Ancient Croc Discovered [LiveScience 2008-03-27]
Ancient Croc Discovered
RIO DE JANEIRO, Brazil (AP) — Pointy-nosed crocodiles may have joined sharks as the dominant predators in the world's oceans some 62 million years ago, according to Brazilian scientists who on Wednesday unveiled one of the most complete skeletons found yet of the prehistoric animals.
Scientists called it a new species, "Guarinisuchus munizi," and said it sheds new light on the evolutionary history of modern crocodiles.
The fossil includes a skull, jaw bone and vertebrae, making it one of the most complete examples of marine crocodylomorphs collected so far in South America, said Alexander Kellner of the National Museum of the Federal University of Rio de Janeiro. He and other scientists unveiled fossils and a model of the 10-foot-long crocodile at the museum.
"It's a very rare find and it gives rise to several new theories," said Kellner, who co-authored an article on the find that was published Tuesday in Proceedings of The Royal Society B, a London-based peer-reviewed journal.
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, Kellner said.
The find also suggests that marine crocodylomorphs replaced marine lizards during the early Paleocene era, about 65 million years ago — the same time marine lizards became extinct. They believe it's a new species based on anatomical differences in the skull that are unique to this creature.
Philip Currie, a paleontology professor at the University of Alberta, Canada who was not involved with the discovery, said it was an important find.
"There are a lot of unknowns with this group in terms of evolution. Clearly the discovery of a specimen as nice as this one will help sort things out," Currie said in telephone interview.
The bones were found in the northeastern state of Pernambuco. Scientists named the species Guarinisuchus after the Tupi Indian word "Guarani," which means warrior and "munizi," in honor of Brazilian paleontologist Deraldo da Costa Barros Muniz, who has discovered many dinosaur fossils off Brazil's northeastern coast. Muniz didn't participate in this find.
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, paleontologists 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."
— Michael Astor, The Associated Press