A study led by the Western Australian Museum has discovered two new species of extinct kangaroos that climbed trees

Two new species of extinct kangaroos that lived in Queensland rainforests have been discovered by a Western Australian Museum-led study.

Fossils of Gumardee springae and Gumardee richi, which lived between 24 and 18 million years ago, were recovered from several deposits at the Riversleigh World Heritage Area in the state's northwest.

The museum says the study is significant because it shows some members of the ancient family of fanged-kangaroos were able to climb trees, while others hopped on the ground.

"It's not well known that kangaroos have had the ability to climb trees, yet today there are several species of tree-kangaroos that live in northeastern Queensland as well as New Guinea and surrounding islands," curator of mammalogy Kenny Travouillon said.

They also had a different taste in diet, not feeding on grass like most kangaroos today.

"Some ate leaves from trees and shrubs, while others ate a wide variety of foods," Dr Travouillon said.

The new species have a set of very long teeth, much like bettongs and potoroos, which use them to chew fungi.

But while bettongs and potoroos weigh between 500g and 3.5kg, the kangaroos were a lot larger at 4-6kg.