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sábado, 3 de novembro de 2012

[Paleontology • 2011] Oxalaia quilombensis • A new dinosaur (Theropoda, Spinosauridae) from the Cretaceous (Cenomanian) Alcântara Formation, Cajual Island, Brazil

A life restoration of Oxalaia quilombensis.

(Image: Elaine Machado)

Abstract

A new spinosaurid taxon, Oxalaia quilombensis gen. et sp. nov., is described based on the anterior part of a snout and a fragment of a maxilla. These specimens were collected at the Laje do Coringa site, Late Cretaceous (Cenomanian) of the São Luis Basin. Unlike Cristatusaurus and Suchomimus, Oxalaia quilombensis lacks serrations on the teeth. The new species differs from Angaturama limai by having the anterior part of the premaxillae more expanded and by lacking a sagittal premaxillary crest. It further differs from Spinosaurus cf. S. aegyptiacus and the Algerian spinosaurid by the rounder shape of the terminal expansion. Furthermore, xalaia quilobensis has one functional tooth followed by two replacement teeth, a feature not previously observed in theropods. Oxalaia quilombensis appears to be more closely related to the spinosaurids found in North Africa than to the Brazilian members of this clade and thus further increases the diversity of these enigmatic predatory dinosaurs in this country.

Key words: Dinosauria, Spinosauridae, Oxalaia quilombensis, Cenomanian, Brazil.

SPINOSAURIDAE Stromer 1915

sensu Sereno et al. 1998

Oxalaia gen. nov.

Etymology: The generic name comes from Oxalá, the most respected masculine deity in the African pantheon, introduced in Brazil during slavery.

Type species: Oxalaia quilombensis sp. nov.

Diagnosis: as for the type and only species. Oxalaia quilombensis sp. nov.

Etymology: The generic name is derived from the Portuguese expression quilombo, the place where the quilombola (the descendants of former Brazilian slaves) live. The Cajual Island, where the specimens of this

new taxon were collected, is one of these places.

Kellner, Alexander W.A.; Sergio A.K. Azevedeo, Elaine B. Machado, Luciana B. Carvalho and Deise D.R. Henriques (2011). "A new dinosaur (Theropoda, Spinosauridae) from the Cretaceous (Cenomanian) Alcântara Formation, Cajual Island, Brazil". Anais da Academia Brasileira de Ciências 83 (1): 99–108. doi:10.1590/S0001-37652011000100006