Archives of The Cold Blooded News

The Newsletter of the Colorado Herpetological Society

Volume 33, Number 5;   May, 2006

Ancient "Godzilla" Crocodile Described

The researchers described fossils of an ancient crocodile found at the southern tip of South America whose massive jaws and jagged teeth, they said, would have made it the sea's most fearsome predator.

Researchers say they have found evidence of a sea creature that would have made Tyrannosaurus rex think twice before stepping into the ocean.

Unlike today's crocodiles, Dakosaurus andiniensis lived entirely in the water, researchers say, and had fins instead of legs. In addition, its hefty size and T. rex-like snout have earned it the nickname "Godzilla" from scientists.

Diego Pol of Ohio State University said the oddly shaped fossils belong on the crocodile family tree.

"This species was very unusual, because other marine crocodiles that were around at the same time had very delicate features - long, skinny snouts and needle-like teeth for catching small fish and mollusks," he said. "But this croc was just the opposite. It had a short snout, and large teeth with serrated edges."

These features indicate it was a predator of large sea creatures, he added.

Paleontologists Zulma Gasparini and Luis Spalletti of the National University of La Plata in Argentina uncovered the fossil bones in Patagonia, a region of South America in southern Argentina and Chile.

Pol used software to map the features of those bones and determine its lineage. Together, they describe the creature in the Nov. 11 issue of the research journal Science.

The animal measured 13 feet (4 meters) from nose to tail, researchers said. Its jaws were a 18 inches (46 cm) long, with interlocking serrated teeth up to four inches (10 cm) long.

Marine crocodile species of many other sizes lived 135 million years ago, toward the end of the Jurassic era, but all had long snouts and needle-like teeth, the researchers said. None were larger than D. andiniensis, nor as robust, they added.

Yet, Pol found that the gargantuan crocodile was more closely related to the smallest of its brethren than any of the larger species. He explained that the shape of the nostrils, eye sockets, and other areas of the skull combined with a telltale groove in its jaw to indicate its lineage.

"This is the most remarkable change in the size and shape of the teeth and snout in the history of marine crocs," Pol said.

The three fossil specimens were found in 1996, the researchers said - one on farmland in the Mendoza province of Patagonia, and two in a rock formation in Neuquen province to the south. When D. andiniensis lived, the researchers added, the region was a deep tropical bay of the Pacific Ocean.

The researchers don't know what triggered the sudden emergence of the large crocodile. But they say the size and shape of the teeth suggest it ate other marine reptiles and large sea creatures in the bay instead of small fish.