While space and physics discoveries tend to dominate science headlines, new paleontological discoveries are still being made every day. Just this week, Chinese construction workers stumbled across a completely new dinosaur species while blasting with dynamite. While new dinosaur discoveries are certainly interesting, they still usually fit within existing dinosaur knowledge. However, a new set of fossils uncovered in Brazil has the potential revise much of our current knowledge about the evolution of dinosaurs and rewrite early dinosaur history.
The fossils were found in Brazil’s Carnian Santa Maria Formation, a 230-million-year-old rock bed containing scores of dinosaur fossils. The fossils comprised two completely new species – the dinosaur species Buriolestes schultzi, and the lagerpetid species Ixalerpeton polesinensis. Lagerpetids were a class of dinosaur precursor species generally thought to have gone extinct by the time dinosaurs evolved. However, the paleontologists behind this discovery claim that the presence of these new lagerpetid and dinosaur species side by side indicates that perhaps dinosaur evolution wasn’t as abrupt as previously thought.
According to their research published in Current Biology, the researchers claim this discovery challenges past fossil evidence which indicated these two classes of dinosauromorphs (dinosaurs and dinosaur-like creatures) only co-existed briefly and only in isolated habitats:
Based on much more complete remains, the new discovery confirms that the co-occurrence between non-dinosaurian Dinosauromorpha and dinosaurs was not restricted to later stages of the Triassic and to the northern parts of Pangaea where silesaurids and lagerpetids have been found together with theropod dinosaurs, reinforcing rapid replacement as a very unlikely scenario for the initial radiation of dinosaurs.
The fact that these two animals coexisted shows that dinosaur evolution might have been more gradual and complicated than paleontologists have previously speculated. Many of the physiological features on the newly discovered dinosaur indicate that Buriolestes schultzi was carnivorous early in its evolution and later evolved to feed entirely on plants. That find alone poses certain questions about why and when this group of dinosaurs switched to a plant-based diet, which could indicate previously unknown environmental changes.