Across South Africa, paleontologists have encountered various mysterious bird-like footprints resembling the tracks of modern-day birds. The tracks date to the Late Triassic and Early Jurassic periods in a new study for PLoS ONE.
During this time, birds and dinosaurs co-existed, and both prints are commonly found preserved on the same surfaces. Researchers are still determining what ancient animal made these tracks. But, the find places bird-like feet with three-toed footprints at 60 million years older than the world's oldest known bird, Protravis texensis.
The prints have sparked debates among paleontologists about the bird-like footprints' species. Over the years, experts have suspected Trisauropodicus, an ichnotaxon that resembles birds' tracks, Anomoepus, an ornithischian dinosaur, and even Gruipeda, as the culprits leaving behind the three-toed tracks.
How Were the Tracks Analyzed?
To pinpoint what could have made the footprints, the team reexamined the original cast material from the Université de Montpellier in France, photographs of 164 fossilized prints, and compared sketches. Experts also sifted through published materials that described four sites in Lesotho in Southern Africa.
Researchers observed the tracks and split them into two categories, one that did not resemble bird tracks and the other that was more avian-like, with slender digits without any distinct pads, wide toe angles, and similar in size, according to a press release.
Read More: What Makes Archaeopteryx Fossils the Bizarre Bridge Between Dinos and Birds?
A Mysterious Bird-Legged Creature
The tracks did not directly match any known fossilized animals from the region or period. In fact, the prints were even older than the earliest known bird bones by 60 million years at 210 million years old.
Researchers suspect the prints were made by early dinosaurs and perhaps an early bird-like or near-bird ancestor. However, the team quickly notes that other reptile species could have been running around at the time that also evolved the bird-like feet independently along with their cousins, the dinosaurs.
The authors write that identifying what species the bird-like tracks belong to is challenging, and they still need to figure out what exactly made the prints. The age of the fossils, however, points to them being some type of dinosaur, which goes back to as early as the late Triassic Period.
Read More: One of the Earliest Birds Ever Discovered Has Rare, Stork-Like Legs
