Two trail bike riders claim to have discovered what could be the skull of a tasmanian tiger while filming during a ride through bushland.

The skull is being scientifically evaluated this morning.

Brothers Levi and Jarom Triffitt are members of the Tassie Boys, a group of stunt trail bike riders based in central northern Tasmania.

They say they were riding in bushland last week while filming stunts for a promotional video when they came across the skull.

They say it is unlike anything they have ever seen before, and closely resembles the skull of a thylacine.

"Lot's of people think 'dog', but when you actually get on Google and compare it to your normal dogs that are in Tasmania, the closest thing we could find it to was an American timber wolf, which I don't believe we have here," Jarom said.

The last known tasmanian tiger died in the Hobart Zoo in 1936.

Levi denies the find is a hoax.

"We were just having a regular day - just doing some photography and filming," he said.

The brothers plan to have the skull checked in Launceston this morning.