BROAD SHELLED TORTOISE Chelodina expansa Gray, 1857
This large tortoise attains 50 cm in length. Found in coastal southeast Queensland, including Fraser Island, and the Murray Darling river system.
Specimens from the Murray Darling system have very flattened shells, whilst those from coastal Queensland, (usually the Burnett River System) have a deeper shell (pictured in this book), as do older specimens from elsewhere.
It is typified by its' extremely long neck and flattened head, and is the largest long necked species. This tortoise is essentially only a river species, although around Moonie in Queensland, specimens appear to make large overland journeys when it rains. This species strikes at its' food in a manner not unlike that of a snake striking its' prey from a coiled position. Captive specimens are known to have fed on small chickens and mice, as well as more 'typical' foods.
The large hard-shelled eggs when laid in late summer and autumn appear to take nearly twelve months to hatch. Hatchlings measure about 3.5 cm in length, but can more than double this size within twelve months if well fed.

The above was from the book Australian Reptiles and Frogs by Raymond Hoser and now available on a fantastic CD-Rom along with a vast amount of other information, papers and the like on reptiles, frogs and other wildlife.