An undated handout photo released by the University of Queensland shows an image of the boulder using 3D imaging and light filters showing the dinosaur footprints. Credit: University of QueenslandShareA large boulder used as decoration in a rural Australian high schools foyer is actually covered in dinosaur footprintsit just took around 20 years for anyone to notice. After examining the ancient rock, paleontologists at the University of Queenslands Dinosaur Lab believe the stone features one of the countrys highest concentrations of fossilized footprints. These tiny tracks were created by dozens of small, two-legged herbivores during the early Jurassic period. The team describes their findings in a study published on March 10 in the journal Historical Biology.Eastern Australias Biloela State High School is located near the Callide Coal Mine. Workers at this largescale operation often blow up rock formations to reach their payloads. Around 20 years ago, a geologist working at the site took note of a rock formation dotted with what looked like chicken footprintsalbeit chickens with three instead of the standard four or five toes. The geologist extracted the rock before the area was slated for mining, and donated it to Bioela State High School where his wife taught.For years, the boulder greeted students and faculty as a symbol of the areas geologic history. However, following local media attention on newly discovered dinosaur fossils in the area in 2021, the school decided to ask for an experts closer inspection of the rock from the coal mine. University of Queensland paleontologist Anthony Romilio paid a visit to Biloela State High School, where he quickly realized the slabs significance.In the new study, Romilio and colleagues documented a total of 66 fossilized footprints from 47 separate dinosaurs, all within a roughly three-square-foot section of the rock.Its a huge number of dinosaurs, and its the highest number found in a single slab in Australia, Romilio told NBC News. Get the Popular Science newsletter Breakthroughs, discoveries, and DIY tips sent every weekday. By signing up you agree to our Terms of Service and Privacy Policy.After analyzing casts made of the footprints, the team determined they belonged to Anomoepus scambus, a plant-eating dinosaur that existed during the early Jurassic period about 200 million years ago. A. scambus was a comparatively small animal, with a leg height ranging from around 10 centimeters to just over one foot.Speaking with the Australian Broadcasting Corporation, Romilio explained discoveries like the one at Bioela State High School serve as a reminder of how important it is for mining operations to proceed carefully in their work.When you have an industry like open-pit mining the general assumption is that you wont be able to extract and preserve dinosaur footprints because the process [to mine] is quite destructive, he said on March 11. Thats another idea thats been shattered because we can get these amazing fossils.