A giant with a short face
During the Pleistocene epoch, Australia had Procoptodon goliath, the largest kangaroo known to have existed. This giant stood up to 2.7 meters (nearly 9 feet) tall and weighed as much as 240 kilograms (530 pounds), almost three times the size of the largest kangaroos alive today. Its fossils are found across semi-arid regions of Australia, from Darling Downs in Queensland to the Naracoorte Caves in South Australia.
Unlike modern kangaroos, Procoptodon had a distinctively short, flat face with forward-pointing eyes. This anatomy provided binocular vision, a useful trait for judging distances while moving through woodlands. Its skull was heavily built, supporting powerful chewing muscles to process a diet of tough leaves and stems. The forelimbs were also unusual, featuring two elongated fingers with large, curved claws that likely served as grappling hooks to pull high branches within reach.
A stride, not a hop
The locomotion of Procoptodon goliath is a subject of scientific debate. Its immense body mass and rigid lumbar spine would have made the energetic, repetitive motion of hopping difficult. Biomechanical analysis suggests that sustained hopping was likely impossible for an animal of this size. Instead, it may have adopted a bipedal striding gait, walking on two legs in a manner similar to hominids.
This theory is supported by its specialized anatomy. Its hips and ankle joints were broad and adapted to resist twisting, which is consistent with supporting its full body weight on one leg at a time. Each hind foot had a single, massive toe, a condition known as monodactyly, which functioned somewhat like a horse's hoof. This structure, combined with large buttocks, shows an animal built for walking, not hopping. This unique kangaroo disappeared around 45,000 years ago, along with many of Australia's other megafauna.