Marsupial lion
The animal was robust with powerfully built jaws and very strong forelimbs. It had retractable claws, unique among marsupials. This allowed the claws to remain sharp by protecting them from wear when walking. The claws were well-suited to holding prey and for climbing trees. The first digits ("thumbs") on each hand were semi-opposable and bore an enlarged claw. Palaeontologists believe that this would have been used to grapple with its prey, and gave a sure footing on tree trunks and branches. The hind feet had four functional toes, the first digit being much reduced in size but possessing a roughened pad similar to that of possums. It may have assisted with climbing. It is unclear whether the marsupial lion had syndactyly (fused second and third toes) like other diprotodonts.