A newfound "chicken-size" dinosaur, recently unearthed in Wyoming, changes what paleontologists thought they knew about how dinosaurs spread across the globe.

Researchers discovered Ahvaytum bahndooiveche fossils in Wyoming, revealing dinosaurs in Laurasia earlier than believed.

The oldest equatorial dinosaur in the world, and North America's oldest dinosaur, has been described in a new study. Dating back 230 million years, the chicken-sized dinosaur has big implications for our understanding of how dinosaurs spread across the world,

How and when did dinosaurs first emerge and spread across the planet more than 200 million years ago? That question has for decades been a source of debate among paleontologists faced with fragmented fossil records.

Dinosaurs inhabited the Northern Hemisphere millions of years earlier than scientists previously thought, according to the new research.

For decades, paleontologists have debated how and when dinosaurs emerged and spread across the planet more than 200 million years ago. The prevailing theory suggested that dinosaurs first arose in the southern part of the ancient supercontinent Pangaea,

This discovery challenges the long-held belief that dinosaurs originated exclusively in the southern supercontinent, Gondwana.