Mesozoic dinosaurs from Brazil and their biogeographic implications

Jonathas S Bittencourt,Max C Langer

doi:10.1590/s0001-37652011000100003

Jonathas S Bittencourt, Max C Langer

Open Access

https://doi.org/10.1590/s0001-37652011000100003

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Abstract

The record of dinosaur body-fossils in the Brazilian Mesozoic is restricted to the Triassic of Rio Grande do Sul and Cretaceous of various parts of the country. This includes 21 named species, two of which were regarded as nomina dubia, and 19 consensually assigned to Dinosauria. Additional eight supraspecific taxa have been identified based on fragmentary specimens and numerous dinosaur footprints known in Brazil. In fact, most Brazilian specimens related to dinosaurs are composed of isolated teeth and vertebrae. Despite the increase of fieldwork during the last decade, there are still no dinosaur body-fossils of Jurassic age and the evidence of ornithischians in Brazil is very limited. Dinosaur faunas from this country are generally correlated with those from other parts of Gondwana throughout the Mesozoic. During the Late Triassic, there is a close correspondence to Argentina and other south-Pangaea areas. Mid-Cretaceous faunas of northeastern Brazil resemble those of coeval deposits of North Africa and Argentina. Southern hemisphere spinosaurids are restricted to Africa and Brazil, whereas abelisaurids are still unknown in the Early Cretaceous of the latter. Late Cretaceous dinosaur assemblages of south-central Brazil are endemic only to genus or, more conspicuously, to species level, sharing closely related taxa with Argentina, Madagascar, Indo-Pakistan and, to a lesser degree, continental Africa.

Highlights

The sesquicentennial history of dinosaur research in Brazil (e.g., Allport 1860, Marsh 1869, Mawson and Woodward 1907, Huene 1942, Price 1960, 1961, Colbert 1970, Arid and Vizotto 1971, Bertini and Campos 1987, Frey and Martill 1995, Kellner and Campos 1996) is experiencing, since the last decade, its more prolific period
We provide a reevaluation of the Brazilian dinosaur record from Triassic to Cretaceous ages based primarily on body-fossils, and discuss their relevance in the light of recent hypotheses dealing with dinosaur biogeography in the Mesozoic (Upchurch et al 2002, Sereno et al 2004, Krause et al 2006, Nesbitt et al 2009)
Terrestrial faunal endemism is not conspicuous across Pangaea in the Late Triassic (Benton 1993, Lucas 1998, Langer 2005a), and it is widely known that the tetrapod fauna of the Gondwana II Supersequence is correlated with those from Argentina, India, and southern Africa (Bonaparte 1969, 1973, 1982, Sill 1969, Barberena et al 1985, Scherer et al 1995, Lucas 1998, Ray and Chinsamy 2002, Langer 2005b, Kutty et al 2007), sharing more inclusive but closely related taxa with Europe and North America (Heckert and Lucas 1998, Langer 2005a)

Summary

INTRODUCTION

The sesquicentennial history of dinosaur research in Brazil (e.g., Allport 1860, Marsh 1869, Mawson and Woodward 1907, Huene 1942, Price 1960, 1961, Colbert 1970, Arid and Vizotto 1971, Bertini and Campos 1987, Frey and Martill 1995, Kellner and Campos 1996) is experiencing, since the last decade, its more prolific period. The dinosauriform Sacisaurus agudoensis from the Caturrita Formation (Ferigolo and Langer 2007) is allied with Silesaurus opolensis from the Carnian of Poland (Dzik 2003), in the Silesauridae This clade encompasses other species from North America, Africa, and South America (Irmis et al 2007a, Bittencourt and Langer 2009, Nesbitt et al 2009, 2010, Langer et al 2010), ranging from Anisian to Norian times. If silesaurids are not ornithischians, the low diversity of the latter group in comparison with saurischians in Late Triassic vertebrate assemblages remains to be satisfactorily explained This is especially intriguing for the Carnian-Norian of south Brazil, as ornithischian taxa are known from correlated deposits of both Argentina and South Africa (Casamiquela 1967, Báez and Marsicano 2001, Irmis et al 2007b, Butler et al 2007). This unit is composed of laminated limestone deposited in a lacustrine context during Aptian-Albian times

27 Cenozoic other Prosauropods**

DISCUSSION

Findings

CONCLUSIONS