Last December an 8-second amateur video went viral. Shot in remote northern Tasmania, the blurry footage featured a long-tailed mammal trotting across a meadow with an oddly stilted gait. According to the film-maker, Murray McAllister, the animal was a Tasmanian tiger.

The Tasmanian tiger, or thylacine, is a wolf-sized marsupial predator that has been presumed extinct since the last known specimen died in Hobart zoo in 1936. Yet despite its apparent demise, reports of Tassie tigers refuse to die. Hundreds of sightings, many from seemingly credible observers, have been recorded, both in Tasmania and on the mainland.

When I saw the video there was something vaguely familiar about it. Then it hit me: the animal moved like a red fox. I'd raised a fox as a boy in the western US, and they have a peculiar way of trotting. Soon, others were saying the same thing. Then a faecal sample McAllister collected was analysed for its DNA: it was a red fox.

McAllister has been searching for the Tasmanian tiger since 1998. Though he might not describe himself as such, he is a cryptobiologist, a chaser of mythical, mysterious or supposedly extinct species. Cryptobiologists are a diverse lot, ranging from conventional scientists to eccentrics far from the mainstream. All share a dream of discovering elusive or unknown creatures unrecognised by conventional science - and with it their share of instant fame.

To read the rest of the article, click here.