Short-faced kangaroos (Procoptodon)
Short-faced kangaroos lived in Australia during the Pleistocene until at least about 50,000 years ago. There is some evidence they may have survived until 18,000 years ago. Their extinction may have been due to climate shifts in the Pleistocene (2)
The kangaroos had a flat face and forward-pointing eyes. Each foot had one large toe, similar to a horse's hoof. They used these feet to move quickly through open forests and plains to find grass and leaves to eat. Each front paw had two extra-long fingers with large claws, which may have been used to grab branches to bring leaves within eating distance. The robust skull architecture and shortened face may be related to increased masseter muscles used to chew foods. Dental microwear of P. goliah supports a browse diet, but stable isotopic data suggested its diet comprised plants using a C4 photosynthetic pathway, typically associated with grasses. In this case, chenopod saltbushes found throughout semi-arid Australia was a more likely source of the C4 signature (3).
This paraphyletic genus is derived from Simosthenurus (1). P. goliah was the largest known kangaroo that ever existed. It stood about 2 m (6.6 ft) tall and weighed about 230 kg (510 lb). P. was the smallest of Sthenurine kangaroo, standing about 1m tall.
References: 1) Prideaux (2004); 6: 1–642. Retrieved 2012-03-22; 2) "Procoptodon goliah"; 3) Prideaux et al (2009)