A recent study published in PLOS ONE has unveiled new fossils of ornithomimosaurs, or “bird-mimic” dinosaurs, from the Late Cretaceous Eutaw Formation in Mississippi. These ostrich-like dinosaurs inhabited the ancient landmass of Appalachia in eastern North America, where fossils are typically scarce. Researchers identified two species from the findings, one small and one notably large, with the latter weighing over 800 kg (1,760 pounds) and still growing at the time of its death. This discovery enhances our understanding of dinosaur ecosystems during the Late Cretaceous and illuminates trends in ornithomimosaur evolution, particularly the prevalence of giant sizes and coexistence of multiple species across North America and Asia. The findings suggest that large and medium-sized ornithomimosaur taxa cohabited during this period, indicating a rich diversity in North American ecosystems. This study offers valuable insights into the rarely understood dinosaur evolution in Appalachia, providing evidence of the ecological strategies that enabled these dinosaurs to thrive. Further research may explore the reasons behind these successful life strategies. The research was led by Chinzorig Tsogtbaatar from the North Carolina Museum of Natural Sciences and co-authored by several experts.
