Pictures: New Dinosaur, Crocodile Cousin Found in Brazil

Classic Croc

Photograph by Marcos de Paula, Agencia Estado/AP

A replica of the newfound crocodile cousin—pictured next to its skull and jawbone in March—shows how similar the ancient reptiles were to their modern cousins, Kellner said.

Crocodyliforms, which arose in the Mesozoic period (251 to 65 million years ago), evolved adaptations to different habitats without changing their bodies much, he said.

For instance, most crocodyliforms had relatively short legs and a head adapted for keeping their eyes and nostrils above water.

(See "New Prehistoric Crocodile Found in 'Kitchen Counters.'")

Published March 30, 2011

Toothy Tyrant

Illustration courtesy Maurilio Oliveria, Brazilian National Museum/UFRJ

Remains of the 95-million-year-old dinosaur Oxalaia quilombensis, shown above in an artist's illustration, were recently found in northeastern Brazil's Maranhão state.

Teeth like those of the newfound dinosaur have never been seen before in theropods, the group of two-legged carnivores that includes Tyrannosaurus rex and Velociraptor.

That's because the 46-foot-long (14-meter-long) O. quilombensis had two rows of extra teeth on both sides of its mouth, suggesting it could replace worn or broken teeth.

"While one was in use, two others were already being developed. This is a common feature in sharks or in some reptiles, but not in theropods," Kellner said.

(See "Massive New Meat-Eating Dino Had 'Steak Knife' Teeth.")

Published March 30, 2011

Alligator-Like Dinosaur

Photograph by Marcos de Paula, Agencia Estado/AP

Brazilian National Museum paleontologist Elaine Machado holds a snout fragment of the new dinosaur O. quilombensis in front of its illustration in March. The artwork was based on pieces of the dinosaur's jaw and snout.

O. quilombensis belonged to a group of long-snouted dinosaurs called the spinosaurids.

"Spinosaurid heads in general resemble [those of] alligators—that's a common feature," Kellner said.

The new Brazilian species seems to be more closely related to other spinosaurids found in northern Africa than those from Brazil, he added.

This similarity suggests the ancestors of the African and Brazilian species came from the same area before the African and South American continents separated between 130 million and 110 million years ago.

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Published March 30, 2011