Your Daily Fossil

Apr 6

Procoptodon - The giant short faced kangaroo 

Mounted skeleton on display at Victoria Fossil Cave, Naracoorte Caves National Park, South Australia

Reconstruction by Peter Trusler. 

When: Pleistocene (~ 2 million to 15,000 years ago)

Where: Throughout Australia

What: Procoptodon is a giant fossil kangaroo. Exactly how ‘giant’ it is has been a bit exaggerated, heights of up to 10 feet (~3 meters) have been reported, but this would have been its maximum height when it reared up fully on its hind legs, with its arms reaching up for high branches. Procoptodon was capable of this posture, but (like living kangaroos) it did not stand fully upright most of the time. In its normal feeding (and most everything else) poster it would have stood about 6.5 feet (~ 2 meters) tall; about the same height as the largest of the modern red kangaroos. Procoptodon was not the same size as these animals though, it was much more massive and would have been over twice the weight of a red kangaroo of equivalent height. 

Procoptodon was very well adapted for the semiarid conditions that characterized much of Australia during the Pleistocene, but fossil remains have also been found in the more hospitable regions of prehistorical Australia.  The marsupials of Australia are well known for their convergence evolution upon forms from other continents (such as the tasmanian tiger and the marsupial mole), but the kangaroo does not look like any placental mammal known. However, in terms of its lifestyle, the ecological niche that it inhabits, the group is convergent upon hoofed animals, such as deers!  Procoptodon overlapped with human habitation of Australia, and it is thought some Aboriginal folktales are about this massive kangaroo. 

Procoptodon is a member of the group Sthenurinae - the shortfaced kangaroos. As you probably guessed these kangaroos had much shorter snouts than the modern species of kangaroos. This group is completely extinct. It is one of the subgroups of the Macropodidae, the clade of marsupials that contains all kangaroos and wallabies, as well as a few other  groups. It has been proposed that within the Macropodidae the closest living relative of Procoptodon is the Banded hare-wallaby, though this is not universally accepted. 

In the prehistoric outback Procoptodon would have co-exsited with the largest marsupial of all time Diprodoton and was a hunted by the marsupial lion ThylacoleoAnd the second link you can see this marsupial predator hunting a close relative of Procoptodon!