Fossil crocodyliforms discovered in recent years1,2,3,4,5 have revealed a level of morphological and ecological diversity not exhibited by extant members of the group. This diversity is particularly notable among taxa of the Cretaceous Period (144–65 million years ago) recovered from former Gondwanan landmasses. Here we report the discovery of a new species of Cretaceous notosuchian crocodyliform from the Rukwa Rift Basin6 of southwestern Tanzania. This small-bodied form deviates significantly from more typical crocodyliform craniodental morphologies, having a short, broad skull, robust lower jaw, and a dentition with relatively few teeth that nonetheless show marked heterodonty. The presence of morphologically complex, complementary upper and lower molariform teeth suggests a degree of crown–crown contact during jaw adduction that is unmatched among known crocodyliforms, paralleling the level of occlusal complexity seen in mammals and their extinct relatives7,8,9,10,11,12. The presence of another small-bodied mammal-like crocodyliform in the Cretaceous of Gondwana indicates that notosuchians probably filled niches and inhabited ecomorphospace that were otherwise occupied by mammals on northern continents.
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Buckley, G. A. et al. A pug-nosed crocodyliform from the Late Cretaceous of Madagascar. Nature 405, 941–944 (2000)
Zaher, H. et al. Redescription of the cranial morphology of Mariliasuchus amarali, and it phylogenetic affinities (Crocodyliformes, Notosuchia). Amer. Mus. Nov. 3512, 1–40 (2006)
Nobre, P. H. & Carvalho, I. S. Adamantinasuchus navae: A new Gondwanan Crocodylomorpha (Mesoeucrocodylia) from the Late Cretaceous of Brazil. Gond. Res. 10, 370–378 (2006)
Pol, D. New remains of Sphagesaurus huenei (Crocodylomopha: Mesoeucrocodylia) from the Late Cretaceous of Brazil. J. Vertebr. Paleontol. 23, 817–831 (2003)
Pol, D. & Apesteguía, S. New Araripesuchus remains from the early Late Cretaceous (Cenomanian-Turonian) of Patagonia. Amer. Mus. Nov. 3490, 1–38 (2005)
Roberts, E. M. et al. Sedimentology and depositional environments of the Red Sandstone Group, Rukwa Rift basin, southwestern Tanzania: new insight into Cretaceous and Paleogene terrestrial ecosystems and tectonics in sub-equatorial Africa. J. Afr. Earth Sci. 57, 179–212 (2010)
Kemp, T. S. The Origin and Evolution of Mammals (Oxford Univ. Press, 2005)
Angielczyk, K. D. Phylogenetic evidence for and implications of a dual origin of propaliny in anomodont therapsids (Synapsida). Paleobiol. 30, 268–296 (2004)
Crompton, A. W. & Jenkins, F. A. Molar occlusion in Late Triassic Mammals. Biol. Rev. Camb. Philos. Soc. 43, 427–458 (1968)
Luo, Z.-X. Transformation and diversification in early mammal evolution. Nature 450, 1011–1019 (2007)
Kielan-Jaworowski, Z. et al. Mammals from the Age of Dinosaurs Origins, Evolution, and Structure. (Columbia Univ. Press, New York, 2004)
Luo, Z.-X., Crompton, A. W. & Sun, A.-L. A new mammaliaform from the Early Jurassic and evolution of mammalian characteristics. Science 292, 1535–1540 (2001)
O'Connor, P. M. et al. A new vertebrate fauna from the Cretaceous Red Sandstone Group, Rukwa Rift Basin, Southwestern Tanzania. J. Afr. Earth Sci. 44, 277–288 (2006)
Andrade, M. B. & Bertini, R. J. Morphological and anatomical observations about Mariliasuchus amarali and Notosuchus terrestris (Mesoeucrocodylia) and their relationships with other South American notosuchians. Aq. Mus. Nac., Rio de Jan. 66, 5–62 (2008)
Gomani, E. M. A crocodyliform from the Early Cretaceous Dinosaur Beds, Northern Malawi. J. Vertebr. Paleontol. 17, 280–294 (1997)
Turner, A. H. Osteology and phylogeny of a new species of Araripesuchus (Crocodyliformes: Mesoeucrocodylia) from the Late Cretaceous of Madagascar. Hist. Biol. 18, 255–369 (2006)
Fiorelli, L. & Calvo, J. O. New remains of Notosuchus terrestris Woodward, 1896 (Crocodyliformes: Mesoeucrocodylia) from the Late Cretaceous of Neuquén, Patagonia, Argentina. Aq. Mus. Nac., Rio de Jan. 66, 83–124 (2008)
Lecuona, A. & Pol, D. Tooth morphology of Notosuchus terrestris (Notosuchia: Mesoeucrocodylia): New evidence and implications. C. R. Palevol 7, 407–417 (2008)
Novas, F. E. et al. Bizarre notosuchian crocodyliform with associated eggs from the Upper Cretaceous of Bolivia. J. Vertebr. Paleontol. 29, 1316–1320 (2009)
Carvalho, I. S. Candidodon: Um crocodile com heterodontia (Notosuchia, Cretáceo Infereior – Brasil). An. Acad. Bras. Cienc. 66, 331–346 (1994)
Nobre, P. H. et al. Feeding behavior of the Gondwanic Crocodylomorpha Mariliasuchus amarali from the Upper Cretaceous Bauru Basin, Brazil. Gond. Res. 13, 139–145 (2008)
Pletsch, T. et al. Cretaceous separation of Africa and South America: The view from the West African margin (ODP Leg 159). J. S. Am. Earth Sci. 14, 147–174 (2001)
Krause, D. W. et al. Cosmopolitanism among Gondwanan Late Cretaceous mammals. Nature 390, 504–507 (1997)
Bonaparte, J. F. A new and unusual Late Cretaceous mammal from Patagonia. J. Vertebr. Paleontol. 6, 264–270 (1986)
Krause, D. W. et al. A Cretaceous mammal from Tanzania. Acta Palaeontol. Pol. 48, 321–330 (2003)
Jernvall, J., Keränen, S. V. E. & Thesleff, I. Evolutionary modification of development in mammaliam teeth: Quantifying gene expression patterns and topography. Proc. Natl Acad. Sci. USA 97, 14444–14448 (2000)
Kangas, A. T. et al. Nonindependence of mammalian dental characters. Nature 432, 211–214 (2004)
Tummers, M. & Thesleff, I. The importance of signal pathway modulation in all aspects of tooth development. J. Exp. Biol. 312, 309–319 (2009)
Zhao, Z., Weiss, K. M. & Stock, D. W. in Development, Function and Evolution of Teeth (eds Teaford, M. F., Meredith Smith, M., & Ferguson, M. W. J.) 152–172 (Cambridge Univ. Press, 2007)
Osborn, J. W. Relationship between growth and the pattern of tooth initiation in alligator embryos. J. Dent. Res. 77, 1730–1738 (1998)
We thank: D. Kamamba, F. Ndunguru (Tanzania Antiquities Unit), P. Msemwa (Tanzania Museum of House of Culture), I. Marobhe (University of Dar es Salaam), and the Tanzania Commission for Science and Technology for support; J.P. Cavigelli and V. Heisey for specimen preparation; M. Getty, E. Lund, S. Burch, V. Simons, E. Simons, J. Garcia-Massini, G. Masai, and A. Mussa for field assistance; P. Sereno, E. Gomani, and C. Chiumia for specimen access; J. Sidote for digital processing assistance. This research was supported by the US National Science Foundation (NSF EAR-0617561, EAR-0854218), the National Geographic Society (CRE), the University of the Witwatersrand, the Michigan State University Office of Research and Graduate Studies, and the Ohio University College of Osteopathic Medicine and Ohio University Office of Research and Sponsored Programs.
The authors declare no competing financial interests.
This file contains Supplementary Information and Data which also includes Supplementary Figures S1-S4 with legends, a Character List for Phylogenetic Analysis, a Data Matrix, legends for Supplementary Movies 1 and 2 and References. (PDF 687 kb)
Movie RRBP 08631 shows the reconstruction of the left side of a holotype skull, highlighting the upper and lower dentition and associated skull elements. (MOV 7192 kb)
Movie RRBP 05103 shows the reconstruction of a fragmentary skull preserving left maxilla, lower jaw and partially-preserved complement of postcaniniform teeth. (MOV 7343 kb)
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O’Connor, P., Sertich, J., Stevens, N. et al. The evolution of mammal-like crocodyliforms in the Cretaceous Period of Gondwana. Nature 466, 748–751 (2010). https://doi.org/10.1038/nature09061
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