VANCOUVER -- Workers removed fossil remains from the banks of the Trent River on Vancouver Island Saturday, safely extracting them from where they had been resting for 85 million years.

"We brought down a plaster jacket," said Pat Trask, natural history curator for the Courtenay and District Museum and Paleontology Centre. "It was up a cliff 35 feet up in the air and it was the rib cage of a plesiosaur."

Trask believes the fossilized ribs are from a marine reptile, but he won't know exactly which species unless he recovers more of the specimen and is able to piece it together.

He says it's possible the bones are of an elasmosaur, one of which his brother Mike discovered near the same spot back in 1988.

Trask has been finding various bones along the Trent River over the last three years, but the latest discovery was a special one. Four weeks ago, he noticed a bone at the base of a cliff that seemed to be pointing to the rib cage above.

"It was pretty amazing to see them from the ground," Trask said. "It looked like bones, even with the naked eye, I can see them sticking out of that cliff."

What followed were many sleepless nights spent worrying about the safety of the fossils.

"I couldn't sleep," he said. "I knew the bones were sticking out of that cliff and people could see them from the ground. And I'm like, 'Uh oh, somebody don't take a big stick and start poking at that.'"

Trask calculates he has now recovered roughly 60 per cent of the creature, which he believes is about the same size as a model elasmosaur on display at the museum.

"I'm pretty excited, because if there's a skull there, we can figure out what it is and maybe get it named, and if it's an elasmosaur, it will fit in with the provincial fossil," he said.

In the meantime, with the plaster jackets excavated Sunday now safely inside the museum, Trask and his colleagues will be busy marrying the new fossils with those previously found, in hopes that the mystery creature can finally be identified.

With files from CTV News Vancouver Island's Gord Kurbis