A plant-eating crocodyliform reptile from the Cretaceous of China
Xiao-chun Wu*†, Hans-Dieter Sues†‡§ & Ailing Sun*
*Institute of Vertebrate Paleontology and Paleoanthropology, Academia Sinica, Beijing 100044, China
†Department of Vertebrate Palaeontology, Royal Ontario Museum, 100 Queen's Park, Toronto, Ontario M5S 2C6, Canada
‡Department of Zoology, University of Toronto, Toronto, Ontario M5S 1A1, Canada
§To whom correspondence should be addressed at the Royal Ontario Museum
WITH few exceptions, tooth shape among crocodyliform reptiles (Crocodylia of traditional use) is rather uniform1. We report here on the presence of multicuspid molariform teeth in a remarkable new crocodyliform from the Lower Cretaceous of China, which may represent the first known herbivorous member of that group. The overall structure of these teeth is very similar to that of the postcanine teeth of tritylodontid synapsids and represents a particularly striking example of convergent evolution. It indicates back-to-front (proal) motion of the mandible produced by the posterior pterygoid muscle during jaw closing, much as in the extant tuatara, Sphenodon
2,3. Certain derived features indicate that the new Chinese crocodyliform is closely related to the Notosuchidae from the Cretaceous of Gondwana4. Its discovery thus casts further doubts on claims5 concerning an endemic Gondwanan tetrapod fauna during the Cretaceous.
||Langston, W. Jr in Biology of the Reptilia Vol. 4 (eds Gans, C. & Parsons, T. S.) 263−284 (Academic, New York, 1973).
||Gorniak, G. C., Rosenberg, H. I. & Gans, C. J. Morph. 171, 321−353 (1982).
||Wu, X.-c. thesis, McGill Univ. (1991).
||Gasparini, Z. B. de Ameghiniana 8, 83−103 (1971).
||Bonaparte, J. F. Actas IV Congr. Argentino Paleont. Bioestrat. 2, 63−95 (1986).
||Hao, Y. et al. Stratigraphy of China, Vol. 12: The Cretaceous System of China (Geological Publishing House, Beijing, 1986).
||Benton, M. J. & Clark, J. M. in The Phylogeny and Classification of the Tetrapods Vol. 1 (ed. Benton, M. J.) 295−338 (Clarendon, Oxford, 1988).
||Wu, X.-c., Brinkman, D. B. & Lü, J. J. vert. Paleont. 14, 210−229 (1994).
||Clark, J. M., Jacobs, L. L. & Downs, W. R. Science 244, 1064−1066 (1989). | ISI |
||Krause, D. W. Paleobiology 8, 265−281 (1982).
||Sues, H.-D. Bull. Mus. Comp. Zool., Harvard Univ. 151, 217−268 (1986).
||Schumacher, G.-H. in Biology of the Reptilia Vol. 4 (eds Gans, C. & Parsons, T. S.) 101−199 (Academic, New York, 1973).
||Busbey, A. B. J. Morph. 202, 99−127 (1989). | PubMed |
||Sereno, P. C., Wilson, J., Larsson, H. C. E., Dutheuil, D. B. & Sues, H.-D. Science 266, 267−271 (1994).
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