What a comparison – The Giant wombat meets the Common wombat

A convergent evolution can be observed between several Australian marsupial species and the non-marsupial mammals on other continents. Very often both groups live in similar habitats, have similar adaptations to their habitat and biology and show a similar behavior at all.
The wombats are another striking example for such a convergent evolution between marsupials and non-marsupial mammals. Wombats are remarkable beaver-like in appearance and dentition. Their feeding habits have involved a remarkable rodent-like dentition, which differs from all other marsupials. Wombats have only a single pair of upper and lower incisors and all the teeth are rootless and continuously growing.

But on the other hand they show also obvious traces of relationship to the arboreal marsupials such as possums and koalas. They have a definite affinity with the koala and might be regarded as a kind of terrestrial “native bear”. But on the other hand, wombats have become so specialized that a separate family in the zoological system is necessary for them.
All the 3 living species of wombats are nocturnal and stay the most time of the day in large burrows, which the wombat digs with his hands, normally laying on the side and thrusting the soil back with his feet. With a weight of 20-40 kg and a body length of 70-120 cm wombats belong to the larger marsupials.

But compared with their ancestors, the wombats of today are really dwarfs. In the Pleistocene the recent wombats had gigantic relatives like the herbivore Rhino wombat, which was the largest marsupial ever to have lived. The largest specimens of this group were rhinoceros-sized: about 3 m from nose to tail, standing 2 m tall at the shoulder and weighing about 2,790 to. Its feet turned inwards like a wombat’s. It had strong claws on the front feet and its pouch opening faced backwards. Footprints of its feet have been found showing a covering of hair which indicates it had a coat similar to a modern wombat. - The Rhino wombat was common in the open bush land and savannah and never strayed too far from water. They lived probably in groups and fed on leaves, twigs, bark and roots mainly of saltwort (Salsola) and other amaranths. They likely had to scarf down as much as 150 kg of vegetation daily. Their natural enemy has been probably Megalania, a large monitor of about 7 m length and an estimated weight of 1,600-1,900 kg.

Rhino wombat on the stamp and Silver coin (Click to view larger image).

Skeletal and stuffed specimen of wombat@ Ikeda city Satsukiyama Zoo(Click to view larger image).

The Rhino wombat was quite common about 26.000 years ago and still present, when the first humans arrived in Australia. Their extinction appears to have coincided with this arrival of humans on the continent. In broad terms, Rhino wombat was the largest and least well-defended species that died out. But also climate change and destruction of the ecosystem, on which the Rhino wombat depended, could be the reason for their extinction. In particular, early Aborigines are thought to have been fire-stick farmers using fire regularly and persistently to drive game, open up dense thickets of vegetation, and create fresh green regrowth for both humans and game animals to eat.
However the Rhino wombat was only distantly related to wombats and not their direct ancestor. The direct ancestors of all modern wombats was the Giant wombat (Phascolonus gigas), which can be seen as the primary wombat. The Giant wombat was much smaller than Rhino wombat, but weighted also as much as 200 kg, compared with the wombat of today really a giant. But except the size, the anatomy and biology of Giant wombats and the three recent species are very similar. The Giant wombats existed still alongside the even larger Rhino wombat and both giant marsupials disappeared at the end of the Late Pleistocene in a Quaternary extinction event together with many other large Australian animals.

Although many skeletons of Rhino wombat and Giant wombats were found, a Giant wombat or a Rhino wombat have never be seen alive. Therefore it is a real sensation that our Lost Zoo got the chance in Queensland to catch one animal, which can be seen now in the Australian corner of our Lost Zoo, just on the side of the recent Tasmanian wombat. Don’t miss this rare and gigantic species!

Executive Curator
JURGEN LANGE