The discovery of claw marks in a bone-filled cave in Australia suggests an extinct, "anatomically bizarre" predator was able to climb trees and rocks, meaning it would have been a threat to humans, writes Myles Gough.
Australia's extinct marsupial lion, Thylacoleo carnifex, was the continent's top predator at the time of human arrival 50,000 years ago.
Weighing more than 100kg, the animal had sharp claws and a powerful jaw, and shearing teeth that could rip through the flesh of its prey, which included giant kangaroos, rhinoceros-sized herbivores known as diprotodon, and possibly humans.
But while experts agreed on the marsupial lion's fearsomeness, whether or not they could climb rocks and trees has been a source of contention.
Some speculated that the lions' anatomy would lend itself to climbing, while others argued they would have been too heavy to clamber up to high places.
Now palaeontologists at Flinders University say they have found the answer in a cave in Western Australia where marsupial lions left thousands of scratch marks.