Dinosaurs were swimming not running during stampede
Melbourne: Paleontologists in Queensland have found that the world's only recorded dinosaur stampede is largely made up of the tracks of swimming, not running, animals.
The University of Queensland's PhD candidate Anthony Romilio led the study of thousands of small dinosaur tracks at Lark Quarry Conservation Park in Queensland's central west.
The tracks, which are 95 to 98 million years old, are preserved in beds of siltstone and sandstone deposited in a shallow river when the area was part of a vast, forested floodplain, News.com.au reported.
He said that many of the tracks are nothing more than elongated grooves, and probably formed when the claws of swimming dinosaurs scratched the river bottom.
Some of the more unusual tracks include "tippy-toe" traces - this is where fully buoyed dinosaurs made deep, near vertical scratch marks with their toes as they propelled themselves through the water, he said.
He added that it's difficult to see how tracks such as these could have been made by running or walking animals.
Romilio said the swimming dinosaur tracks at Lark Quarry belonged to small, two-legged herbivorous dinosaurs known as ornithopods.
"These were not large dinosaurs. Some of the smaller ones were no larger than chickens, while some of the wading animals were as big as emus," he said.
The findings are published in the Journal of Vertebrate Paleontology.