Sunday 30 March 2008

'Guarinisuchus munizi' - The New Brazilian Crocodile

Brazilian scientists unveiled one of the most complete skeletons found of prehistoric animals. The found skeleton, a pointy-nosed crocodile, baptized Guarinisuchus munizi, may have joined sharks as the dominant predators in the world's oceans some 62 million years ago.

The new specie is a crocodylomorpha and belongs to the Dyrosauridae group, formed by various sea species. The crocodylomorphs unite the crocodiles, gharials, caimans and alligators.
The bones of this crocodylomorpha specie were found in the north eastern state of Pernambuco, in a limestone mine in the region of Mina Poty at 30 km from Recife. This region is one of the few Brazilian paleontological sites where fossil material can be found from the period in which the dinosaurs were extinct, or being some 65 million years ago, between the Cretaceous and the Palaeocene periods.

Scientists named the species "Guarinisuchus" after the Tupi Indian word "Guarani," which means warrior and "munizi," in honour of Brazilian palaeontologist Deraldo da Costa Barros Muniz, who discovered many dinosaur fossils off Brazil's north eastern coast, although Muniz didn't participate in this find. One of the motives the scientists called the found crocodile “warrior” is because it survived the phenomenon which caused the extinction of the dinosaur. The second reason was: being a relatively small animal with a length of some 3 meters, it was a dominant predator.
Guarinisuchus appears to be closely related to marine crocodylomorphs found in Africa, which supports the hypothesis that the group originated in Africa and migrated to South America before spreading into the waters off the North American coast.

The find includes a skull, jaw bone and vertebrae, making it one of the most complete examples of marine crocodylomorphs collected so far in South America, according to Alexander Kellner of the National Museum of the Federal University of Rio de Janeiro.

Scientists have discovered a wealth of crocodile ancestors around Brazil in recent years. In January, they announced the discovery of an 80 million-year-old land-bound reptile described as a possible link between prehistoric and modern-day crocodiles.
Two years ago, palaeontologists from the Federal University of Rio de Janeiro announced the discovery of a 70-million-year-old crocodile fossil that they called Uberabasuchus Terrificus, or "Terrible Crocodile of Uberaba."

Photo captions from top to bottom:
01 - An artist impression of the life of the Guarinisuchus munizi, which lived near the coast of Northeast Brazil some 62 million years ago.
02 - The fossils were discovered in Mina Poty, north of Recife, in limestone deposits from the geological period between Cretaceous and Palaeogene (photo: A. Kellner)
03 - The top shows the skull of the Guarinisuchus munizi as found in Pernambuco, with the front part thin and long, characteristic for the Dyrosauridae. The bottom shows a reconstruction of the skull and the jaw.
04 - The map shows the possible dispersion of the Dyrosauridae, according to research results. These reptiles, original from Africa, have got to South America first and, soon afterwards to the north of the American continent. (Reproduction: Proceedings of the Royal Society B)
05 - The initial step of the reconstruction of the Guarinisuchus munizi. The replica of the new specie is displayed in the Museu Nacional/UFRJ in Rio de Janeiro (photo: João C. Ferreira).

Read more in the column of Alexander Kellner, scientist of the Museu Nacional/UFRJ in RJ.

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