A recent discovery in Wyoming has shaken our understanding of global dinosaur history, revealing that dinosaurs were not confined to the Southern Hemisphere for millions of years before spreading into other regions. Fossil fragments of a tiny creature, named Ahvaytum bahndooiveche, have been dated to around 230 million years old and are now considered the oldest-known dinosaur from Laurasia, the Northern Hemisphere land mass.
The discovery was made by lead author Dave Lovelace and his team, who used radioisotopic analysis of the fossil specimens. The tiny ‘terrible lizard’ is estimated to be around the size of a chicken with a long tail. It’s now believed that dinosaurs didn’t start out as giant behemoths but rather evolved over time.
The discovery places Ahvaytum bahndooiveche in a similar time period to dinosaurs from Gondwana, the Southern Hemisphere land mass. The researchers found nearly 6-10 million years of separation between these faunas and the oldest known dinosaur occurrence in Laurasia. This suggests that dinosaurs were not confined to one region for millions of years before spreading into other areas.
The team’s research was published in the Zoological Journal of the Linnean Society. It highlights a significant shift in our understanding of dinosaur origins, which has been biased by an apparent absence of Carnian-aged Laurasian terrestrial strata. The discovery also sheds new light on the distribution of dinosaurs during this time period, suggesting that they were more cosmopolitan than previously thought.
The research involved collaboration with members of the Eastern Shoshone Tribe, who played a crucial role in conducting field work and choosing the species’ name. This collaborative effort breaks down traditional barriers in the research process and creates an opportunity for reciprocity between researchers and Indigenous communities.
Source: https://www.sciencealert.com/fossil-discovery-rewrites-global-dinosaur-history