North America's oldest aquatic reptile fossil found

BEIJING, March 25 (Xinhuanet) -- A fossil uncovered by commercial miners in Canada has brought to light one of the oldest, most complete skeletons of a prehistoric aquatic reptile in North America. It represents an entirely new group of plesiosaurs, paleontologists say.

Plesiosaurs are not classified as dinosaurs, but these reptiles swam in the seas at the same time that dinosaurs roamed the land throughout the Jurassic and Cretaceous Periods about 205 million to 65 million years ago.

The new specimen is an 8.5-foot (2.6-meter)-long plesiosaur named Nichollsia borealis in memory of the late renowned paleontologist Elizabeth (Betsy) Nicholls. Nicholls was credited with transforming the understanding of prehistoric ocean life by describing the largest-ever marine reptile, a 76-foot (23-meter)-long ichthyosaur, discovered in northern British Columbia in 1999.

The fossil was uncovered in 1994 by machine operators in a Syncrude Canada Ltd. mine in the northeastern part of Alberta. The description of the fossil was not published until now because fossils take a long time to prepare; the rock they were embedded in must be removed before they can be properly studied.

"This is a great tribute because Betsy worked on many of the fossils recovered by Syncrude over the years, and this specimen is a direct result of the connection she had with the company for many years," said Nicholl's husband, Jim Nicholls, a retired University of Calgary professor. "We are very proud that her work will be remembered in the scientific record in this way."

Plesiosaurs were a diverse group of aquatic carnivores that reached lengths of more than 39 feet (12 meters). Nichollsia lived about 112 million years ago, and the specimen fills in a 40-million-year gap in the plesiosaur fossil record.

University of Calgary researchers studied and formally described the newly announced plesiosaur specimen in the current issue of the German research journal Palaeontographica Abteilung A.

The fossil was uncovered by one of Syncrude's 100-ton electric shovels about 197 feet (60 meters) below the surface of the ground. The skeleton was complete except for its left forelimb and shoulder blade, making it one of the most complete and best-preserved North American plesiosaurs from the Cretaceous Period.

(Agencies)