Students at a Queensland high school got a thrilling palaeontology lesson this week when a researcher confirmed that a rock slab stored on their campus for two decades preserves dozens of dinosaur footprints dating back some 200 million years.
The fossil originates from the Callide Basin in the northeastern state of Queensland. Coal miners unearthed it in 2002, and after spotting unusual footprints embedded in it, they notified a local geologist, who gifted the rock to Biloela State High School, where his wife taught science. The rock became a central sight in the student foyer to the main office, elevated on a stand and surrounded by colourful dinosaur murals painted by pupils.
Still, school officials didn’t grasp the full significance of the fossil — some even mistook it for a replica — until palaeontologists verified the markings belonged to small, two-legged dinosaurs from the early Jurassic era. They published their findings Monday in the peer-reviewed journal Historical Biology.
This is “one of the highest concentrations of dinosaur footprints” ever documented in Australia, University of Queensland paleontologist Anthony Romilio, the study’s lead author, said in a statement. “It’s an unprecedented snapshot of dinosaur abundance, movement and behavior from a time when no fossilized dinosaur bones have been found in Australia.”
The oldest dinosaur bones in Australia come from the Middle Jurassic period around 160 million years ago, Romilio clarified over email. “Footprint fossils, like these ones, are the only evidence Australia has of dinosaurs before this period,” he said.
The school is located in the rural town of Biloela about 9 miles south of the Callide Basin. Though dinosaur footprints have been reported in the area for more than three decades, only one track had been formally described before now. The newly analyzed fossil contains a single three-toed print on one surface and a trackway with two tracks on another. A third surface features at least 13 trackways and many isolated prints. The researchers identified 66 fossilized prints in total, estimated to have been left by 47 creatures.
“We obviously always considered the fossil to be historically significant in terms of the age and being related to dinosaurs and their history in central Queensland,” David Hall, the school’s deputy principal, said in an email. “We were not aware of the significance of the quantity of the footprints in the specimen being so unique.”
The study out this week details how Romilio and other researchers identified the prints as belonging to ornithischian dinosaurs, herbivores with a pelvic structure similar to that of birds. The small dinosaurs that left their imprints on the schoolhouse rock had legs ranging in length from 15 to 20 inches and were moving at less than 4 miles per hour across watery terrain when they left their mark, Romilio estimates.
The prints that preserve their journey measure between 2 inches and nearly 8 inches long, though most add up to around 4 to 4.7 inches. The schoolhouse rock measures less than a square meter in area, but it’s heavy enough that it took two of Romilio’s former students to lift it from its stand and place it flat on the ground so the scientist could make a silicone mold of the prints for further study.
Romilio then examined the fossil by taking photos of the surface and converting them to a virtual 3D model. Many of the footprints aren’t visible to the naked eye, but digital models allow researchers to adjust lighting and apply depth resolution filters to reveal hidden details.
“It was only after doing that back in the lab that the myriad footprints popped out,” Romilio said.
Fossils Where You Least Expect Them
Sometimes, the most exciting fossil discoveries hide in plain sight. In December, New York homeowners spotted what turned out to be a complete mastodon jaw protruding from the soil in their yard.
“The vast majority of dinosaur fossils, they’re not found by paleontologists,” Romilio said. “They’re actually found by people on the ground.”
Members of the local community contacted Romilio about the high school fossil after learning of his work on other footprints discovered nearby. The study in Historical Biology also describes dinosaur footprints he observed on a 2-ton boulder at the coal mine parking lot.
“It’s incredible to think that a piece of history this rich was resting in a schoolyard all this time,” he said. “Its true significance is difficult to assess until someone has done the research, and now we are all celebrating it.”
This post was originally published on forbes.com.
Look back on the week that was with hand-picked articles from Australia and around the world. Sign up to the Forbes Australia newsletter here or become a member here.
