A JUVENILE SAUROPODOMORPH TIBIA FROM THE 'BOTUCARAI HILL', LATE TRIASSIC OF SOUTHERN BRAZIL

Author(s)

Pretto, Flavio Augusto ; Veiga, Fabio Hiratsuka ; Langer, Max Cardoso ; Schultz, Cesar Leandro

• Document type: Journal article
• Source: Revista Brasileira de Paleontologia; v. 19, n. 3, p. 8-pg., 2016-09-01.

Abstract

The 'Botucarai Hill' outcrop yielded a diverse Late Triassic vertebrate fauna, including several dinosaur remains, but most collected specimens are represented only by isolated bones. We present here a new dinosaur tibia from that site, particularly notable for its small size. Anatomical comparisons and a phylogenetic analysis support a sauropodomouth affinity for the specimen. In addition, histological analyses on transverse sections of the tibial shaft revealed a very thin bone wall, characterized by woven matrix with high vascularization, and the complete absence of lines of arrested growth (LAGs). These features suggest that the specimen was undergoing rapid and uninterrupted bone growth prior to death. Indeed, the small size of the specimen, the poor ossification of the bone extremities, and the absence of LAGs indicate that it represents a juvenile individual, as not previously recorded for the Brazilian Upper Triassic dinosaur fauna. (AU)

• FAPESP's process: 14/03825-3 - The origin and rise of dinosaurs in Gondwana (late Triassic - early Jurassic)
• Grantee: Max Cardoso Langer
• Support Opportunities: Research Projects - Thematic Grants