The Canadian oil sands, a vast expanse of tar and sand being mined for crude oil, yielded treasure of another kind this week when an oil company worker unearthed a 110-million-year-old dinosaur fossil that wasn't supposed to be there.

The fossil is an ankylosaur, a plant-eating dinosaur with powerful limbs, armor plating and a club-like tail. Finding it in this region of northern Alberta was a surprise because millions of years ago the area was covered by water.

"We've never found a dinosaur in this location," Donald Henderson, a curator at Alberta's Royal Tyrrell Museum, which is devoted to dinosaurs, said on Friday. "Because the area was once a sea, most finds are invertebrates such as clams and ammonites."

The ankylosaur that was found by the oil worker is expected to be about 5 metres long and 2 metres wide.

"It is pretty amazing that it survived in such good condition," said Henderson, noting the fossil was three dimensional, not flattened by the heavy rock sediment.

"It is also the earliest complete dinosaur that we have from this province."

The fossil was found on Wednesday by a Suncor Energy shovel operator who was clearing ground ahead of development. By a quirk of fate, the worker had visited the Royal Tyrrell dinosaur museum in southern Alberta just the week before.

Henderson suggested he may have had dinosaurs on the brain. "Maybe his mind was subconsciously prepared."

Suncor has suspended work at the site and has given scientists a three-week window to remove the fossil and ship it to the Royal Tyrrell museum.

The last major fossil find in northern Alberta was a giant reptile called an ichthyosaur, which was found 10 years ago near Fort McMurray.

-Reuters