A 230-million-year-old dinosaur fossil found in Wyoming is the oldest known dinosaur to be discovered in North America, challenging scientists’ previous understanding of how dinosaurs spread across the globe.
The newly unearthed raptor, Ahvaytum bahndooiveche, was approximately one foot tall and three feet long. It was likely a distant ancestor of massive sauropod dinosaurs that emerged 50 million years later. The discovery has rewritten what paleontologists thought they knew about how quickly dinosaurs conquered the planet.
The fossil record suggested that it took up to 10 million years for dinosaurs to spread from the southern half of Pangea to the northern half, but this new find is only around three million years younger than the oldest commonly agreed upon Gondawanan dinosaur. The exact timing of dinosaurs’ emergence in Laurasia remains a mystery, with researchers proposing that unusually wet climatic conditions may have played a role.
The discovery has left scientists re-evaluating their understanding of dinosaur history and evolution. It is believed to be a significant piece of evidence that shows dinosaurs were present in the Northern Hemisphere much earlier than previously thought.
Source: https://www.livescience.com/animals/dinosaurs/230-million-year-old-dinosaur-is-oldest-ever-discovered-in-north-america-and-changes-what-we-know-about-how-they-conquered-earth