230-Million-Year-Old Dinosaur Fossil Redefines Early Evolution Timeline

Discovery of Ahvaytum bahndooiveche in Wyoming reveals dinosaurs existed in the northern hemisphere millions of years earlier than previously believed.

Ahvaytum bahndooiveche, the oldest known dinosaur from North America, lived approximately 230 million years ago in what is now Wyoming.
The discovery challenges the long-standing theory that dinosaurs originated in the southern hemisphere and only spread north millions of years later.
Radioisotopic dating of the Popo Agie Formation confirms the fossils' age, aligning them with the earliest known dinosaurs from the southern supercontinent Gondwana.
The chicken-sized dinosaur, likely an early sauropod relative, provides critical insight into the global distribution and evolution of early dinosaurs.
The species name, chosen in collaboration with the Shoshone Tribe, reflects a partnership with Indigenous communities to honor their ancestral lands.