Dinosaur remains from the 'Botucarai Hill' (Caturrita Formation), Late Triassic of south Brazil, and their stratigraphic context

Author(s)

Bittencourt, Jonathas Souza ; Stock da Rosa, Atila Augusto ; Schultz, Cesar Leandro ; Langer, Max Cardoso

• Document type: Journal article
• Source: HISTORICAL BIOLOGY; v. 25, n. 1, p. 13-pg., 2013-02-01.

Abstract

Vertebrate fossils recovered from sites nearby the Botucarai Hill and Candelaria (Caturrita Formation) depict a diverse Late Triassic tetrapod fauna from south Brazil. These records are of key importance to the biostratigraphy of the upper sections of the Rosario do Sul Group. A lithological and biostratigraphic survey on the main fossil localities of the Botucarai Hill area confirms the occurrence of the lower Hyperodapedon and the upper Riograndia Assemblage Zones in the region, the latter yielding early saurischians. In this paper, three incomplete dinosaur specimens, an isolated sacral vertebra, an articulated left pubisischium and an isolated right ischium, from the Botucarai Hill site are described. A comparative survey suggests that these specimens have sauropodomorph affinities, but probably more primitive than typical prosauropods from the Norian-Early Jurassic. Regardless of the phylogenetic position of Guaibasaurus as theropod or sauropodomorph, their occurrence in the Caturrita Formation, which also yielded core prosauropods from the Santa Maria region, suggests either the survival of early members of the clade with more derived prosauropods or that heterochronous faunas are sampled from that stratigraphic unit. (AU)

• FAPESP's process: 10/08891-3 - Anatomy and systematics of the dinosauromorphs from the Ladinian of the Chañares Formation, Argentina, and the origin of dinosaurs
• Grantee: Jonathas de Souza Bittencourt Rodrigues
• Support Opportunities: Scholarships in Brazil - Post-Doctoral