Ancient Swimming Dinosaur Kin Found in Antarctic

Dec. 11, 2006 — -- The temperature at the south pole this morning was 20 degrees below zero Fahrenheit, with blowing snow. But 70 million years ago, the waters around Antarctica were probably balmy -- with temperatures in the 50s.

New evidence of that dramatic temperature change comes from the discovery, announced today by the National Science Foundation, of the skeleton of a reptile that swam in what is now the Southern Ocean.

The fossil is of a plesiosaur, a long-necked animal with four fins. The new find is of a baby, not even five feet long from head to tail. It is one of the best-preserved skeletons of its type ever discovered.

"It's really a spectacular find," said Judd Case of Eastern Washington University, one of the leaders of the expedition that went to the Antarctic to scout for fossils. "We've never found anything this complete."

Digging the fossil up was no easy task. It was buried in the dry, windswept wastes of Vega Island, Antarctica. Vega Island is just off the Antarctic Peninsula, the part of the continent that comes closest to South America.

Today, the land is rocky and barren. Fossils go undisturbed there, mainly because it's so hard for anything else, including scientists, to survive. Winds howl at 70 mph for days on end, even in summer, with temperatures so cold that exposed water freezes in just minutes.

But 70 million years ago, Vega Island would have been heavily forested, with some of the world's first flowering plants. The steep slope where the plesiosaur was found was likely near a shoreline.

Plesiosaurs were technically not dinosaurs. Scientists say they had more in common with modern sea turtles and snakes.

"All we know is they lived and died in an environment that was much different than ours today," said Jim Martin of the South Dakota School of Mines, who joined Case on the expedition.

Plesiosaurs have been found in England and Scandinavia. They may have been plentiful throughout the world's oceans during the Cretaceous Period, when tyrannosaurrus rex roamed the land.