A boulder was donated to a high school 20 years ago. Only now has its secret been unearthed

For 20 years, a boulder sat at a regional high school without anyone realising its significance.

Its remarkable secret has finally been revealed after researchers discovered it contained one of the highest concentrations of dinosaur footprints ever documented in Australia.

The white clay boulder, about the size of a small table, features 66 fossilised footprints of small dinosaurs from 200 million years ago.

Anthony Romilio from the University of Queensland’s Dinosaur Lab.Credit: University of Queensland

The three-toed footprints from 47 individual dinosaurs date back to the Early Jurassic period, University of Queensland researcher Anthony Romilio said.

They belong to the Anomoepus scambus, a dinosaur that moved on two 50-centimetre-long legs, with a short neck, a chunky body and a small head with a beak.

“It was a plant-eating dinosaur that wasn’t particularly large by dinosaur standards,” Romilio said.

Anomoepus scambus had a short neck, a chunky body and a small head with a beak.Credit: University of Queensland

The discovery sat unnoticed at Biloela State High School in central Queensland after being donated from Callide Mine 20 years ago.

“Significant fossils like this can sit unnoticed for years – even in plain sight,” Romilio said.

The footprints on the boulder were likely made by the dinosaurs passing over a patch of wet, white clay while walking along or crossing a waterway.

They would not have been travelling particularly fast, about 6km/h.

The footprints were likely made by the dinosaurs passing over a patch of wet, white clay.Credit: University of Queensland

Romilio was able to work out what kind of dinosaur left the peculiar marks by matching the footprints with skeletal fossils from overseas.

He said the significant discovery would help scientists better understand which dinosaurs roamed Australia millions of years ago.

“It’s an unprecedented snapshot of dinosaur abundance, movement and behaviour from a time when no fossilised dinosaur bones have been found in Australia,” he said.

The school boulder is not the only unlikely source of dinosaur knowledge that Romilio has discovered lying around central Queensland.

He found a rock with footprints being used as a carpark entry marker at Callide Mine near Biloela.

The much larger boulder, weighing about 2 tonnes, featured two distinct footprints left by a bigger dinosaur walking on two 80-centimetre-tall legs.

“We have gained new insight into the ancient past in this region,” Romilio said.

The research is published in Historical Biology.

AAP