A new dinosaur (Theropoda, Spinosauridae) from the Cretaceous (Cenomanian) Alcântara Formation, Cajual Island, Brazil.

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.

A new dinosaur (Theropoda, Spinosauridae) from the Cretaceous (Cenomanian) Alcântara Formation, Cajual Island, Brazil

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.

Um novo espinossaurideo, Oxalaia quilombensis gen. et sp. nov., e descrito com base na parte anterior de um rostro e de um fragmento da maxila. Os especimes sao procedentes do deposito Laje do Coringa, formado durante o Cretacéo Superior (Cenomaniano) da Bacia de São Luis. Ao contrario de Cristatusaurus e Suchoius, xalaia quilobensis nao possui dentes serrilhados. A nova especie difere de Angaturama limai pela ausencia de crista sagital e por possuir a região do rostro mais expandida. Tambem difere de Spinosaurus cf. S. aegyptiacus e do espinossaurideo da Argelia pelo rostro mais arredondado. Além disso, Oxalaia quilombensis possui dois dentes de substituição no terceiro par de dentes pre-maxilares, uma feição até então desconhecida em teropodes. Oxalaia quilombensis esta aparentemente mais proximamente relacionado aos espinossaurideos da regiao norte da frica do que as formas brasileiras e aumenta a diversidade deste grupo enigmatico de dinossauros predadores no pais.