In “Scientists find fossil of ancient sea monster (msnbc.comMSNBC, 7/29/2011) , Yereth \Rosen tells us, “Nearly complete skeleton is of long-tailed creature that lived in early days of dinosaurs”:
Thalattosaurs inhabited the seas for about 30 million years, a relatively brief time geologically, said Pat Druckenmiller, earth sciences curator for the Museum of the North. They measured about three to 10 feet long, with half to a third of that taken up by the tail, he said.
“We were just having our morning coffee out on the outcropping when somebody said, ‘What’s that?'”
The find includes the outline of soft body tissue, which might allow a good guess as to its shape, but they’ve yet to find the skull.
There are only about a dozen full thalattosaur specimens in the world, Baichtal said. “So the probability of this being something that wasn’t seen before is probably pretty high,” he said.