Wombats are truly unusual amongst the already bizarre Australian marsupials. They are the only group to have have ever-growing molars- a trait that helps them process the abrasive grasses they eat without wearing their teeth down to useless stubs. They are also the only large-bodied marsupial to burrow but the story doesn’t end there.
Wombats were previously much more diverse than they are today and the three surviving species (Vombatus ursinus, Lasiorhinus latifrons and L. krefftii) are amongst the smallest members of the Pleistocene wombat radiation. The largest member of the family, Phascolonus gigas, was around a metre tall, weight 150-200kg and may still have burrowed. It went extinct along with most of the Australian megafauna around 40 thousand years ago, well after humans had established their presence across the continent.