A new Sphagesaurus (Mesoeucrocodylia: Notosuchia) from the Upper Cretaceous of Monte Alto City (Bauru Group, Brazil), and a revision of the Sphagesauridae

Abstract

Since the description of Sphagesaurus, mostly dental material has been reported, apart from two incomplete skulls. Here we describe a new species of Sphagesaurus, from Monte Alto City, Southeastern Brazil, which includes the skull and most of the mandible. Distinctive characters (e.g. antorbital fenestra; robust quadrate; anterior mandibular teeth incisiform; ornamented sulcate palate) allow differentiation from S. huenei. Several characters allow assignment to the genus Sphagesaurus (e.g. teardrop-like oblique molariform teeth), while new information is provided (e.g. premaxilla, pterygoid and mandible morphology; jugal foramen; occipital surface; battery of mandibular teeth). A revision of the Family Sphagesauridae Kuhn 1968 is given. A preliminary phylogenetic analysis supports a sister-taxon relationship for S. huenei and the new species. The phylogenetic relationship of notosuchians is explored. Sphagesaurids were terrestrial notosuchians that evolved during the Upper Cretaceous of South America, known only from the Adamantina Formation, Campanian–Maastrichtian (Upper Cretaceous) from Brazil.

Keywords:

• Sphagesaurus
• Mesoeucrocodylia
• Notosuchia
• Cretaceous
• Bauru Group
• Brazil

Acknowledgements

The authors are grateful to A. C. Arruda-Campos (MPMA), for the access to the MPMA 15-001/90 specimen. We would also like to thank A. Kramarz (MACN), A. W. A. Kellner (MN–UFRJ), D. A. Campos (DNPM), F. Novas (MACN), J. F. Bonaparte (MACN), J. O. Calvo (Proyecto Dino), L. Carvalho (MN–UFRJ), M. Reguero (MLP), S. A. K. de Azevedo (MN–UFRJ), S. Bargo (MLP) and Z. N. B. Gasparini (MLP), for access to materials either under their care or study. Corrections by Diego Pol (MEF), Alan Turner (AMNH) and Gareth Dyke (UCD) greatly contributed to the development of the manuscript. The authors thanks to Cástor Cartelle Guerra (PUC), for important information on the outcrop of the RCL-100 specimen; José F. Bonaparte (MACN), for valuable suggestions regarding the study of Sphagesaurus and Notosuchus specimens; Diego Pol (MEF), for his suggestions, criticism and generous comments on the morphology of Sphagesaurus; A. E. P. Pinheiro (NEPV-IGCE-UNESP), for useful comments on the morphology of baurusuchids. Credit also is due to: Michael J. Benton (DES-University of Bristol), for his helpful revision of the manuscript; Lilia M. D. Bertini (NEPV-IGCE-UNESP), for preparation of the specimen; Felipe A. Elias (NEPV-IGCE-UNESP), for the pictorial reconstruction of S. montealtensis; Simon Powell (DES-University of Bristol), for valuable directions on image treatment. Financial support for this study was provided by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), Brazil. MBA is currently supported by the Conselho Nacional de Desenvolvimento Cientifico e Tecnológico (CNPq – Proc. no. 200391/2006–8), Brazil.

Notes

Additional information

Notes on contributors

Reinaldo J. Bertini

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