Some 90 years after the death of the last documented thylacine – better known as the Tasmanian tiger – the species remains a global symbol of human-made extinction. The carnivorous marsupial fell victim to 19th-century colonists’ perception that unfamiliar creatures were primitive, vermin-like imitations of more familiar European animals. The species was later exterminated due to sensationalist claims that it was a ferocious, wolf-like predator of sheep.However, our new study, published in Nature Communications, suggests the thylacine defied the colonialists’ assumptions in every way. It was unique among modern predatory mammals by subduing its prey with high-impact snaps of slender, oversized jaws.Our focus was on one of the most widely cited cases of evolutionary convergence – the dog-shaped skull of the thylacine, which inspired its species epithet cynocephalus (“dog-head”). This is a striking similarity as thylacines are separated from dogs by more than 120 million years of evolution. So we set out to understand how deep the similarity really goes. Overview over the mammalian tree of life with thylacine in pink and wolf in orange. Modified from work by OrthoMaM: A database of orthologous genomic markers for placental mammal phylogenetics. Ranwez et al. (2007), CC BY-SA A massive head with a flimsy faceWe used 3D shape analysis to compare scanned thylacine skulls from museums around the world with those of other predatory mammals. This revealed that different regions of the thylacine’s skull resemble those of several other animals.The thylacine’s long and thin snout looks pretty fragile, most like that of small foxes and jackals. By contrast, the back of the thylacine’s skull resembles that of wolves, dingos and dholes (also known as the Asiatic wild dog).But the standout feature of this odd patchwork was the thylacine’s enormous head. Its relatively puny 17 kilogram body carried a skull as large as that of wolves, which are more than twice the thylacine’s weight.So why this skinny jaw on an outsized head? We suspect this combination allowed thylacines to subdue their prey with powerful snapping bites. Thylacine jaws are clearly built for speed: the longer a jaw is, the faster its tip moves during biting. Combined with the animal’s famously large gape, this should increase the impact of the strike. Long jaws like this are usually quite weak, but the huge size of the thylacine’s skull would have added enough substance to withstand lethal snaps into potentially unsuspecting bandicoots. A yawning thylacine at Beaumaris (now Hobart) Zoo taken in 1933. Dr David Fleay The mammalian answer to crocodiles?But it is the features that are not found in other predatory mammals that may have taken the thylacine’s snaps to a new deadly level. The thylacine’s upper jaw is exceptionally tall, with a distinctive “pinched” hourglass shape at the tip. This combination is perfect for resisting the stress of high-impact, upwards-directed bites. It also matches earlier results that thylacine canine teeth seem most suited to puncturing, crushing bites (rather than pulling, tearing, or holding).Thylacines were probably the last modern predatory mammals to sport such a tall, mace-like snout. But similar jaw types are found across other vertebrates, such as crocodiles, and are usually interpreted as adaptations for hunting fast-moving prey. But some extinct mammals also had thylacine-like snouts, most notably in the gigantic extinct predator Andrewsarchus. Our results are particularly tantalising in view of earlier genomic work which suggested that natural selection acted on regulatory genes in some shared developmental pathways of wolves and thylacines. It is possible these genomic similarities are behind some of the shared aspects of skull shape between wolves and thylacines. However, as we know wolves and thylacines did not fill the same ecological niche, we might ask how these genomic convergences produced such a uniquely specialised marsupial predator. Even though wolves, thylacines and red foxes are separated by millions of years of evolution, their skulls show striking similarities. Vera Weisbecker A lesson for urgent and thoughtful future scienceOur results highlight – yet again – that the thylacine’s eradication targeted an animal that only existed in the early colonial imagination. But they are also a timely reminder we cannot afford to repeat this mistake through negligence. Australia has the worst mammal extinction rate in the world. Its wildlife faces escalating threats from environmental degradation, climate change, and new threats such as bird flu. Museum-based research like ours is needed to illustrate how these statistics reflect irreplaceable biodiversity lost with every extinction.But we also need to remember Western science is only part of the story – respectfully requesting knowledge from Indigenous custodians about the unique Australian wildlife should be key to our future research. After all, the people who lived alongside thylacines for tens of thousands of years knew exactly what kind of animal it was.Vera Weisbecker receives funding from the Australian Research Council. She is a member of the Australian Mammal Society and the Australian Greens Party.Andrew Pask receives funding from the Australian Research Council, National Health and Medical Research Council and Colossal Biosciences. Douglass S Rovinsky does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.