Kangaroos a high point in evolution

Credit: Rich Childs
Credit: Rich Childs

People who live outside Australia often regard kangaroos as strange, specialised, relic animals. Not so, says palaeontologist Dr Ben Kear at La Trobe University in Melbourne.

They represent a high point in mammal evolution, he says, a generalised body plan that has adapted to a wide variety of environments, from rainforest to deserts, from rocks to trees. ”Some may even have been carnivores.”

Ben and his colleagues have recently been integrating all the information—from bone specimens to DNA—that has been gathered on the 70 living species and similar number of extinct kangaroos.

Their data shows a diverse group of marsupials which has adapted to, and thrived, in all that climate change has thrown at it as the Australian continent went from being wet to increasingly arid.

Ben has a particular interest in the earliest fossil species, Nambaroo gilespieae, which lived about 25 million years ago. The Nambaroo was the size of a small dog and adapted to life in a tropical forest. Its hind limbs show that it probably did not even hop, but bounded on all fours like a possum.

For more information: Genetics Department, La Trobe University, Ben Kear, Tel: +61 (3) 9479 2267, b.kear@latrobe.edu.au