Produção Nacional
Revisado por pares
A new Eocaiman (Alligatoridae, Crocodylia) from the Itaboraí Basin, Paleogene of Rio de Janeiro, Brazil
2013; Taylor & Francis; Volume: 25; Issue: 3 Linguagem: Inglês
10.1080/08912963.2012.705838
ISSN1029-2381
AutoresAndré Eduardo Piacentini Pinheiro, Daniel Fortier, Diego Pol, Diógenes de Almeida Campos, Lílian Paglarelli Bergqvist,
Tópico(s)Evolution and Paleontology Studies
ResumoAbstract A new small species of Eocaiman is described on the basis of three anterior left mandibular rami and one isolated tooth. The specimens came from the middle-upper Paleocene Itaboraí Basin (Rio de Janeiro State, Brazil; Itaboraian South American Land Mammal Age). The new taxon differs from the other two Eocaiman species, such as its small size, likely participation of the splenial in the mandibular symphysis, a reduced angle between the longitudinal axis of the symphysis and the mandibular ramus, and enlarged ninth and tenth dentary teeth (in addition to the large first and fourth dentary teeth). The participation of the splenial in the mandibular symphysis is a unique character among caimanines (with the only possible exception being Tsoabichi greenriverensis). The new taxon provides new information on the taxonomic and anatomical diversity of the genus Eocaiman, a taxon of prime importance to understand the evolutionary origins of caimans given its position as the basalmost member of Caimaninae. Furthermore, the new taxon has a relatively small body size in comparison with other species of Eocaiman, a case paralleled by other Itaboraian reptilian groups (e.g. snakes), suggesting that this ecosystem provides critical data to test the relationship between reptilian body size and climate. http://zoobank.org/83636F22-D121-4A77-9141-BE68987B6CBF Keywords: CrocodyliformesAlligatoroideaCaimaninae Eocaiman ItaboraiPaleogene Acknowledgements For access to and assistance with collections, we thank C. Mehling (AMNH), R. Machado (CPRM/DNPM), A. Resetar and K. Lawson (FMNH), J. Cundiff (MCZ), P. Holroyd (UCMP), A. Hasting, K. Krysko and R. Hulbert (UF), and A. Wynn and J. Jacobs (USNM). The Florida Museum of the Natural History, the University of California Museum of Paleontology and the Brazilian agencies CAPES and CNPq funded collection visits by DF while FONCyT PICT 0736 provided support to D. Pol. C.A. Brochu (UI) kindly provided photos of E. cavernensis and critical comments. Thanks to F.S. Silva and C.W. Gabriel (LAFO and LAGESED of DEGEO/CCMN/UFRJ) for microscopic photos of Figure 5. Thanks also to C. Martinez (ULA) for suggestions. TNT is a free program made available by the Willi Hennig Society. Notes 1. danielcfortier@yahoo.com.br 2. dpol@mef.org.ar 3. dac@abc.org.br 4. bergqvist@geologia.ufrj.br Additional informationNotes on contributorsDaniel C. Fortier 1 1. danielcfortier@yahoo.com.br Diego Pol 2 2. dpol@mef.org.ar Diógenes A. Campos 3 3. dac@abc.org.br Lílian P. Bergqvist 4 4. bergqvist@geologia.ufrj.br
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