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[dinosaur] Torvoneustes (Metriorhynchidae) from Mexico + crocodyliforms from Marília Formation, Brazil (free pdfs)

Ben Creisler

New papers in open access:

Jair I. Barrientos-Lara (2016) [2017]

Occurrence of Torvoneustes (Crocodylomorpha, Metriorhynchidae) in marine Jurassic deposits of Oaxaca, Mexico.

Revista Brasileira de Paleontologia 19(3):415-424

doi: 10.4072/rbp.2016.3.07


IGM 9026 is a singular fossil collected at the beginning of the 20th century in an improperly documented site within the Tlaxiaco Basin, near to Tlaxiaco town, Oaxaca, Mexico. The age of the site was suggested as being early Cretaceous. This specimen is the holotype of Plesiosaurus (Polypticodon) mexicanus, which later was identified as a possible late Jurassic marine crocodylomorph of the family Metriorhynchidae, and consequently it was referred as ?Cricosaurus mexicanus. The present study provides a re-description of this fossil based on a microscopic analysis and the use of white and UV lights; these analyses led to the discovery of peculiar dental characters diagnostic of the genus Torvoneustes. This finding supports the re-classification of IGM 9026 under a new nominal combination as Torvoneustes mexicanus. Along the Tlaxiaco Basin, the fossil preservation mode and lithological composition observed in IGM 9026 only occur in the marine vertebrates recently discovered in Yosobé, a Kimmeridgian shale outcrop characterized by clay calcareous nodules that belong to the Sabinal Formation, near Tlaxiaco town. This peculiarity suggests that T. mexicanus could represent an additional element of the Kimmeridgian vertebrate assemblage recovered in this geological unit. The two nominal species of Torvoneustes were collected in Kimmeridgian marine deposits of England; hence, this finding expands the geographical distribution of Torvoneustes all along the Tethys Sea, from its Eastern/European to western/ Caribbean domains.


Fabiano Vidoi Iori & Antonio Celso de Arruda Campos (2016)

Os crocodiliformes da formação marília (Bacia Bauru, Cretáceo superior) na região de Monte Alto, Estado de São Paulo, Brasil. [The crocodyliforms from the Marília Formation (Bauru Basin, Upper Cretaceous) in the Monte Alto region, São Paulo State, Brazil.]

Revista Brasileira de Paleontologia  19(3):537-546

doi: 10.4072/rbp.2016.3.17 


This study presents the oldest historical record of fossil crocodyliforms in the region of the Monte Alto, SP, besides the analysis of an additional fossil from the same site. The specimens come from the Marília Formation and they are the only known local occurrences of Crocodyliformes cranial fragments in this stratigraphic unit. This study expands the knowledge about Crocodyliformes of the Bauru Basin and contributes to the definition of the regional paleofauna during the Maastrichtian.