Australia: The Land Where Time Began

A biography of the Australian continent 

Burrowing Dinosaur

In the Otway Group, of Albian age of Victoria, structures have been found that are believed to be burrows dug by burrowing dinosaurs. This would be the first known evidence of burrowing dinosaurs outside North America. They would also be the earliest known burrowing dinosaurs in the world. Very similar structures from the Upper Cretaceous (Cenomanian) of Montana in the US have been attributed to Oryctodromeus cubicularis. The suspected burrows overlie strata containing dinosaur tracks. The burrow is a 2.1 m long, gently sloping semi-helical tunnel with an almost constant diameter of about 30 cm that connects with an enlarged chamber. The estimated size of the occupant of the burrow, about 10-20 kg, matches the estimated size of small ornithopods known from the Otway Group. It had previously been proposed that hypsilophodontid dinosaurs in Australia, a type comprising most of the dinosaur assemblages known from Lower Cretaceous Victoria, had adopted the burrowing behaviour as a means of surviving the polar conditions that existed in southeastern Australia at that time.

Dinosaur burrows in the Otway Group (Albian) of Victoria, Australia, and their relation to Cretaceous polar environments