Diprotodon and Zygomaturus
Diprotodon, the largest marsupial that ever lived, looked somewhat like a long-legged wombat. It occurred over most of Australia, apart from in the extreme south-west and in Tasmania.
Most examples of the skulls of this animal have been crushed in the fossilisation process because they are remarkably thin compared to those of similar-sized mammals such as the rhinoceros.
Rare exceptions are found in the museum’s collection from Bacchus Marsh, where unusual preservation provides information about internal structure as well as external form. The internal structure shows that Diprotodon evolved unique ways to minimise the weight of the skull and the amount of bone that was necessary to form it, factors that might have given it a competitive edge in surviving in a nutrient-poor environment.
The large marsupial Zygomaturus was restricted to south-eastern and south-western Australia, unlike its close relative the more widely ranging Diprotodon. This reflects the preference of Zygomaturus for lush, forested habitats in contrast to the open plains and arid regions favoured by Diprotodon.
The two were four-footed herbivores that might have overlapped in their dietary preferences with the larger kangaroos. Competition with the kangaroos for food might have contributed to the extinction of Zygomaturus and Diprotodon.
A Zygomaturus skeleton was donated to the museum early in the 20th century by the Queen Victoria Museum and Art Gallery in Launceston, Tasmania. Staff from that museum collected the specimen from Mowbray Swamp near Smithton, Tasmania, aZygomaturus graveyard that has produced the most complete skeletons of this animal.