ANCHORAGE — Researchers have confirmed the discovery of a marine reptile fossil in the Talkeetna Mountains, the University of Alaska Museum of the North announced Wednesday.

Fossil bones of an elasmosaur (ee-LAZ’-moh-sohr), a type of plesiosaur (PLEE’-see-oh-sohr), were found by Anchorage-based fossil collector Curvin Metzler.

Elasmosaurs had extremely long necks and limbs like paddles that allowed them to swim underwater, Patrick Druckenmiller, the museum’s earth science curator and a marine fossil expert, said in the announcement.

“Picture the mythical Loch Ness monster and you have a pretty good idea what it looked like,” he said.

The species lived about 70 million years ago during the Late Cretaceous period. The marine reptiles lived during the age of dinosaurs but are not classified as dinosaurs because they did not walk on land or fit other dinosaur criteria, museum spokeswoman Theresa Bakker said.

The fossils are the first from an elasmosaur in Alaska.

Over several years, Metzler found vertebrae eroding from a bluff. Metzler, Druckenmiller and two others visited the site in June, identified the source of the bones and collected much of the skeleton.

Druckenmiller has collected plesiosaurs from all other parts of western North America and in 2010 led a team that collected a nearly complete elasmosaur skeleton from Montana. The skeleton is on display at the museum in Fairbanks.

“I was really excited the first time Curvin showed me one of its bones,” Druckenmiller said. “I recognized it as a vertebra from the base of the animal’s neck and wanted to visit the site to see if we could find more. Based on the size of the bones we excavated, the animal should be at least 25 feet long.”

The fossils were halfway up a 60-foot cliff.

“We got a good chunk of the animal, but there is still more to excavate,” Druckenmiller said.

Two other ancient marine reptile fossils have been identified in Alaska: a dolphin-like ichthyosaur found in the Brooks Range and southeast, and the thalattosaur, which looked like a long lizard with a flattened tail, discovered near Kake.