Hostname: page-component-cd9895bd7-dk4vv Total loading time: 0 Render date: 2024-12-27T08:34:13.806Z Has data issue: false hasContentIssue false
  • English
  • Français

To replace or not to replace: the significance of reduced functional tooth replacement in marsupial and placental mammals

Published online by Cambridge University Press:  08 April 2016

Alexander F. H. van Nievelt  and
Kathleen K. Smith
Alexander F. H. van Nievelt
Affiliation:
Department of Biological Anthropology and Anatomy, Box 90383, Duke University, Durham, North Carolina 27708
Kathleen K. Smith
Affiliation:
Department of Biology, Box 90338, Duke University, Durham, North Carolina 27708. E-mail: [email protected]
Get access Rights & Permissions [Opens in a new window]

Abstract

Marsupial mammals are characterized by a pattern of dental replacement thought to be unique. The apparent primitive therian pattern is two functional generations of teeth at the incisor, canine, and premolar loci, and a series of molar teeth, which by definition are never replaced. In marsupials, the incisor, canine, and first and second premolar positions possess only a single functional generation. Recently this pattern of dental development has been hypothesized to be a synapomorphy of metatherians, and has been used to diagnose taxa in the fossil record. Further, the suppression of the first generation of teeth has been linked to the marsupial mode of reproduction, through the mechanical suppression of odontogenesis during the period of fixation of marsupials, and has been used to reconstruct the mode of reproduction of fossil organisms. Here we show that dental development occurs throughout the period of fixation; therefore, the hypothesis that odontogenesis is mechanically suppressed during this period is refuted. Further, we present comparative data on dental replacement in eutherians and demonstrate that suppression of tooth replacement is fairly common in diverse groups of placental mammals. We conclude that reproductive mode is neither a necessary nor a sufficient explanation for the loss of tooth replacement in marsupials. We explore possible alternative explanations for the loss of replacement in therians, but we argue that no single hypothesis is adequate to explain the full range of observed patterns.

Type
Articles
Information
Paleobiology , Volume 31 , Issue 2 , Spring 2005 , pp. 324 - 346
Copyright
Copyright © The 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

Literature Cited

Anthony, R. 1934. La dentition de l'oryctérope: morphologie, développement, structure, interpretation. Annales des Sciences Naturelles, Zoologie series 10 (tome 27):289–322.Google Scholar
Archer, M. 1978. The nature of the molar-premolar boundary in marsupials and a reinterpretation of the homology of marsupial cheekteeth. Memoirs of the Queensland Museum 18:157–164.Google Scholar
Asher, R. J. 2001. Cranial anatomy in tenrecid insectivorans: character evolution across competing phylogenies. American Museum of Natural History Novitates 3352:1–54.Google Scholar
Auerlich, R. J., and Swindler, D. R. 1968. The dentition of the mink (Mustela vison). Journal of Mammalogy 49:488–494.Google Scholar
Berkovitz, B. K. B. 1978. Tooth ontogeny in Didelphis virginiana. Australian Journal of Zoology 26:61–68.CrossRefGoogle Scholar
Berkovitz, B. K. B. 2000. Tooth replacement patterns in non-mammalian vertebrates. Pp. 186–200in Teaford, M. F., Smith, M. M., and Ferguson, M. W. J., eds. Development, function and evolution of teeth. Cambridge University Press, Cambridge.Google Scholar
Berkovitz, B. K. B., and Silverstone, L. M. 1969. The dentition of the albino ferret. Caries Research 3:369–376.CrossRefGoogle ScholarPubMed
Bloch, J., Rose, K. D., and Gingerich, P. D. 1998. New species of Batodonoides (Lipotyphla, Geolabididae) from the early Eocene of Wyoming: smallest known mammal? Journal of Mammalogy 79:804–827.Google Scholar
Brooks, P. M. 1972. Post-natal development of the African bush rat, Aethomys chrysophilus. Zoologica Africana 7:85–102.Google Scholar
Broom, R. 1909. On the milk dentition of Orycteropus. Annals of the South African Museum 5:381–384.Google Scholar
Cifelli, R. L., and de Muizon, C. 1998. Tooth eruption and replacement pattern in early marsupials. Comptes Rendus de l'Académie des Sciences, série II, Sciences de la Terre et des Planètes 326:215–220.Google Scholar
Cifelli, R. L., Rowe, T. B., Luckett, W. P., Banta, J., Reyes, R., and Howes, R. I. 1996. Fossil evidence for the origin of the marsupial pattern of tooth replacement. Nature 379:715–719.CrossRefGoogle Scholar
Czaplewski, N. J. 1987. Deciduous teeth of Thyroptera tricolor. Bat Research News 28:23–25.Google Scholar
Dittrich, L. 1960. Milchgebissentwicklung und Zahnwechsel beim Braunbaren (Ursus arctos L.) und anderen Ursiden. Morphologisches Jahrbuch 101:1–142.Google Scholar
Dorst, J. 1953. Note sur la dentition d'un foetus de Lavia frons (Chiroptères, Mégadermatidés). Mammalia 17:83–84.CrossRefGoogle Scholar
Dragoo, J. W., and Honeycutt, R. L. 1997. Systematics of mustelid-like carnivores. Journal of Mammalogy 78:426–443.Google Scholar
Eadie, W. R. 1944. Tooth replacement in Brewer's mole. Anatomical Record 89:357–360.Google Scholar
Eisenberg, J. F., and Redford, K. H. 1999. Mammals of the Neotropics, Vol. 1. The central neotropics. University of Chicago Press, Chicago.Google Scholar
Evans, H. E. 1993. Miller's anatomy of the dog. W. B. Saunders, Philadelphia.Google Scholar
Fairall, N. 1980. Growth and age determination in the hyrax Procavia capensis. South African Journal of Zoology 15:16–21.CrossRefGoogle Scholar
Fenton, M. B. 1970. The deciduous dentition and its replacement in Myotis lucifugus (Chiroptera: Vespertilionidae). Canadian Journal of Zoology 48:817–820.Google Scholar
Flower, W. H. 1867. On the development and succession of the teeth in the Marsupialia. Philosophical Transactions of the Royal Society of London 157:631–641, plates XXIX, XXX.Google Scholar
Flower, W. H. 1868. On the development and succession of teeth in the armadillos (Dasypodidae). Proceedings of the Zoological Society of London 1868:378–380.Google Scholar
Flynn, J. J., Nedbal, M. A., Dragoo, J. W., and Honeycutt, R. L. 2000. Whence the Red Panda? Molecular Phylogenetics and Evolution 17:190–199.Google Scholar
Gaunt, W. A. 1967. Observations upon the developing dentition of Hipposideros caffer (Microchiroptera). Acta Anatomica 68:9–25.CrossRefGoogle Scholar
Getty, R. 1975. The anatomy of the domestic animals. W. B. Saunders, Philadelphia.Google Scholar
Gilbert, A. N. 1995. Tenacious nipple attachment in rodents: the sibling competition hypothesis. Animal Behaviour 50:881–891.Google Scholar
Gompper, M. E. 1995. Nasua narica. Mammalian Species 487:1–10.Google Scholar
Gow, C. E. 1985. Apomorphies of the Mammalia. South African Journal of Science 81:558–560.Google Scholar
Grassé, P.-P. 1955. Traité de zoologie, Tome 17. Mammifères. Masson, Paris.Google Scholar
Guiler, E. R., and Heddle, R. W. L. 1974. The eruption and growth of teeth in the Tasmanian devil, Sarcophilus harrissi (Marsupialia: Dasyuridae). Papers and Proceedings of the Royal Society of Tasmania 108:137–140.Google Scholar
Habermehl, K. H., and Röttcher, D. 1967. Die Möglichkeiten der Altersbestimmung beim Marder und Iltis. Zeitschrift für Jagdwissenschaft 13:89–102.Google Scholar
Haltenorth, T. 1962. Die Wildkatze. A. Ziemsen, Wittenberg.Google Scholar
Hamilton, W. J. Jr. 1953. Reproduction and young of the Florida wood rat, Neotoma f. floridiana (Ord). Journal of Mammalogy 34:180–189.Google Scholar
Hanamura, H., Uematsu, Y., and Setoguchi, T. 1988. Replacement of the first premolars in Japanese shrew-moles (Talpidae: Insectivora). Journal of Mammalogy 69:135–138.Google Scholar
Heuser, P. 1913. Über die Entwicklung des Milchzahngebisses des afrikanischen Erdferkels (Orycteropus capensis Geoffr.). Ein Beitrag zur Histologic der Zahnentwicklung der Edentaten. Zeitschrift für wissenschaftliche Zoologie 104:622–691.Google Scholar
Hill, J. P., and Hill, W. C. O. 1955. The growth-stages of the pouch-young of the Native Cat (Dasyurus viverrinus) together with observations on the anatomy of the new-born young. Transactions of the Zoological Society of London 28:349–427.Google Scholar
Hill, J. P., and O'Donoghue, C. H. 1913. The reproductive cycle in the marsupial Dasyurus viverrinus. Quarterly Journal of Microscopical Science 59:133–174.Google Scholar
Hirschfeld, Z., Weinreb, M. M., and Michaeli, Y. 1973. Incisors of the rabbit: morphology, histology, and development. Journal of Dental Research 52:377–384.Google Scholar
Hopson, J. A. 1973. Endothermy, small size, and the origin of mammalian reproduction. American Naturalist 107:446–452.Google Scholar
Humason, G. L. 1979. Animal tissue techniques, 4th ed.W. H. Freeman, San Francisco.Google Scholar
Ivanco, T. L., Pellis, S. M., and Whishaw, I. Q. 1996. Skilled fore-limb movements in prey catching and in reaching by rats (Rattus norvegicus) and opossums (Monodelphis domestica): relations to anatomical differences in motor systems. Behavioural Brain Research 79:163–181.Google Scholar
Kainer, R. A. 1954. The gross anatomy of the digestive system of the mink. I. The headgut and the foregut. American Journal of Veterinary Research 15:82–90.Google Scholar
Kenyon, K. B. 1969. The sea otter in the eastern Pacific Ocean. North American Fauna 68:1–352.Google Scholar
Kindahl, M. 1957. On the development of the tooth in Tupaia javanica. Arkiv för Zoologi 10:463–479.Google Scholar
Kindahl, M. 1959a. Some aspects of the tooth development in the Soricidae. Acta Odontologica Scandinavica 17:203–237.Google Scholar
Kindahl, M. 1959b. The tooth development in Erinaceus europaeus. Acta Odontologica Scandinavica 17:467–489.Google Scholar
King, J. E. 1983. Seals of the world. British Museum (Natural History), London.Google Scholar
Kirkpatrick, R. D., and Sowls, L. K. 1962. Age determination of the collared peccary by the tooth-replacement pattern. Journal of Wildlife Management 26:214–217.Google Scholar
Kirkpatrick, T. H. 1978. The development of the dentition of Macropus giganteus (Shaw): an attempt to interpret the marsupial dentition. Australian Mammalogy 2:29–35.Google Scholar
Koyasu, K., and Mukohyama, M. 1992. Dental morphology of deciduous teeth in the bat, Vespertilio orientalis. Pp. 115–123in Smith, P. and Tchernov, E., eds. Structure, function and evolution of teeth. Freund, London.Google Scholar
Kozawa, Y., Iwasa, Y., and Mishima, H. 1998. Degeneration of tooth germ in the developing dentition of the gray short-tailed opossum (Monodelphis domestica). European Journal of Oral Sciences 106(Suppl. 1):509–512.Google Scholar
Kubota, K., Shibanai, S., Kubota, J., and Togawa, S. 2000. Developmental transition to monophyodonty in adaptation to marine life by the northern fur seal, Callorhinus ursinus (Otariidae). Historical Biology 14:91–95.CrossRefGoogle Scholar
Kükenthal, W. 1891. Das Gebiß von Didelphys. Anatomischer Anzeiger 6:658–666.Google Scholar
Lawrence, B. 1941. Incisor tips of young rodents. Field Museum of Natural History Zoological Series 27:313–317.Google Scholar
Laws, R. M. 1953. The elephant seal (Mirounga leonina Linn.) I. Growth and age. Falkland Islands Dependencies Survey Scientific Reports 8:1–62.Google Scholar
Leche, W. 1895. Zur Entwicklungsgeschichte des Zahnsystems der Säugethiere zugleich ein Beitrag zur Stammesgeschichte dieser Thiergruppe. Erwin Nägele, Stuttgart.Google Scholar
Leche, W. 1897. Zur Morphologie des Zahnsystems der Insectivoren. I. u. II. Anatomischer Anzeiger 13:1–11, 513–529.Google Scholar
Leche, W. 1902. Zur Entwicklungsgeschichte des Zahnsystems der Säugethiere II. Phylogenie 1.H. Die Familie der Erinaceidae. Zoologica, Stuttgart 37:1–103.Google Scholar
Leche, W. 1904. Über Zahnwechsel bei Säugetiere im erwachsenen Zustande. Zoologischer Anzeiger 27:219–222.Google Scholar
Leche, W. 1907. Zur Entwicklungsgeschichte des Zahnsystems der Säugetiere II. Phylogenie 2. Die Familien der Centetidae, Solenodontidae und Chrysochloridae. Zoologica, Stuttgart 49:1–158.Google Scholar
Leche, W. 1915. Zur Frage nach der stammesgeschichtlichen Bedeutung des Milchgebisses bei den Säugetieren II. Viverridae, Hyaenidae, Felidae, Mustelidae, Creodonta. Zoologische Jahrbücher. Abteilung für Systematik, Geographie, und Biologie der Tiere 38:275–370.Google Scholar
Linhart, S. B. 1968. Dentition and pelage in the juvenile red fox (Vulpes vulpes). Journal of Mammalogy 49:526–528.Google Scholar
Lombaard, L. J. 1971. Age determination and growth curves in the black-backed jackal, Canis mesomelas Schreber, 1775 (Carnivora: Canidae). Annals of the Transvaal Museum 27:135–169.Google Scholar
Long, C. A. 1965. Comparison of juvenile skulls of the mustelid genera Taxidea and Meles, with comments on the taxon Taxidiinae Pocock. American Midland Naturalist 74:225–232.Google Scholar
Long, C. A. 1974. Growth and development of the teeth and skull of the wild North American badger, Taxidea taxus. Transactions of the Kansas Academy of Science 77:106–120.Google Scholar
Luckett, W. P. 1989. Developmental evidence for dental homologies in the marsupial family Dasyuridae. Anatomical Record 223:70A.Google Scholar
Luckett, W. P. 1993. An ontogenetic assessment of dental homologies in therian mammals. Pp. 182–204in Szalay, F. S., Novacek, M. J., and McKenna, M. C., eds. Mammal phylogeny, Vol. 1. Mesozoic differentiation, multituberculates, monotremes, early therians, and marsupials. Springer, New York.Google Scholar
Luckett, W. P., and Hong, N. 2000. Ontogenetic evidence for dental homologies and premolar replacement in fossil and extant caenolestids (Marsupialia). Journal of Mammalian Evolution 7:109–127.Google Scholar
Luckett, W. P., and Maier, W. 1982. Development of deciduous and permanent dentition in Tarsius and its phylogenetic significance. Folia Primatologica 37:1–36.Google Scholar
Luckett, W. P., and Woolley, P. A. 1996. Ontogeny and homology of the dentition in dasyurid marsupials: development in Sminthopsis virginiae. Journal of Mammalian Evolution 3:327–364.Google Scholar
MacDonald, D. W., ed. 1984. The encyclopedia of mammals. Facts on File, New York.Google Scholar
Malia, M. J., Adkins, R. M., and Allard, M. W. 2002. Molecular support for Afrotheria and the polyphyly of Lipotyphla based on analyses of the growth hormone receptor gene. Molecular Phylogenetics and Evolution 24:91–101.Google Scholar
Martin, B. E. 1916. Tooth development in Dasypus novemcinctus. Journal of Morphology 27:647–691.Google Scholar
Martin, T. 1997. Tooth replacement in late Jurassic Dryolestidae (Eupantotheria, Mammalia). Journal of Mammalian Evolution 4:1–18.Google Scholar
McCrady, E. Jr. 1938. The embryology of the opossum. Wistar Institute of Anatomy, Philadelphia.Google Scholar
Michaeli, Y., Hirschfeld, Z., and Weinreb, M. M. 1980. The cheek teeth of the rabbit: morphology, histology and development. Acta Anatomica 106:223–239.Google Scholar
Mísek, I., and Sterba, O. 1989. Developmental anatomy of the mole, Talpa europaea. X. Development of the dentition. Folia Zoologica 38:59–67.Google Scholar
Mitchell, O. G., and Carsen, C. A. 1967. Tooth eruption in the Arctic ground squirrel. Journal of Mammalogy 48:472–474.Google Scholar
Montgomery, G. G. 1964. Tooth eruption in preweaned raccoons. Journal of Wildlife Management 28:582–584.Google Scholar
Moshonkin, N. N. 1979. Formation of the dental system in the mink Lutreola lutreola. Zoologicheskii Zhurnal 58:1753–1756.Google Scholar
Moss-Salentijn, L. 1978. Vestigial teeth in the rabbit, rat and mouse: their relationship to the problem of lacteal dentitions. Pp. 13–29in Butler, P. M. and Joysey, K. A., eds. Development, function and evolution of teeth. Academic Press, London.Google Scholar
Muizon, , de, C. 1994. A new carnivorous marsupial from the Palaeocene of Bolivia and the problem of marsupial monophyly. Nature 370:208–211.Google Scholar
Neal, E. 1986. The natural history of badgers. Facts on File, New York.Google Scholar
Nikaido, M., Kawai, K., Cao, Y., Harada, M., Tomita, S., Okada, N., and Hasegawa, M. 2001. Maximum likelihood analysis of the complete mitochondrial genomes of eutherians and a reevaluation of the phylogeny of bats and insectivores. Journal of Molecular Evolution 53:508–516.Google Scholar
Nowak, R. M. 1999. Walker's mammals of the world. Johns Hopkins University Press, Baltimore.Google Scholar
Orr, R. T. 1954. Natural history of the pallid bat (Antrozous pallidus). Proceedings of the California Academy of Sciences 28:165–246.Google Scholar
Osborn, J. W., ed. 1981. Dental anatomy and embryology. Blackwell Scientific, Oxford.Google Scholar
Petrides, G. A. 1949. Sex and age determination in the opossum. Journal of Mammalogy 30:364–378.Google Scholar
Phillips, C. J. 1971. The dentition of glossophagine bats: development, morphological characteristics, variation, pathology, and evolution. University of Kansas Museum of Natural History, Miscellaneous Publications 54:1–138.Google Scholar
Phillips, C. J. 2000. A theoretical consideration of dental morphology, ontogeny, and evolution in bats. Pp. 247–274in Adams, R. A. and Pedersen, S. C., eds. Ontogeny, functional ecology, and evolution of bats. Cambridge University Press, Cambridge.Google Scholar
Poglayen-Neuwall, I. 1962. Beiträge zu einem Ethogramm des Wickelbären (Potos flavus Schreber). Zeitschrift für Säugetierkunde 27:1–44.Google Scholar
Poglayen-Neuwall, I. 1976. Zur Fortpflanzungsbiologie und Jugendentwicklung von Potos flavus (Schreber 1774). Zoologische Garten 46:237–283.Google Scholar
Poglayen-Neuwall, I. 1995. Developmental data on Bassariscus sumichrasti (Carnivora: Procyonidae). Zoologische Garten 65:391–396.Google Scholar
Poglayen-Neuwall, I., and Poglayen-Neuwall, I. 1976. Postnatal development of tayras, Eira barbara, in captivity. Zoologische Beiträge 22:345–405.Google Scholar
Poglayen-Neuwall, I., and Poglayen-Neuwall, I. 1993. Behavior, reproduction, and postnatal development of Bassariscus astutus (Carnivora; Procyonidae) in captivity. Zoologische Garten 63:73–125.Google Scholar
Reynolds, H. C. 1952. Studies on reproduction in the opossum (Didelphis virginiana). University of California Publications in Zoology 52:223–284.Google Scholar
Röse, C. 1892. Über die Zahnentwickelung der Beuteltiere. Anatomischer Anzeiger 7:639–650, 693–707.Google Scholar
Rougier, G. W., Wible, J. R., and Novacek, M. J. 1998. Implications of Deltatheridium specimens for early marsupial history. Nature 396:459–463.Google Scholar
Scheffer, V. B. 1951. Measurements of sea otters from western Alaska. Journal of Mammalogy 32:10–14.Google Scholar
Schneider, K. B. 1973. Age determination of sea otter. Alaska Department of Fish and Game, Final Report, Federal Aid in Wildlife Restoration, Projects W-17–4 and W-l7–5, Job 8.10R:1–23.Google Scholar
Slaughter, B. H. 1970. Evolutionary trends of chiropteran dentitions. Pp. 51–83in Slaughter, B. H. and Walton, W. D., eds. About bats. Southern Methodist University Press, Dallas.Google Scholar
Smith, B. H., Crummett, T. L., and Brant, K. L. 1994. Ages of eruption of primate teeth: a compendium for aging individuals and comparing life histories. Yearbook of Physical Anthropology 37:177–231.Google Scholar
Smith, K. K. 2001. The evolution of mammalian development. Bulletin of the Museum of Comparative Zoology 156:119–135.Google Scholar
Stangl, F. B. Jr., Beauchamp, S. L., and Konermann, N. G. 1995. Cranial and dental variation in the 9-banded armadillo, Dasypus novemcinctus, from Texas and Oklahoma. Texas Journal of Science 47:89–100.Google Scholar
Streilein, K. E. 1982. Behavior, ecology, and distribution of South American marsupials. Special Publication of the Pymatuning Laboratory of Ecology 6:231–250.Google Scholar
Thomas, O. 1887. On the homologies and succession of the teeth in the Dasyuridae, with an attempt to trace the history of the evolution of mammalian teeth in general. Philosophical Transactions of the Royal Society of London B 178:443–462.Google Scholar
Thomas, O. 1890. A milk dentition in Orycteropus. Proceedings of the Royal Society of London 47:246–248.Google Scholar
Thomas, O. 1911. The Duke of Bedford's zoological exploration of eastern Asia. XIII. On mammals from the provinces of Kansu and Sze-chwan, western China. Proceedings of the Zoological Society of London 1911:158–180.Google Scholar
Uhen, M. D. 2000. Replacement of deciduous first premolars and dental eruption in archaeocete whales. Journal of Mammalogy 81:123–133.Google Scholar
van der Merwe, M. 2000. Tooth succession in the greater cane rat Thryonomys swinderianus (Temminck, 1827). Journal of Zoology 251:541–545.Google Scholar
van Nievelt, A. F. H., and Smith, K. K. 2005. Tooth eruption in Monodelphis domestica and its significance for phylogeny and natural history. Journal of Mammalogy 86(2) (in press).Google Scholar
van Nostrand, F. C., and Stephenson, A. B. 1964. Age determination for beavers by tooth development. Journal of Wildlife Management 28:430–434.Google Scholar
VandeBerg, J. L. 1999. The laboratory opossum, Monodelphis domestica. Pp. 193–209in Poole, T. B., ed. UFAW handbook on the care and management of laboratory animals. Blackwell Science, Oxford.Google Scholar
Vaughan, T. A. 1970. The skeletal system. Pp. 97–138in Wimsatt, W. A., ed. Biology of bats. Academic Press, New York.Google Scholar
Verts, B. J. 1967. The biology of the striped skunk. University of Illinois Press, Urbana.Google Scholar
Whidden, H. P. 2000. Comparative myology of moles and the phylogeny of the Talpidae (Mammalia, Lipotyphla). American Museum of Natural History Novitates 3294:1–53.Google Scholar
Wilson, J. T., and Hill, J. P. 1897. Observations upon the development and succession of the teeth in Perameles; together with a contribution to the discussion of the homologies of the teeth in marsupial animals. Quarterly Journal of Microscopical Science 39:427–588, 8 plates.Google Scholar
Winge, H. 1941. The interrelationships of the mammalian genera, Vol. 1. C. A. Reitzel, Copenhagen.Google Scholar
Woodward, M. F. 1894. On the milk dentition of the Rodentia, with a description of a vestigial incisor in the mouse (Mus musculus). Anatomischer Anzeiger 9:619–631.Google Scholar
Wright, J. 1983. Biological significance of mammalian milk teeth. Ph.D. dissertation. Cornell University, Ithaca, N.Y.Google Scholar
Yates, T. L., and Moore, D. W. 1990. Speciation and evolution in the family Talpidae (Mammalia: Insectivora). Pp. 1–22in Nevo, E. and Reig, O. A., eds. Evolution of subterranean mammals at the organismal and molecular levels. Wiley-Liss, New York.Google Scholar
Zhang, F.-K., Crompton, A. W., Luo, Z.-X., and Schaff, C. R. 1998. Pattern of dental replacement of Sinoconodon and its implications for evolution of mammals. Vertebrata PalAsiatica 36:197–217.Google Scholar
Ziegler, A. C. 1971a. Dental homologies and possible relationships of recent Talpidae. Journal of Mammalogy 52:50–68.Google Scholar
Ziegler, A. C. 1971b. A theory of the evolution of therian dental formulas and replacement patterns. Quarterly Review of Biology 46:226–249.Google Scholar
Ziegler, A. C. 1972. Milk dentition in the broad-footed mole, Scapanus latimanus. Journal of Mammalogy 53:354–355.Google Scholar