The Tasmanian tiger, the extinct marsupial scientifically known as the thylacine, has gained a near-legendary status in its once-native Australia. In the popular imagination, this strangely stripped creature is sometimes pictured as a fearsome tiger-like beast that stalked the Tasmanian wilderness. However, a new study suggests this species was more like a slinky coyote-sized animal.
New research by Monash University in Melbourne has concluded that the thylacine was about half as big as once thought.
Reported in the journal Proceedings of the Royal Society B, the researchers closely studied 93 adult thylacine specimens (18 female, 23 male, 52 sex unknown), including one whole preserved body, two whole body taxidermies, three mounted skeletons, and dozens of separate body parts. Using a range of techniques and 3D analysis, they estimated that the thylacine weighed about 17 kilograms (37 pounds) on average – a stark comparison to previous estimates that stated they weighed around 29.5 kilograms (65 pounds).
Their analysis also showed strong differences in the male and female body size, with a male average of 19.7 kilograms (43 pounds) and a female average of 13.7 kilograms (30 pounds).
"We demonstrate strong differences in average male and female body size. This result also fundamentally challenges prior views about the thylacines as a carnivore, and underscores that thylacines were a predator that evolved to consume prey smaller than themselves," Dr Justin W Adams, study author from the School of Biological Sciences at Monash University, said in a statement.
The last known thylacine died in 1936 at a zoo in the Tasmanian capital of Hobart, marking the extinction of the species. Some people still report sightings of wild thylacines roaming around the Australian outback, although most experts dismiss these claims as fanciful.
Aside from a few seconds of scrappy footage from the early 20th century (below), there’s next to no evidence about thylacines' behavior and biology. So, these new findings could change a lot about what we assume about their biology. Some scientists have speculated that the thylacine perhaps behaved a lot like wolves, specialized pack-hunters that can take down prey substantially larger than themselves. However, the new sizing indicates that they were, in fact, more like a fox or a coyote that eats much smaller prey.
“We wish we could watch just how the thylacine hunted, and what sort of prey it could take – this is our closest look yet at an essential ingredient of the predator’s behavior, how big it really was,” said Associate Professor Alistair Evans, another study author from Monash University.
“Rewriting the thylacine as a smaller animal changes the way we look at its position in the Australian ecosystem – because what a predator can (and needs to) eat is very much dependent on just how big they are,” added Douglass Rovinsky, lead author of the study. “Many of the 19th-century newspaper reports just might have been ‘tall tales’ – told to make the thylacine seem bigger, more impressive… and more dangerous!”