Enamel Structure of Early Mammals and Its Role in Evaluating Relationships among Rodents

  • Ashok Sahni
Conference paper
Part of the NATO Advanced Science Institutes (ASI) Series book series (NSSA, volume 92)


The evolution of mammalian enamels is a matter of multidisciplinary interest, and in recent years considerable attention has been paid to the subject (Grine, 1978; Fosse et al., 1973; Sahni, 1979). Work has concentrated on studying Recent reptilian and mammalian enamels (Cooper and Poole, 1973; Poole, 1957; Boyde, 1966), while other studies have centered on the micro- and ultrastructure of various “ancestral” groups such as the therapsid (mammal-like) reptiles in the hope of documenting evidence of the change from the thin, nonprismatic structure of reptilian enamels to the thicker, prismatic enamels of mammals (Poole, 1956; Moss, 1969; Osborn and Hillman, 1979). The enamels of various fossil and Recent rodents have invited special attention since the classic work of Tomes (1850). Rodent enamels are the most complex and highly organized within Mammalia. There are distinct subordinal variations among various groups; material from both fossil and Recent rodents is readily available and, furthermore, the process of amelogenesis (enamel secretion) can be observed throughout the life history of an individual because of the phenomenon of evergrowing incisors (Korvenkontio, 1934; Kiel, 1966).


Tooth Enamel Enamel Structure Early Mammal Agamid Lizard Radial Enamel 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Boyde, A. 1964. The structure and development of mammalian enamel. Unpublished Ph. D. Thesis, Univ. of London, London.Google Scholar
  2. Boyde, A. 1966. The development of enamel structure in mammals. In: Third European Symposium on Calcified Tissues, H. J. J. Blackwood and M. Owen, eds., pp. 276–280, Springer, Berlin.Google Scholar
  3. Boyde, A. 1969a. Electron microscopic observations relating to the nature and development of prism decussation in mammalian dental enamel. Bull. Group Int. Rech. Sci. Stomat. 12: 151–207.Google Scholar
  4. Boyde, A. 1969b. Correlation of ameloblast size with enamel prism pattern: use of scanning electron microscope to make surface area measurements. Z. Zellforsch. 93: 583–593.PubMedCrossRefGoogle Scholar
  5. Boyde, A. and Lester, K. S. 1967. The structure and development of marsupial enamel tubules. Z. Zellforsch. 82: 558–576.PubMedCrossRefGoogle Scholar
  6. Boyde, A. and Martin, L. 1984. A non-destructive survey of enamel prism packing pattern in primate enamel. In: Tooth Enamel Symposium IV, Odawara, Japan, R. W. Fearnhead, ed., preprint pp. 1-4.Google Scholar
  7. Carlson, S. J. and Krause, D. W. 1982. Multituberculate phylogeny: Evidence from the tooth enamel ultrastructure. Abst. Geol. Soc. Amer. 2119: 460.Google Scholar
  8. Cooper, J. S. and Poole, D. F. G. 1973. The dentition and dental tissues of the agamid lizard, Uromastyx. J. Zool. 169: 85–100.CrossRefGoogle Scholar
  9. Emry, R. J. and Thorington, R. W. 1982. Descriptive and comparative osteology of the oldest fossil squirrel, Protosciurus (Rodentia: Sciuridae). Smithsonian Contrib. Paleobiol. 47: 1–35.CrossRefGoogle Scholar
  10. Fosse, G., Eskidsen, O., Risnes, S. and Sloan, R. E. 1978. Prism size in tooth enamel of some Late Cretaceous mammals and its value in multituberculate taxonomy. Zool. Scripta 7: 57–61.CrossRefGoogle Scholar
  11. Fosse, G., Risnes, S. and Holmbakken, M. 1973. Prisms and tubules in multituberculate enamel. Cal. Tiss. Res. 11: 133–150.CrossRefGoogle Scholar
  12. Frank, R. M., Sigogneau-Russell, D. and Vogel, J. C. 1984. Tooth ultrastructure of Late Triassic Haramiyidae. J. Dent. Res. 63: 661–664.PubMedCrossRefGoogle Scholar
  13. Grine, F. E. 1978. Postcanine dental structure in mammal-like reptile Diademodon (Therapsida: Cynodonta). Proc. Electron Micr. Soc. S. Afr. 8: 123–124.Google Scholar
  14. Grine, F. E. and Cruikshank, A. R. I. 1978. Scanning electron microscope analysis of postcanine tooth structure in the Late Triassic mammal Eozostrodon (Eotheria: Triconodonta). Proc. Electron Micr. Soc. S. Afr. 8: 121–122.Google Scholar
  15. Grine, F. E., Gow, C. E. and Kitching, J. W. 1979. Enamel structure in the cynodonts. Proc. Electron Micr. Soc. S. Afr. 9: 99–100.Google Scholar
  16. Hartenberger, J.-L. 1982. A review of the Eocene rodents of Pakistan. Contrib. Mus. Paleont. Univ. Mich. 26: 19–35.Google Scholar
  17. Hussain, S. T., De Bruijn, H. and Leinders, J. M. 1978. Middle Eocene rodents from the Kala Chitta Range (Punjab, Pakistan). Proc. Kon. Ned. Akad. Wet., Amsterdam, ser. B, 81: 74–112.Google Scholar
  18. Ishiyama, M. 1984. Comparative histology of tooth enamel in several toothed whales. In: Tooth Enamel Symposium IV, Odawara, Japan, R. W. Fearnhead, ed., preprint pp. 1-4.Google Scholar
  19. Kiel, A. 1966. Grundzüge der Odontologie. Gebrüder Bornträger, Berlin.Google Scholar
  20. Kielan-Jaworowska, Z. 1980. Absence of ptilodontoidean multituberculates from Asia and its palaeogeographic significance. Lethaia 13: 169–173.CrossRefGoogle Scholar
  21. Koenigswald, W. v. 1980. Schmelzstruktur und Morphologie in den Molaren der Arvicolidae (Rodentia). Abh. Senckenb. Naturforsch. Ges. 539: 1–129.Google Scholar
  22. Koenigswald, W. v. 1982a. Zum Verständnis der Morphologie der Wühlmausmolaren (Arvicolidae, Rodentia, Mammalia). Z. Geol. Wiss. Berlin 10: 951–962.Google Scholar
  23. Koenigswald, W. v. 1982b. Enamel structure in the molars of Arvicolidae (Rodentia, Mammalia), a key to functional morphology and phylogeny. In: Teeth: Form, Function, and Evolution, B. Kurten, ed., pp. 109–122, Columbia Univ. Press, New York.Google Scholar
  24. Korvenkontio, V. A. 1934. Mikroskopische Untersuchungen an Nagerincisiven unter Hinweis auf die Schmelzstruktur der Backenzähne. Ann. Zool. Soc. Zool.-Bot. Fenn. Vanamo 2: 1–274.Google Scholar
  25. Kozawa, Y. 1984. The development and evolution of mammalian enamel structure. In: Tooth Enamel Symposium IV, Odawara, Japan, R. W. Fearnhead, ed., preprint pp. 1-5.Google Scholar
  26. Kozawa, Y., Tateishi, M., Akaishi, S. and Hirail, G. 1981. The fine projection of Tomes process in the pig ameloblast by electron microscopy. J. Oral Sci. Nihon Univ. 7: 223–228.Google Scholar
  27. Kumar, K. 1983. Paleontological and paleohistological investigations of Subathu vertebrates from Jammu and Kashmir and Himachal Pradesh. Unpublished Ph. D. Thesis, Panjab Univ., Chandigarh.Google Scholar
  28. Moss, M. L. 1969. Evolution of mammalian dental enamel. Amer. Mus. Novit. 2360: 1–39.Google Scholar
  29. Moss, M. L. and Kermack, K. A. 1967. Enamel structure in two Upper Triassic mammals. J. Dent. Res. 46: 745–747.PubMedCrossRefGoogle Scholar
  30. Osborn, J. W. and Hillman, J. 1979. Enamel structure in some therapsids and Mesozoic mammals. Cal. Tiss. Int. 29: 47–61.CrossRefGoogle Scholar
  31. Poole, D. F. G. 1956. The structure of the teeth of some mammal-like reptiles. Quart. J. Micr. Sci. 97: 303–312.Google Scholar
  32. Poole, D. F. G. 1957. The formation and properties of the organic matrix of reptilian tooth enamel. Quart. J. Micr. Sci. 98: 349–367.Google Scholar
  33. Poole, D. F. G. 1967. Enamel structure in primitive mammals. J. Dent. Res. 46: 124.Google Scholar
  34. Poole, D. F. G. 1971. An introduction into the phylogeny of calcified tissues. In: Dental Morphology and Evolution, A. Dahlberg, ed., Univ. of Chicago Press, Chicago.Google Scholar
  35. Sahni, A. 1979. Enamel structure of certain North American Cretaceous mammals. Palaeontographica A, 166: 37–49.Google Scholar
  36. Sahni, A. 1980. SEM studies of Indian Eocene and Siwalik rodent enamels. Geosci. J. 1: 21–30.Google Scholar
  37. Sahni, A. 1981. Ultrastructure of fossil Mammalia: Eocene Archaeoceti from Kutch. J. Paleont. Soc. India 25: 33–37.Google Scholar
  38. Schmidt, W. J. and Keil, A. 1971. Polarization Microscopy of Dental Tissue. Pergamon Press, Oxford.Google Scholar
  39. Tomes, J. 1850. On the structure of the dental tissues of the order Rodentia. Phil. Trans. Roy. Soc. Lond. 1850: 529–567.Google Scholar
  40. Van Valen, L. and Sloan, R. E. 1966. The extinction of the multituberculates. Syst. Zool. 15: 261–278.CrossRefGoogle Scholar
  41. Wahlert, J. H. 1968. Variability of rodent incisor enamel as viewed in thin section, and the microstructure of the enamel in fossil and recent rodent groups. Breviora, Mus. Comp. Zool. 309: 1–18.Google Scholar
  42. Wilson, R. W. 1972. Evolution and extinction in Early Tertiary rodents. Proc. 24th Int. Geol. Cong. Montreal 7: 217–224.Google Scholar
  43. Wood, A. E. 1980. The Oligocene rodents of North America. Trans. Amer. Philos. Soc. 70: 1–68.CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 1985

Authors and Affiliations

  • Ashok Sahni
    • 1
  1. 1.Centre of Advanced Study in GeologyPanjab UniversityChandigarhIndia

Personalised recommendations