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Mastication in the hyrax and its relevance to ungulate dental evolution

Published online by Cambridge University Press:  08 February 2016

Christine M. Janis
Christine M. Janis*
Affiliation:
Museum of Comparative Zoology, Harvard University, Cambridge, Massachusetts 02138
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Abstract

The hyrax, a living primitive subungulate, makes an ideal model in terms of its molar morphology for early lophodont ungulates. Cine fluoroscopic studies of mastication show that the proposed Phase II in jaw movement, experimentally demonstrated in primates, but surmised in ungulates only from molar wear facets, does in fact exist in this animal, but does not appear to be an important component of the masticatory cycle. Comparison of tooth wear in early Tertiary ungulates with contemporaneous primates shows that, whereas primates enlarge the Phase II wear facets on the molars as they move into more herbivorous niches, the same is not true for ungulates, and in fact Phase II may be lost altogether in grazing forms. It is concluded that “grinding” in herbivorous ungulates is a process fundamentally different from that described for herbivorous primates.

Type
Research Article
Information
Paleobiology , Volume 5 , Issue 1 , Winter 1979 , pp. 50 - 59
Copyright
Copyright © The Paleontological Society 

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References

Literature Cited

Butler, P. M. 1952. The milk molars of Perissodactyla, with remarks on molar occlusion. Proc. Zool. Soc. London. 121:777–817.CrossRefGoogle Scholar
Butler, P. M. 1972. Some functional aspects of molar evolution. Evolution. 26:474–483.CrossRefGoogle ScholarPubMed
Butler, P. M. 1973. Molar wear facets of early Tertiary North American primates. Pp. 1–27. Symp. IVth. Int. Congr. Primatol. Vol. 3. Craniofacial Biology of Primates. Karger; Basel.Google Scholar
Carlson, D. S. 1977. Condylar translation and the function of the superficial masseter muscle in the Rhesus monkey (M. mulatto). Am. J. Phys. Anthropol. 47:53–64.CrossRefGoogle Scholar
Crompton, A. W. 1963a. On the lower jaw of Diarthrognathus and the origin of the mammalian lower jaw. Proc. Zool. Soc. London. 140(4):697–753.CrossRefGoogle Scholar
Crompton, A. W. 1968. Studying function by X-ray. Discovery, New Haven, Conn. 3:50–51.Google Scholar
Crompton, A. W. 1971. The origin of the tribosphenic molar. In: Kermack, D. M. and Kermack, K. A., eds. Early Mammals. J. Linn. Soc. London. (Zool.) Suppl. 1:65–87.Google Scholar
Crompton, A. W. and Hiiemae, K. 1969. How mammalian molar teeth work. Discovery. 5(1):23–34.Google Scholar
Crompton, A. W. and Hiiemae, K. M. 1970. Functional occlusion and mandibular movements during occlusion in the American opossum, Didelphis marsupialis L. Zool. J. Linn. Soc. 49:21–47.CrossRefGoogle Scholar
Grzimek, B. 1974. Animal Life Encyclopedia. Vol. 13 (Mammals IV). 566 pp. Van Nostrand Reinhold Co.; New York.Google Scholar
Herring, S. W. 1975. Adaptations for gape in the hippopotamus and its relatives. Forma et Functio. 8:85–100.Google Scholar
Herring, S. W. and Herring, S. E. 1974. The superficial masseter and gape in mammals. Am. Nat. 108:561–576.CrossRefGoogle Scholar
Hiiemae, K. M. 1976. Masticatory movements in primitive mammals. Pp. 105–118. In: Anderson, D. J. and Matthews, B., eds. Mastication. John Wright & Sons, Ltd.; Bristol.Google Scholar
Hiiemae, K. M. 1978. Mammalian mastication: a review of the activity of jaw muscles and the movements they produce in chewing. Pp. 359–398. In: Butler, P. M. and Joysey, K., eds. Development, Structure and Function of the Teeth. Academic Press; London.Google Scholar
Hiiemae, K. M. and Jenkins, F. A. Jr. 1969. The anatomy and internal architecture of the muscles of mastication in Didelphis marsupialis. Postilla. 140:1–49.Google Scholar
Hoeck, H. 1975. Differential feeding behaviour of the sympatric hyrax Procavia johnstoni and Heterohyrax brucei. Oecologia (Berl.). 22:15–47.CrossRefGoogle ScholarPubMed
Janis, C. M.(in prep. a)The evolution of herbivorous dentition in primates and ungulates and the functional difference between selenodont and lophodont molars.Google Scholar
Janis, C. M.(in preb.b). Food processing in horses and ruminant artiodactyls and its relation to skull and molar morphology.Google Scholar
Kay, R. F. 1977. The evolution of molar occlusion in the Cercopithecidae and early catarrhines. Am. J. Phys. Anthropol. 46(2):327–352.CrossRefGoogle ScholarPubMed
Kay, R. F. and Hiiemae, K. M. 1977a. Jaw movements and tooth use in Recent and fossil primates. Am. J. Phys. Anthropol. 40:227–256.CrossRefGoogle Scholar
Kay, R. F. and Hiiemae, K. M. 1974b. Mastication in Galago crassicaudatus: a cine-fluorographic and occlusal study. Pp. 501–530. In: Martin, R. D., Doyle, G. A., and Walker, A. C., eds. Prosimian Biology. Duckworths; London.Google Scholar
Maynard Smith, J. and Savage, J. R. G. 1959. The mechanics of mammalian jaws. School Science Review. 141:289–302.Google Scholar
Mendelssohn, H. 1965. Breeding the Syrian Hyrax. Int. Zoo. Yearb. 5:116–125.CrossRefGoogle Scholar
Mills, J. R. E. 1963. Occlusion and malocclusion in the teeth of primates. Pp. 29–51. In: Brotherwell, D. R., ed. Dental Anthropology. Pergamon Press; Oxford.CrossRefGoogle Scholar
Radinsky, L. B. 1969. The early evolution of the Perissodactyla. Evolution 23(2):308–328.CrossRefGoogle Scholar
Romer, A. 1966. Vertebrate Paleontology. 3rd ed.446 pp. Univ. Chicago Press; Chicago.Google Scholar
Sale, J. B. 1960. The Hyracoidea. J. East Afr. Nat. Hist. Soc. 23(5):185–188.Google Scholar
Simpson, G. G. 1950. Horses. 247 pp. Oxford Univ. Press; Oxford.Google Scholar
Turnbull, W. D. 1970. Mammalian masticatory apparatus. Fieldiana, Geology. 18(2):149–356.Google Scholar