterns of diversity of the mammalian skull, p. 438545. In Hanken, J. and Hall, B. K. (eds.), The Vertebrate Skull, Vol. 2. University of Chicago Press, Chicago.Google Scholar
Novacek, M. J. In press. Morphological and molecular inroads to phytogeny, p. 85131. In Grande, L. and Rieppel, O.A. (eds.), Interpreting the Hierarchy of Life: From Systematic Patterns to Evolutionary Process Theories. Academic Press, Chicago.Google Scholar
Novacek, M. J., and Wyss, A. R. 1986. Higher-level relationships of the Recent eutherian orders: Morphological evidence. Cladistics, 2: 257287.CrossRefGoogle ScholarPubMed
Novacek, M. J., Wyss, A. R., and McKenna, M. C. 1988. The major groups of eutherian mammals, p. 3171. In Benton, M. J. (ed.), The Phytogeny and Classification of the Tetrapods, Vol. 2. Clarendon Press, Oxford.Google Scholar
Pettigrew, J. D. 1986. Flying primates? Megabats have the advanced pathway from eye to midbrain. Science, 231:13041306.Google Scholar
Pettigrew, J. D. 1991a. Wings or brain? Convergent evolution in the origins of bats. Systematic Zoology, 40: 199216.Google Scholar
Pettigrew, J. D. 1991b. A fruitful, wrong hypothesis? Response to Baker, Novacek, and Simmons. Systematic Zoology, 40: 231239.Google Scholar
Pettigrew, J. D., Jamieson, B. G. M., Robson, S. K., Hall, L. S., McAnally, K. I., and Cooler, H. M. 1989. Phylogenetic relations between microbats, megabats and primates (Mammalia: Chiroptera and Primates). Philosophical Transactions, Royal Society London, B. Biological Sciences, 325: 489559.Google Scholar
Prothero, D.R., Manning, E. M., and Fischer, M. 1988. The phytogeny of the ungulates, p. 201234. In Benton, M. J. (ed.), The Phytogeny and Classification of the Tetrapods, Vol. 2. Clarendon Press, Oxford.Google Scholar
Prothero, D.R., and Schoch, R.M. 1989. Origin and evolution of the Perissodactyla: Summary and synthesis, p. 504529. In Prothero, D.R. and Schoch, R.M. (eds.), The Evolution of Perissodactyls. Oxford University Pess, New York.Google Scholar
Rose, K. D., and Emry, R. J. 1993. Relationships of Xenarthra, Pholidota, and fossil “edentates”: The morphological evidence, p. 81102. In Szalay, F. S., Novacek, M. J., McKenna, M. C. (eds.), Mammal Phytogeny. Placentals. Springer Verlag, New York.Google Scholar
Sarich, W. M. 1969. Pinniped origins and the rate of evolution of carnivore albumins. Systematic Zoology, 18: 286295.CrossRefGoogle ScholarPubMed
Sarich, W. M. 1985. Rodent macromolecular systematics, p. 423452. In Luckett, W. P. and Hartenberger, J.-L. (eds.), Evolutionary Relationships among Rodents. Plenum Press, New York.Google Scholar
Shoshani, J. 1993. Hyracoidea-Tethytheria affinity based on myological data, p. 235256. In Szalay, F. S., Novacek, M. J., and McKenna, M. C. (eds.), Mammal Phytogeny. Placentals. Springer Verlag, New York.Google Scholar
Simmons, N. B., Novacek, M. J., and Baker, R. J. 1991. Approaches, methods, and the future of the chiropteran monophyly controversy: A reply to J. D. Pettigrew. Systematic Zoology, 40: 239243.Google Scholar
Simpson, G. G. 1945. The principles of classification and a classification of mammals. Bulletin, American Museum of Natural History, 85:1350.Google Scholar
Simpson, G. G. 1978. Early mammals in South America: Fact, controversy, and mystery. Proceedings, American Philosophical Society, 122: 318328.Google Scholar
Springer, M. S., and Kirsch, J. A. W. 1993. A molecular perspective on the phytogeny of placental mammals based on mitochondrial 12S rDNA sequences, with special reference to the problem of the Paenungulata. Journal of Mammalian Evolution, 1(2): 149166.Google Scholar
Stanhope, M.J., Czelusniak, J., Si, J. S., Nickerson, J., and Goodman, M. 1992. A molecular perspective on mammalian evolution from the gene encoding interphotoreceptor retinoid binding protein, with convincing evidence for bat monophyly. Molecular Phylogenetics and Evolution, 1(2): 148160.CrossRefGoogle ScholarPubMed
Szalay, F. S. 1977. Phylogenetic relationships and a classification of the eutherian Mammalia, p. 315374. In Hecht, M. K., Goody, P. C., and Hecht, B. M. (eds.), Major Patterns in Vertebrate Evolution. Plenum Press, New York.Google Scholar
Szalay, F. S. 1982. A new appraisal of marsupial phylogeny and a classification, p. 621640. In Archer, M. (ed.), Carnivorous Marsupials, Vol. 2. Royal Zoological Society, New South Wales.Google Scholar
Szalay, F. S., Novacek, M.J., and McKenna, M. C. (eds.), 1993. Mammal Phylogeny. 1: Mesozoic differentiation, multituberculates, monotremes, early therians, and marsupials, 249 p.; 2: Placentals, 321 p. Springer Verlag, New York.Google Scholar
Tandler, J. 1902. Zür Entwicklungsgeschichte der Kopfarterien bei den Mammalia. Gegenbaurs Morphologisches Jahrbuch, 30: 275373.Google Scholar
Tedford, R. H. 1976. Relationship of pinnipeds to other carnivores (Mammalia). Systematic Zoology, 25: 363374.Google Scholar
Thewissen, J. G., and Babcock, S. K. 1991. Distinctive cranial and cervical innervation of wing muscles: New evidence for bat monophyly. Science, 251:934936.Google Scholar
Thewissen, J. G., Hussain, S. T., and Aris, M. 1994. Fossil evidence for the origin of aquatic locomotion in archaeocete whales. Science, 263: 210212.Google Scholar
Thiele, A., Vogelsang, M., and Hoffmann, K.-P. 1991. Patterns of retinotectal projection in the megachiropteran bat Rousettus aegyptiacus . Journal of Comparative Neurology, 314: 671683.Google Scholar
Vrana, P., Milinkovitch, M.C., Powell, J.R., and Wheeler, W.C. 1994. Higher level relationships of the arctoid Carnivora based on sequence data and “total evidence.” Molecular Phylogenetics and Evolution, 3: 4758.Google Scholar
Westerman, M., and Edwards, D. 1991. The relationship of Dromiciops australis to other marsupials: Data from DNA-DNA hybridisation studies. Australian Journal of Zoology, 39:123130.Google Scholar
Wible, J. R. 1986. Transformation in the extracranial course of the internal carotid artery in mammalian phylogeny. Journal of Vertebrate Paleontology, 6: 313325.Google Scholar
Wible, J. R. 1987. The eutherian stapedial artery: character analysis and implications for superordinal relationships. Zoological Journal of the Linnaean Society, 91:107135.Google Scholar
Wible, J. R., and Novacek, M. J. 1988. Cranial evidence for the monophyletic origin of bats. American Museum Novitates, 2911:119.Google Scholar
Wyss, A. R. 1987. The walrus auditory region and the monophyly of pinnipeds. American Museum Novitates, 2871:131.Google Scholar
Wyss, A. R. 1989. Flippers and pinniped phylogeny: Has the problem of convergence been overrated? Marine Mammal Sciences, 5: 343360.Google Scholar
Wyss, A. R., Novacek, M.J., and McKenna, M.C. 1987. Amino acid sequence versus morphological data and the interordinal relationship of mammals. Molecular Biology and Evolution, 4: 99116.Google Scholar
Wyss, A. R., and Flynn, J. J. 1993. A phylogenetic analysis and definition of the Carnivora, p. 3252. In Szalay, F. S., Novacek, M. J. and McKenna, M. C. (eds.), Mammal Phylogeny. Placentals. Springer Verlag, New York.Google Scholar
Zeller, U. 1987. Morphogenesis of the mammalian skull with special reference to Tupaia , p. 1750. In Kuhn, H.-J. and Zeller, U. (eds.), Morphogenesis of the Mammalian Skull. Mammalia Depicta, Heft 13.Google Scholar
Zeller, U., Wible, J. R., and Elsner, M. 1993. New ontogenetic evidence on the septomaxilla of Tamandua and Choloepus (Mammalia, Xenarthra), with a reevaluation of the homology of the mammalian septomaxilla. Journal of Mammalian Evolution, 1 (1): 3146,Google Scholar
Zuckerkandl, E., and Pauling, L. 1962. Molecular disease, evolution and genic heterogeneity, p. 189225. In Kash, M. and Bullman, B. (eds.), Horizons in Biochemistry. Academic Press, New York.Google Scholar