The remarkably well-preserved fossil of a dinosaur-era sea creature found in a Canadian mine is turning out to be a gold mine for paleontologists. The Cretaceous-period reptile, dubbed Nichollsia borealis, is not only a new species—it represents a whole new genus. It’s also one of the oldest and most complete plesiosaur fossils ever unearthed in North America.

Plesiosaurs were carnivorous reptiles that roamed the seas between about 205 million to 65 million years ago.

The fossil ended up at the Royal Tyrrell Museum in Drumheller, Alberta, where University of Calgary paleontologists Patrick Druckenmiller and Anthony Russell recently ran 3-D CT scans of its braincase.

The scans and other analyses of the reptile have provided more detail than for any other plesiosaur ever found, they said.

The newfound reptile also gave them a window into an ancient seaway that once cut through North America and teemed with marine life.

[VIA]