Abstract
Here we report the discovery of a small-bodied (∼1.8 m) predatory dinosaur from the Late Cretaceous (Maastrichtian) of Madagascar. Masiakasaurus knopfleri, gen. et sp. nov., represented by several skull elements and much of the postcranial skeleton, is unique in being the only known theropod with a highly procumbent and distinctly heterodont lower dentition. Such a derived dental morphology is otherwise unknown among dinosaurs. Numerous skeletal characteristics indicate that Masiakasaurus is a member of Abelisauroidea, an enigmatic clade of Gondwanan theropods. Previously, small-bodied abelisauroids were known only from Argentina1,2,3. The occurrence of Masiakasaurus on Madagascar suggests that small-bodied abelisauroids, like their larger-bodied counterparts, were more cosmopolitan, radiating throughout much of Gondwana and paralleling the diversification of small coelurosaur theropods in Laurasia.
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References
Bonaparte, J. F. & Powell, J. E. A continental assemblage of tetrapods from the Upper Cretaceous beds of El Brete, northwestern Argentina (Sauropoda-Coelurosauria-Carnosauria-Aves). Mém. Soc. Géol. Fra. 139, 19–28 (1980).
Bonaparte, J. F. The Gondwanian theropod families Abelisauridae and Noasauridae. Hist. Biol. 5, 1–25 (1991).
Bonaparte, J. F. Cretaceous tetrapods of Argentina. Geowiss. Abhand. 30, 73–130 (1996).
Krause, D. W., Prasad, G. V. R., von Koenigswald, W., Sahni, A. & Grine, F. E. Cosmopolitanism among Gondwanan Late Cretaceous mammals. Nature 390, 504–507 (1997).
Sampson, S. D. et al. Predatory dinosaur remains from Madagascar: implications for the Cretaceous biogeography of Gondwana. Science 280, 1048–1051 (1998).
Krause, D. W. et al. The Late Cretaceous vertebrate fauna of Madagascar: implications for Gondwanan paleobiogeography. GSA Today 9, 1–7 (1999).
Forster, C. A., Sampson, S. D., Chiappe, L. M. & Krause, D. W. The theropod ancestry of birds: new evidence from the Late Cretaceous of Madagascar. Science 279, 1915–1919 (1998).
Rogers, R. R., Hartman, J. H. & Krause, D. W. Stratigraphic analysis of Upper Cretaceous strata in the Mahajanga Basin, Madagascar: implications for ancient and modern faunas. J. Geol. 108, 275–301 (2000).
Sereno, P. C., Forster, C. A., Rogers, R. R. & Monetta, A. M. Primitive dinosaur skeleton from Argentina and the early evolution of Dinosauria. Nature 361, 64–66 (1993).
Gauthier, J. in The Origin of Birds and the Evolution of Flight (ed. Padian, K.) 1–47 (Memoirs of the California Academy of Sciences, San Francisco, 1986).
Holtz, T. R. Jr The phylogenetic position of the Tyrannosauridae: implications for theropod systematics. J. Paleontol. 68, 1100–1117 (1994).
Sereno, P. C. The origin and evolution of dinosaurs. Annu. Rev. Earth Planet. Sci. 25, 435–489 (1997).
Sereno, P. C. The evolution of dinosaurs. Science 284, 2137–2147 (1999).
Rauhut, O. Elaphrosaurus bambergi and the early evolution of theropod dinosaurs. J. Vert. Paleontol. 18, 71A (1998).
Carrano, M. T. & Sampson, S. D. Evidence for a paraphyletic ‘Ceratosauria’ and its implications for theropod dinosaur evolution. J. Vert. Paleontol. 19, 36A (1999).
Forster, C. A. Gondwanan dinosaur evolution and biogeographic analysis. J. Af. Earth Sci. 28, 169–185 (1999).
Novas, F. E. in The Encyclopedia of Dinosaurs (eds Currie, P. J. & Padian, K) 1–2 (Academic, New York, 1997).
Bonaparte, J. F. Los vertebrados fósiles de la Formación Rio Colorado, de la Ciudad de Neuquén y cercancias, Cretácico Superior, Argentina. Paleontologia 4, 16–123 (1991).
Huene, F. v. & Matley, C. A. The Cretaceous Saurischia and Ornithischia of the central provinces of India. Palaeontol. Indica 21, 1–72 (1933).
Acknowledgements
We thank A. Rasoamiaramanana, B. Rakotosamimanana, P. Wright, B. Andriamihaja and the staff of the Institute for the Conservation of Tropical Environments for help with fieldwork in Madagascar; members of the 1993, 1995, 1996, 1998 and 1999 expeditions for their efforts; F. Novas amd P. Currie for photographs of Noasaurus; D. Krause for comments on earlier drafts of the manuscript; V. Heisey for preparation; F. Grine for scanning electron microscope photography; and L. Betti-Nash and J. Higgins for assistance with the figures. This work was funded by grants from the National Science Foundation, the National Geographic Society, and the Dinosaur Society.
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Sampson, S., Carrano, M. & Forster, C. A bizarre predatory dinosaur from the Late Cretaceous of Madagascar. Nature 409, 504–506 (2001). https://doi.org/10.1038/35054046
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DOI: https://doi.org/10.1038/35054046
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