Ancient Small Kangaroos That Could Not Hop Outlived Fanged Cousins

Posted on February 22, 2016

Researchers from the University of Queensland have discovered fossils of a new genus of ancient kangaroo. These small kangaroos could not hop but managed to outlive their fanged cousins. The fossils were discovered in ancient fossil deposits at the Riversleigh World Heritage Area in north-western Queensland.

The new genus has been named Cookeroo. The Cookeroo competed directly with a group of fanged kangaroos dubbed killer kangaroos. The researchers say the small, nimble kangaroos may have been better adapted to the environmental change from rainforest to more open forest and woodland.

University of Queensland researcher Kaylene Butler says in a statement, "They lived around 15 to 23 million years ago and were the size of very small wallabies or pademelons. They moved on all fours, scurrying across a densely forested landscape quite different from the dry outback we see in western Queensland today. It appears that our new species were direct competitors with a second group of kangaroos at Riversleigh, the even weirder balbarid or fanged kangaroos. It seems likely that the fanged cousins were out-competed by our new species and their descendants."

The new genus is named Cookeroo in honor of Queensland Museum researcher Dr Bernard Cooke. Two species of the genus were discovered. They have been named Cookeroo bulwidarri, which lived about 23 million years ago, and Cookeroo hortusensis, which lived 18 to 20 million years ago. A skull of the species Cookeroo hortusensis is pictured above.

A research paper on the kangaroos was published here in the Journal of Vertebrate Paleontology.

ANIMALS