Footprints of the tree major groups of dinosaurs – sauropods, ornithopods and theropods – have been found together at a site in central Queensland. Although the prints, known as a trackway, have survived almost 100 million years, their recent exposure to the weather put them in danger, and a race against time has seen the most vulnerable removed to safety. They are set to go on display next year.
Australia, once considered a backwater for dinosaur relics, is home to some outstanding footprints. Two years ago the largest footprint ever discovered was identified in Western Australia, as astonishing 1.7 meters (5.5 feet).
In Queensland, footprints from many small dinosaurs apparently moving quite fast, and those of a much larger carnivore, have been dubbed the dinosaur stampede. Analysis has sparked major debates about dinosaur behavior, including whether some of the smaller dinosaurs were wading when they made them.
The new discovery was made 100 kilometers (60 miles) north of the stampede site, which in the vast distances of western Queensland makes them near neighbors.
"The small ornithopod and theropod footprints were clearly made by very similar (if not identical) trackmakers to those preserved at Dinosaur Stampede National Monument,” said Swinburne University's Dr Stephen Poropat in a statement. The similarity in species is unsurprising since both sets of prints were made around 95 million years ago.
A study of the prints is still in peer review, but ABC reports some came from a two-legged insect-eating theropod the size of a chicken running 10 kilometers per hour (6 miles per hour). A somewhat larger ornithopod, also on two legs, and a large four-legged sauropod made the rest.
The sauropod prints are a meter (3 feet) wide, run for 40 meters (130 feet) with spacing suggesting their maker was 3.3 meters (10 foot) high at the hip. They are so well preserved we can see the ripples and cracks the sauropod's weight produced in the surrounding mud, along with scratches made by its claws. Announcing the discovery, Queensland Tourism Industry Development minister Kate Jones noted the site also includes "the trampled tracks of other sauropods including at least one sub-adult."
Poropat described the prints as “The best of their kind in Australia.”
One end of the trackway was noticed several years ago in a dry creek, but a much larger section was exposed by major floods in March 2018. Although the area doesn't get much rain, the rare floods it experiences can be devastating, and it was feared the next flood would destroy much of the site. In a quest to preserve the precious prints, 500 tonnes (450 tons) of sandstone and substrate rock have been removed.