Temporal range: Pleistocene
Procoptodon was a genus of giant short-faced kangaroo living in Australia during the Pleistocene epoch. P. goliah, the largest known kangaroo that ever existed, stood approximately 2 m (6.6 ft). They weighed about 230 kg (510 lb). Other members of the genus are smaller, however, and Procoptodon gilli is the smallest of all of the sthenurine kangaroos, standing ~1m tall.
Giant short-faced kangaroos had a flat face and forward-pointing eyes. On each foot they had a single large toe somewhat similar in appearance like a horse's hoof. On these unusual feet they moved quickly through the open forests and plains, where they sought grass and leaves to eat. Their front paws were equally strange: each front paw had two extra-long fingers with large claws. It is possible that they were used to grab branches, bringing leaves within eating distance. Their robust skull architecture and shortened face has been thought to be related to increased masseter muscles used to chew foods. Dental microwear of P. goliah supports a browse diet; however, stable isotopic data suggested its diet consisted of plants utilising a C4 photosynthetic pathway, typically associated with grasses. In this case, however, chenopod saltbushes found throughout semi-arid Australia were considered a more likely source of the C4 signature.
The genus was present until at least about 50,000 years ago before going extinct, although there is some evidence they may have survived to as recently as 18,000 years ago. Its extinction may have been due to climate shifts during the Pleistocene, or to human hunting.
Fossils of giant short-faced kangaroos have been found at the Naracoorte World Heritage fossil deposits in South Australia, Lake Menindee in New South Wales, Darling Downs in Queensland, and at many other sites. A full-size, lifelike replica is on permanent display with other ancient native Australian animals at the Australian Museum.
Unlike modern kangaroos, which are plantigrade hoppers at high speeds and use their tails in pentapedal locomotion at slower speeds, Procoptodon was an unguligrade biped, walking in a fashion similar to hominids.
- Haaramo, M. (2004-12-20). "Mikko's Phylogeny Archive: Macropodidae - kenguroos". Retrieved 2007-03-15.
- "Procoptodon goliah". Australian Museum. Retrieved 2012-03-22.
- Helgen, K.M., Wells, R.T., Kear, B.P., Gerdtz, W.R., and Flannery, T.F. (2006). "Ecological and evolutionary significance of sizes of giant extinct kangaroos". Australian Journal of Zoology 54 (4): 293–303. doi:10.1071/ZO05077.
- Prideaux, G. J.; Ayliffe, L. K.; Desantis, L. R. G.; Schubert, B. W.; Murray, P. F.; Gagan, M. K.; Cerling, T. E. (2009-07-14). "Extinction implications of a chenopod browse diet for a giant Pleistocene kangaroo". Proceedings of the National Academy of Sciences 106 (28): 11646–11650. doi:10.1073/pnas.0900956106.
- Prideaux G (2004). "Systematics and Evolution of the Sthenurine Kangaroos". University of California Publications in Geological Sciences 146: 1–642. Retrieved 2012-03-22.
- Janis, CM; Buttrill, K; Figueirido, B (2014). "Locomotion in Extinct Giant Kangaroos: Were Sthenurines Hop-Less Monsters?". PLoS ONE 9 (10). doi:10.1371/journal.pone.0109888. Retrieved October 15, 2014.
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