A large set of tracks from Pyrenees made by archosauromorphs may be evidence of a new type of footprint from reptiles existed about 247 million years ago.
The Permian mass extinction resulted in the destruction of approximately 90 percent of species. The climatic and environmental conditions hindered the vertebrae species from recovering after this event.
The researchers led by Eudald Mujal from Universitat Autònoma de Barcelona analyzed the trace fossils of vertebrates discovered in Pyrenees mountain range in Catalonia that lived about 247 to 248 million years ago. They investigated which vertebrates existed in Mesozoic Era (before Permian mass extinction), and produced 3D models of the fossils made up of silicone molds that let them preserve the fossils in scientific collections.
They noticed that a majority of the tracks were made by archosauromorphs - ancestors of crocodiles and dinosaurs. Most of the tracks were small (half a meter in length), but the few samples were longer than three meters. The new footprint of Prorotodactylus mesaxonichnus hints that Pyrenean Prorotodactylus genus is related to archosauromorphs rather than dinosauromorph.
The researchers believe that the remains of archosauromorph fossils in the Pyrenees Mountain may present evidence that archosauromorphs had a large role in vertebrate recovery after the Permian mass extinction. They may also hint at the fluvial environments of the Catalan Pyrenees throughout the Triassic vertebrate improvement following the end-Permian mass extinction.
Still, further research is required to recognize how archosauromorph lineage evolved and spread during this period, Mujal noted.