A diet of beetles and burnt plants
In a clay pit near the village of Krasiejów, Poland, paleontologists unearthed evidence detailing life during the Late Triassic, around 230 million years ago. This evidence was bones and hundreds of coprolites (fossilized feces) and bromalites (fossil vomit). These trace fossils provide a direct record of the diets and interactions within an ancient ecosystem on the supercontinent Pangaea. The site has yielded remains of various animals, including a large predatory rauisuchian called Polonosuchus silesiacus and early dinosauromorphs—the ancestors of dinosaurs.
An important animal in this environment was Silesaurus opolensis, a dinosauromorph about 2.3 meters long. Traditionally considered an herbivore based on its teeth, analysis of its likely coprolites revealed a more complex diet. Researchers took the fossilized feces to the European Synchrotron Radiation Facility (ESRF) in France. There, they used a technique called propagation phase-contrast synchrotron microtomography, hitting the coprolites with high-energy X-rays to create detailed 3D models of their contents without destroying them. The scans revealed numerous beetle remains, including delicate wing cases (elytra) and leg parts, suggesting Silesaurus opolensis was omnivorous, deliberately targeting insects. This pecking behavior is analogous to some modern birds.