Diprotodon optatum

Diprotodon optatum

Where did they live?
Diprotodon fossils have been found in many sites across Australia, including the Darling Downs in southeastern Queensland, Wellington Caves, Tambar Springs and Cuddie Springs in New South Wales, Bacchus Marsh in Victoria and Lake Callabonna, Naracoorte Caves and Burra in South Australia.

What was their habitat?
They preferred semi-arid plains, savannahs and open woodlands, and don’t seem to have strayed far from water. They seem to have been generally absent from hilly, forested coastal regions.

What is special about them?
The Diprotodon, an ancient hippo-sized, wombat-like mammal, are the largest marsupials ever found –anywhere. And they are Australia’s very own. They date back to the Pleistocene Epoch. They may have been the ‘bunyips’ of Aboriginal Dreamtime legend as some tribes make this connection having seen the fossils.

What did they eat?
As herbivores, they were probably browsers, feeding on shrubs and herbs growing in fields and may have eaten as much as 100 to 150 kilograms of vegetation daily. Their chisel-like incisors may have been used to root out vegetation.

How did they reproduce?
The Diprotodon fossils reveal one sex, probably the male, was considerably larger than the other. There was, therefore, a high degree of structural difference between the sexes, known as 'sexual dimorphism'. In sexually dimorphic mammals the male usually breeds with many females during the breeding season and this is a strategy possibly used by the Diprotodon. Female skeletons have been found with babies located where the pouch would have been.

What else do I need to know?
Diprotodons were heavily built, large-bellied quadrupeds (four-footed animals). Their oversized skulls were lightweight and filled with numerous air spaces. They had two forwardly directed lower incisors. They weighed up to 2800 kilograms and were just under four metres in length.

Where do they fit on the tree of life?
Species: optatum
Genus: Diprotodon
Subfamily: Diprotodontinae
Family: Diprotodonidae
Order: Diprotodontia
Magnorder: Australidelphia
Cohort: Marsupialia
Infralegion: Theria
Sublegion: Boreosphenida
Division: Theriiformes
Superdivision: Theriimorpha
Infraclass: Holotheria
Subclass: Mammaliaformes
Class: Mammalia
Superclass: Tetrapoda
Subphylum: Vertebrata
Phylum: Chordata
Kingdom: Animalia

What is their conservation status?
The Diprotodon optatum is extinct.