Scientists Find The T. Rex Of Crocodiles
By KENNETH CHANG
Published: November 11, 2005
Scientists have nicknamed it Godzilla, but it really belongs in another movie, one not yet made but possibly titled: ''Jaws Meets Jurassic Park.''
The creature, whose discovery is being announced today in the journal Science, is a large sea-dwelling crocodile that lived 135 million years ago, in the middle of the dinosaur era.
Unlike most crocodiles today, this one possessed a snout that was short and stout, like that of Tyrannosaurus rex, and its foot-and-a-half-long jaws held 52 large teeth with serrated edges -- the type that can tear chunks of flesh out of other large creatures.
''I'm sure it wasn't nice,'' said Diego Pol, a researcher at the Mathematical Biosciences Institute at Ohio State University and a member of the research team. ''A top predator role in the food chain.''
Perhaps a dozen or more feet long, it was not the largest of all crocodiles, nor was it the only one that swam the seas. But it is notable for being so sharply distinct from most other crocodiles, which generally have long, slender snouts and a mouthful of more than 100 small sharp teeth, useful for catching fish.
''It's like a crocodile with a dinosaur head on it,'' said James M. Clark, who is a professor of biology at George Washington University but was not involved in the research. ''This is something really new and unusual. In the realm of fossil marine crocodiles, it's a big deal.''
Mark A. Norell, curator of paleontology at the American Museum of Natural History, said this crocodile could have filled an ecological niche similar to that of modern-day killer whales.
Dr. Pol said it probably preyed on other marine reptiles like ichthyosaurs, which looked like dolphins, and plesiosaurs, the long-necked, slow-swimming reptiles.
Paleontologists have known about crocodiles living in the oceans since the 1800's, when their fossils were found in Europe. Some had even evolved flippers and a fishlike tail.
The research, financed by the National Geographic Society, was led by Zulma Gasparini, a paleontologist at the National University of La Plata in Argentina. She uncovered a complete, intact fossil skull of the new species, named Dakosaurus andiniensis, in the Patagonia region in 1996. The Science article culminates nine years of study, including preparing the fossil by removing the surrounding rock.
Despite its unusual shape, the 13-inch-long skull had telltale features like the shape of the nostrils, eye sockets and the roof of the mouth that indicated it was a crocodile. A detailed comparison by Dr. Pol with other marine crocodiles of the time indicated that the new species resembled the group with the flippers and fishlike tails.
When Dakosaurus lived, the area where the fossil was found was far to the north and far underwater, the bottom of a deep tropical bay connected to the Pacific Ocean.
Photo: Nicknamed Godzilla, the Dakosaurus andiniensis ruled the seas about 135 million years ago. (Photo by National Geographic)