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| | Earth on Jan 20, 2013

World’s only recorded dinosaur stampede … maybe not

New research published in January 2013 in the Journal of Vertebrate Paleontology suggests the dinosaurs were swimming, not stampeding.

Tracks left by dinosaurs nearly 100 million years ago at Dinosaur Stampede National Monument in Queensland, Australia.

The world’s only recorded dinosaur stampede wasn’t a stampede, after all, according to Queensland, Australia paleontologists. University of Queensland PhD candidate Anthony Romilio led the study suggesting that the tracks – memorialized at the Dinosaur Stampede National Monument at Lark Quarry Conservation Park in central Queensland, Australia – actually were made by swimming, not running, dinosaurs. Romilio told the Sydney Morning Herald on January 10, 2013:

Many of the tracks are nothing more than elongated grooves, and probably formed when the claws of swimming dinosaurs scratched the river bottom.

The dinosaurs were swimming, says PhD candidate Anthony Romilio, whose work was published in the January 2013 issue of the Journal of Vertegrate Paleontology. He believes the dinos were likely small, two-legged herbivorous dinosaurs known as ornithopods. Image via Anthony Romilio.

Anthony Romilio of the University of Queensland. Photo by Steve Salisbury via University of Queensland website.

Some 4,000 dinosaur tracks – thought to be 95 million to 98 million years old – are preserved in beds of siltstone and sandstone at Lark Quarry. They were first discovered in the 1960s. It was thought that a shallow river once flowed here, when this area was part of a vast, forested floodplain. And it was believed that a group of perhaps 180 small dinosaurs – of two different species – were disturbed when a much-larger carnivorous dinosaur arrived. The small dinosaurs were thought to have stampeded, leaving thousands of footprints in the surrounding mudflat.

See a photo gallery from the Dinosaur Stampede National Monument here.

Anthony Romilio, who led an analysis of the sediments in this area, expanded on this story in several ways. He found evidence for a seasonal flow of the river – with water flowing at different depths and speeds at different times. He said the tracks were made by just one dinosaur species – small, two-legged herbivorous dinosaurs known as ornithopods. He said the footprints were probably made over a period of several days, by dinosaurs crossing the water. And he said the dinosaurs were swimming to cross the river, not stampeding.

Romilio published his research in the January 2013 issue of the Journal of Vertebrate Paleontology.

The first video below offers a beautiful reconstruction of the original thinking behind the “dinosaur stampede” at Dinosaur Stampede National Monument in Australia. It’s part of the TV series The Time Traveler’s Guide from Australia’s ABC Television.

The second video below shows what we’re left with, if the world’s only recorded dinosaur stampede wasn’t one. This second video – wholly imaginary – is from the 2005 remake of the movie King Kong. It’s a good one, and I like it … as long as Adrien Brody doesn’t get squashed.

Bottom line: University of Queensland paleontologists say that the fossil record of what was thought to be the world’s only recorded dinosaurs stampede actually was left by swimming, not running, dinosaurs. The 4,000 dinosaurs tracks may be found at Dinosaur Stampede National Monument at Lark Quarry Conservation Park in central Queensland, Australia.