September 7, 1936, is widely considered the day the world's last remaining Tasmanian tiger died at Hobart's Beaumaris Zoo but a new study reveals its ancestors might have survived to the 1980s - or later - in the wilderness.
And there is a "small chance" it might still live on in remote areas.
A team of international researchers has shed new light on the extinction of the thylacine, or Tasmanian tiger, one of the most iconic and mysterious animals of the 20th century.
The study, led by University of Tasmania professor of environmental sustainability Barry Brook, used a comprehensive database of 1237 observational records from Tasmania, dating from 1910 onwards, to map the species' decline and eventual extinction.
"We found that the thylacine's distribution shrank rapidly after a period when bounties were provided for animal skins across Tasmania (1888-1909), and that the most likely location of the last surviving subpopulation was in the south-western region," Prof Brook said.
The team also estimated the most likely extinction date for the species, using uncertainty modelling and sensitivity analysis.
"The results showed that extinction likely occurred within four decades after the last capture, so around the 1940s to 1970s.
"But we found, through further analysis, that extinction might have been as recent as the late 1980s to early 2000s, with a very small chance that it still persists in the remote south-western wilderness areas."
Prof Brook said this study provided the most comprehensive and rigorous analysis of the thylacine's extinction to date.
"We used a novel approach to map the geographical pattern of its decline across Tasmania, and to estimate its extinction date after taking account of the many uncertainties.
"Our findings not only shed new light on the fate of this iconic species, but also demonstrate a useful method for conservation prioritisation and search efforts for other rare species of uncertain status."
Co-author Dr Stephen Sleightholme from the International Thylacine Specimen Database said the thylacine was one of the most fascinating and enigmatic animals of modern times.
"It has captivated the public's imagination for decades and inspired many efforts to prove its ongoing existence. Our study shows that there is still much to learn about its history and ecology."