Washington: A researcher from the University of Alberta has discovered the most compelling evidence yet that two-legged dinosaurs could swim for long distances.
Working together with an international research team, U of A graduate student Scott Persons examined unusual claw marks left on a river bottom in China that is known to have been a major travel-way for dinosaurs.
Alongside easily identified fossilized footprints of many Cretaceous era animals including giant long neck dinosaur`s researchers found a series of claw marks that Persons says indicates a coordinated, left-right, left-right progression.
"What we have are scratches left by the tips of a two-legged dinosaur`s feet," said Persons. "The dinosaur`s claw marks show it was swimming along in this river and just its tippy toes were touching bottom."
The claw marks cover a distance of 15 meters which the researchers say is evidence of a dinosaur`s ability to swim with coordinated leg movements. The tracks were made by carnivorous theropod dinosaur that is estimated to have stood roughly 1 meter at the hip.
Fossilized rippling and evidence of mud cracks indicate that over 100 million years ago the river, in what is now China`s Szechuan Province, went through dry and wet cycles. The river bed, which Persons describes as a "dinosaur super-highway" has yielded plenty of full foot prints of other theropods and gigantic four-legged sauropods.
With just claw scratches on the river bottom to go with, Persons says the exact identity of the paddling dinosaur can`t be determined, but he suspects it could have been an early tyrannosaur or a Sinocalliopteryx. Both species of predators were known to have been in that area of China.