'Godzilla' of the deep resurfaces

Published on 11/11/2005 01:37

A TERRIFYING sea creature that had the head of a dinosaur, the body of a crocodile and the fins of a fish and ruled the deep 135 million years ago has been unearthed by palaeontologists.

Fossil remains of the predator, Dakosaurus andiniensis, which has already been nicknamed "Godzilla", have been uncovered in Patagonia, Argentina, in a region that was once a deep tropical bay.

The creature measured 13 feet from nose to tail and had a powerful 18in-long snout, with interlocking serrated teeth up to 4in long.

But although a similar size to modern-day crocodiles, which have been known to grow to a length of up to 19ft, scientists were struck by the animal's unusual bullet-shaped skull and massive jaws - earning it the Hollywood-style nickname.

It was also more ferocious looking than a crocodile. The teeth were designed like steak knives with serrated edges, resembling those of terrestrial dinosaurs and marked Dako-saurus andiniensis out as a hunter of large marine reptiles or sea creatures, rather than fish. Scientists have even suggested it might attack other dinosaurs, and make Tyrannosaurus rex think twice before stepping into the ocean.

However, Diego Pol, a postdoctoral researcher at the Department of Biomedical Informatics at Ohio State University, found that Godzilla was part of the same family as the marine crocodile, but unlike any of its relatives.

"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 molluscs," he said.

"But this croc was just the opposite. It had a short snout, and large teeth with serrated edges. It was definitely a predator of large sea creatures."

The unusual fossils presented a puzzle to start with. Then Dr Pol used sophisticated software to map the features of the bones discovered on farmland in Patagonia and determine the crocodile's lineage.

His research, which is to be published in the journal Science, found that the creature belonged to the crocodile family tree.

There were many other sizes of marine crocodile species alive toward the end of the Jurassic period, but all had long snouts and needle-like teeth.

None was larger than Dakosaurus andiniensis, and none was as robust.

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

"This is the most remarkable change in the size and shape of the teeth and snout in the history of marine crocs," Mr Pol said. Zulma Gasparinini and Luis Spalletti, palaeontologists at the National University of La Plata in Argentina, uncovered the crocodile's bones. The fossilised skull measured approximately 2.5ft long. The largest teeth measured around 4in.

The three fossil specimens were found in 1996 - one on farmland in the Mendoza province of Patagonia and two in a rock formation in Neuqun province to the south. During the time that Dakosaurus andiniensis was alive, the region was a deep tropical bay of the Pacific Ocean.

The researchers do not yet know what events triggered the relatively sudden emergence of the large crocodile, but the size and shape of the teeth indicate that it probably fed on other marine reptiles and large sea creatures in the bay instead of fish.

The National Geographic Society funded the research and will feature Dakosaurus andiniensis in the December 2005 issue of the National Geographic magazine.