Fossilized dinosaur footprints from the Early Jurassic period unearthed on a two-decade-old rock at an Australian educational institution.
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A breathtaking Early Jurassic record has been hidden in plain sight for two decades, on a stone slab exhibited at a high school in Biloela, Australia - according to a recent study.
Though experts were well aware that the 1.5-meter-long (approx. 5-foot-long) slab dated back some 200 million years and bore numerous visible dinosaur footprints, its true significance remained elusive.
Now, a squad of paleontologists scrutinizing the rock's surface discovered 66 fossilized footprints from 47 individual dinosaurs belonging to the ichnospecies Anomoepus scambu. Ichnospecies refer to organisms identified solely through fossilized traces they leave, such as footprints.
This discovery offers one of the highest concentrations of dinosaur footprints per square meter ever documented in the country, offering an "unprecedented glimpse" into the abundance of dinosaurs during the Early Jurassic. Unfortunately, during this period, no dinosaur bones have been found in Australia - making these footprints its only direct evidence of the dinosaurs that roamed the land during earlier times.
Fossil dinosaur footprints aren't known to garner much attention among researchers - even paleontologists - as this finding illustrates. In Australia, where the oldest fossilized dinosaur bones originate from the Middle Jurassic - around 160 million years ago - "footprint fossils are the only proof our country has of the types of dinosaurs we had at earlier times," explained lead study author Dr. Anthony Romilio, a paleontologist and research associate at The University of Queensland's Dinosaur Lab.
The stone slab provides an unusual opportunity to observe the behavior and activity of a dinosaur that has only been recognized by its footprints in various regions across the globe.
Through innovative 3D imaging and light filters, Dr. Romilio was able to uncover concealed details buried in the stone slab, revealing the multitude of footprints and other features such as the direction in which the creatures that left the prints were traveling.
The 66 fossilized footprints, measuring anywhere from 5 to 20 centimeters (roughly 2 to 8 inches) in length, indicate that the dinosaurs may have been crossing a waterway or moving the length of one - as there are no ripples on the stone surface to provide a sense of the river flow's direction.
Based on his analysis, Dr. Romilio identified 13 sequences of footprints, made by 13 dinosaurs, as well as 34 isolated footprints, totaling 47 individuals. The dinosaurs responsible for the tracks would have had legs roughly 15 to 50 centimeters (around 6 to 20 inches) long, with a sturdy body and short arms.
"Though trace fossils are often dismissed because they are more abundant than dinosaur bones, they can provide an astonishing wealth of information when properly analyzed," said Dr. Paul Olsen, a paleontologist and Arthur D. Storke Memorial Professor of Earth & Environmental Sciences at Columbia University.
Footprints "offer insight into animals that were present, even when we don't have their bones... They're a parallel dataset that helps us trace, pun intended, what's happening when the bones are scarce. That's why they're so crucial," explained Olsen, who has studied Anomoepus but was not part of this research.
Based on what is known from other found tracks worldwide, A. scambus was a three-toed, two-legged dinosaur that belonged to the ornithischian family - a group that includes other plant-eating dinosaurs like duckbills and triceratops. This new discovery, preserving much anatomical detail, supports the notion that "small ornithischian dinosaurs attained a global distribution by the Jurassic Period's beginning."
The study authors also analyzed two other instances of trace fossils in unlikely locations. They found that a 2,000-kilogram (approx. 4,400-pound) boulder used as a parking lot entry marker at the Callide Mine near Biloela contained two distinct footprints left by a slightly larger dinosaur. Additionally, a third rock used as a bookend had a single footprint.
The stone slab kept at the high school was also originally from the Callide Mine, an open-cut mine where the overlying rock is extracted to access coal beneath. This excavation effort can uncover fossil footprints like these across many miles, dating back to the Early Jurassic period.
"Certainly, there are more fossils out there. Whether they will be discovered in time or if it's safe to pick them up remains to be seen. We're simply fortunate that these, along with a few others, have been discovered, recovered, and available for researchers like me to study and share the findings," concluded Dr. Romilio.
- The lucky discovery of numerous dinosaur footprints on a stone slab in Biloela, Australia, has added significant value to the slab, as it now serves as a remarkable marker of one of the highest concentrations of dinosaur footprints per square meter ever documented, offering an unprecedented glimpse into the abundance of dinosaurs during the Early Jurassic.
- Fossil dinosaur footprints, such as those found in the stone slab, may not typically garner much attention among researchers, but their significance lies in the wealth of information they can provide when properly analyzed. Footprint fossils, like the multitude on the slab, offer insight into dinosaurs that may be otherwise unknown due to the scarcity of dinosaur bones.
- The footprints on the stone slab provide an exceptional opportunity to observe the behavior and activity of a dinosaur that has only been recognized by its footprints in various regions across the globe, offering a unique parallel dataset that helps researchers trace what was happening during the Early Jurassic period when dinosaur bones are scarce.
