Flexible shoulders hint that a sizable and now-extinct marsupial could manoeuvre through the branches.
A large kangaroo climbing a tree might sound roo-diculous today. But tens of thousands of years ago, some bulky kangaroos were indeed adapted to arboreal life, according to new research.
Most modern macropods ― a marsupial family that includes kangaroos and wallabies — stick to the ground, but a few medium-sized species spend nearly all of their time in trees. Natalie Warburton at Murdoch University in Perth and Gavin Prideaux at Flinders University in Adelaide, both in Australia, analysed skeletal remains of the extinct macropod Congruus kitcheneri, found in southern Australia.
Standing at around one metre tall and weighing about 50 kilograms, C. kitcheneri was smaller than some of its extinct giant relatives, but larger than most living marsupial species. Unlike its big-framed cousins, C. kitcheneri had a particularly mobile shoulder joint, large hands and feet with curved claws, and arm muscles specialized for drawing the forelimbs towards the body.
These physical traits suggest that C. kitcheneri was able to climb and move slowly through trees, although it wasn’t as specialized for arboreal living as modern tree-kangaroos, the researchers say.