Australian dinosaurs are known mostly from fragmentary fossils, although these show that Australia had a unique, diverse high-latitude dinosaurian fauna. New discoveries of relatively complete dinosaurs from Queensland, however, are putting Australia on the global dinosaur map and opening up a ‘new frontier’ for dinosaur research.
Fragmentary fossil record
The Australian dinosaur record has long been an intriguing puzzle, but with most of the pieces missing. Australian dinosaurs are known mostly from fragmentary fossils, largely because of a lack of dinosaur-bearing rocky outcrops from the Mesozoic (The 'Age of Dinosaurs').
Most dinosaurs found in eastern Australia
Most Australian dinosaurs come from the eastern half of Australia (Queensland, New South Wales and Victoria) although isolated dinosaur bones have been found in Western Australia and South Australia.
Dinosaur bones from Lightning Ridge in New South Wales have been uniquely preserved in opal, generally as casts of the original bone.
A Gondwanan heritage
Australian dinosaurs lived ‘on the edge’ at the far eastern end of East Gondwana, which at the time lay well to the south of Australia’s present position. The climate would have been temperate and humid, perhaps with winter snow and ice in areas of southern Victoria, and many parts of Australia would have experienced the extremes of daylight found in high latitudes today. Much of central Australia was submerged under a shallow inland (‘epicontinental’) sea, leaving the higher areas as large but isolated islands for much of the Cretaceous. This unusual habitat along with Australia’s geographic isolation during the latter part of the Mesozoic meant that many of Australia’s dinosaurs evolved as unique species adapted to extreme conditions.
Very recent discoveries
Over the past year, the Australian dinosaur record has taken a quantum leap forward. The back-breaking effort put into searching the paddocks of outback Queensland for dinosaurs is producing spectacular results, and three new dinosaurs - the theropod Australovenator and the sauropods Wintonotitan and Diamantinasaurus - have just been described from Queensland’s mid-Cretaceous Winton Formation. Revisions are also underway on other Australian dinosaurs.
Overturning old ideas
This new research is bound to provide fresh insights into Australia’s past and will almost certainly overturn earlier ideas about what dinosaur groups were present in Australia, where these groups first originated and who their closest relatives are.
Watch this space!
Dr Anne Musser , Palaeontologist