Thursday, November 10, 2005

A Colossal Croc

At the southern tip of South America, researchers have found fossils of an entirely new species of ancient crocodile – one whose massive jaws and jagged teeth would have made it the most fearsome predator in the sea.

The fossilized skull of Dakosaurus andiniensis measures approximately 2.5 feet long. The largest teeth near the snout (on the right side of the photograph) measure approximately four inches. Photo courtesy of Diego Pol, Ohio State University.
An Unusual Marine Crocodyliform from the Jurassic-Cretaceous Boundary of Patagonia. Zulma Gasparini, Diego Pol, and Luis A. Spalletti. Published online November 10 2005; 10.1126/science.1120803 (Science Express Reports). (note: you’ll need a membership to read this.)

Unlike the crocodiles we know today, Dakosaurus andiniensis lived entirely in the water, and had fins instead of legs. But that's not all that made it unusual. Two other features – its hefty size and T. rex-like snout – have earned it a unique place in history – and the nickname “Godzilla.”

Diego Pol, a postdoctoral researcher at the Mathematical Biosciences Institute and the Department of Biomedical Informatics at Ohio State University, determined that the oddly shaped fossil specimens found in Patagonia belong on the crocodile family tree.

Photos of Dakosaurus andiniensis skull, with diagrams and a close-up view of the teeth -- including a microscopic view of one tooth's serrated edge. Figure courtesy of Diego Pol, OSU.
“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. It was definitely a predator of large sea creatures.”

Paleontologists Zulma Gasparini and Luis Spalletti of the National University of La Plata in Argentina uncovered the crocodile's fossil bones in Patagonia; Pol used sophisticated software to map the features of those bones and determine its lineage. Together, they describe the creature in the latest issue of the journal Science.

It measured 13 feet from nose to tail. Its jaws were a foot-and-a-half long, with interlocking serrated teeth up to four inches long.

Family tree of ancient marine crocodile Dakosaurus andiniensis. Figure courtesy of Diego Pol, OSU.
The National Geographic Society funded this research, and will feature D. andiniensis in the December 2005 issue of National Geographic Magazine.

The color illo is a computer rendering of Dakosaurus andiniensis which will appear in the December 2005 issue of National Geographic. Taken from HERE & © National Geographic.