The response to a chance discovery of a supposed thylacine skull shows man still loves the idea of an animal it wiped out last century.

Deloraine brothers Jarom and Levi Triffitt made the ''discovery'' on Friday.

The trail bike riders found the skull near the Great Western Tiers around Mount Roland in the Gog Ranges.

''Levi walked up and joked, `look what I've found, a thylacine', and as we looked at it, it got us a bit excited,'' Jarom said.

The brothers posted a video of their find online and were ''flat out'' fielding interest in the story ever since.

The story ended yesterday at the Queen Victoria Museum and Art Gallery in front of an excited media throng.

It took museum staff Tammy Gordon and Craig Reid just a few minutes to declare it a dead dog's skull, which is ''superficially, almost identical''.

''It would be easy for most people (to make the mistake) because they're very, very similar having evolved from a similar lifestyle,'' Ms Gordon said.

The collection officers used differences in the skull's palate and nasal bones to distinguish it from a thylacine's.

Ms Gordon said people occasionally brought skulls to the museum in the hope they were thylacines.

They usually turned out to be from a dog or sometimes a wombat, she said.

''It's a good thing that they do bring them in . . . there is always the chance, the very remote chance, that one day they might bring in something important like a thylacine skull,'' Ms Gordon said.

The last genuine thylacine skull found in the wilderness occurred before the last known Tasmanian Tiger, Benjamin, died in Hobart Zoo in 1936.

''There's something I think in all of us that hopes the thylacine isn't extinct,'' QVMAG director Richard Mulvaney said, in summing up yesterday's disappointment.

For the Triffitt brothers the hope continues.

''They weren't sure about the front teeth of the thylacine so it leaves a bit of thought there I guess,'' Levi said.