 |
| Photo courtesy University of Queensland |
The discovery in Queensland of the ancestor of all modern crocodilians highlights the fact that many key groups of animals may have originated right here in Australia, according to Dr Steve Salisbury.
Crocodilians include alligators, caymans, gharials and, of course, crocodiles.
Earlier this year Dr Salisbury, a lecturer in Integrative Biology at the University of Queensland, announced the discovery of Isisfordia duncani (named after Isisford in far western Queensland where the fossils were found, and local farmer Ian Duncan, who found the first of them).
This small crocodilian - about 1.1 metres in length and weighing three or four kilograms - is the first of its family to have two of the most important characteristics of its modern descendants. Dr Salisbury is pictured with the ancient fossil.
Isisfordia had ball and socket joints between their vertebrae, which gave them a very strong backbone, and a hard palate which reached to the back of their mouths and gave them the second strongest bite ever known - second only to that great carnivore, Tyrannosaurus rex.
Dr Salisbury said discoveries from the age of the dinosaurs now being made in this state are very important.
"They are finally beginning to paint a picture of what life was like here during the age of the dinosaurs and they are providing us with important information about the nature of Gondwana's dinosaur fauna," he said.
Gondwana was the super continent that included most of today's Southern Hemisphere land masses, plus Arabia and India. It began to break up about 167 million years ago.
"Being an isolated peninsula on the eastern extremity of Gondwana, Australia may have acted as a type of evolutionary crucible for many groups that later spread out around the world."
Dr Salisbury said he had always been puzzled by the fact that so few dinosaur fossils had been found in Australia.
"Contrary to what many people believe, we do have lots of rocks of the right age that potentially could contain dinosaurs, particularly in Queensland," he said.
"I think the main reason that not much has been found here is that not many people have been looking."
Dr Salisbury first began studying crocodilians at the University of New South Wales and went to Germany and the United Kingdom to complete a doctorate on aspects of their evolution.
"With the experience I'd gained in Europe doing my PhD, I wanted to come back here and see what I could find," he said.
"Queensland was the obvious place to start, given its huge expanses of the right type of rocks."
Recent discoveries in this state back up Dr Salisbury's hunch - sauropods, the largest dinosaurs to be found in Australia, "killer" kangaroos and large carnivorous birds all have been identified recently.
Meanwhile, Dr Salisbury believes that today's crocodiles are descended from animals that went north and came back.
"In Australia, everyone loves crocodiles," he said. "So to discover they originated here, everyone's gonna be pretty chuffed."
www.uq.edu.au/dinosaurs Last reviewed 16 October 2006