For more than 20 years, a slab of rock covered with dinosaur footprints has been on display at Biloela High School in Queensland, Australia. A local geologist donated the fossil-covered rock to the school in 2002. Recently, scientists discovered that the slab contains one of the highest concentrations of dinosaur footprints ever found on the continent.
Anthony Romilio, a paleontologist from the University of Queensland, identified 66 footprints on the rock’s surface. The impressions were likely made by 47 small two-legged dinosaurs that Romilio says “walked together at a relaxed pace” over wet, soft clay about 200 million years ago.
Footprints are trace fossils—preserved records of an organism’s behavior that can also include bite marks, burrows, and poop. These are especially valuable when studying ancient animals that haven’t left behind any known body fossils, like bones or teeth. “It was incredible to find such a valuable glimpse into Australia’s distant past sitting quietly in a school foyer,” says Romilio.