Charles M. Russell National Wildlife Refuge

Prehistoric Sea Creature Fossil Found on Wildlife Refuge

January 24, 2011, 8:02 am

Charles M. Russell National Wildlife Refuge in Montana is renowned as a dinosaur fossil site, but the discovery of a prehistoric sea creature called a plesiosaur on the refuge has scientists particularly intrigued.

"We kind of base our level of excitement on how excited the paleontologists get, and they're definitely excited about this one," says acting Refuge Manager Bill Berg.

A bow hunter found the remains on the refuge last fall,  in approximately 75-million-year-old dirt and rock. Part of the neck, which Berg estimates weighs 800 to 900 pounds, had been exposed by erosion. Refuge staff "went back in there and covered it up with loose material to keep it from weathering more than it has," says Berg.

Much of the rest of the plesiosaur's body is believed to be encased in rock formations. This spring, Berg says, refuge staff will take a Museum of the Rockies paleontologist to the site to make a scientific evaluation of the specimen.

Numerous scattered triceratops and tyrannosaurus rex fossils have been found on the 1.1 million-acre refuge, which was once an inland sea, but a potentially intact plesiosaur is rare, Berg says. Like modern-day whales, plesiosaurs were air breathers. They propelled themselves in the sea using their four paddles, catching fish and other prey with well-toothed jaws on the end of long necks. The largest plesiosaurs were 40 feet long and had nearly 70 neck vertebra. The specimen at Charles M Russell Refuge is believed to have from 19 to 26 neck vertebra.