Phascolarctos cinereus photo © Dilliff
                                

Koala is eucalypt-hyrax rather than Antipodean sloth

Phascolarctos cinereus mounted skeleton photo © Sklmsta

The koala is often compared with the tree sloths of the Americas, which are also arboreal, leaf-eating, sleepy, small-brained, and slow in metabolism and growth. However, the skull of the koala is not nearly as peculiar as those of tree sloths, being much more convergent with those of the African tree hyraxes. Given the extreme specialisation of the koala on the tough leaves of Eucalyptus, and the considerable difference in modes of climbing and reproduction between the koala and tree hyraxes, it is surprising that both types of animals eat their staple diet of tree leaves with similar cheek-teeth.

Robin and the Honey Badger, 8 January 2017
 

Photographs:
Koala
Phascolarctos cinereus
Tree hyraxes
Dendrohyrax sp.
Tree sloths
Bradypus variegatus

 

Bradypus variegatus photo © Stefan Laube