Dinosaurs are the extinct relatives of birds that roamed the lands and seas of ancient Earth. They first appeared around 240 million to 230 million years ago in the Triassic Period, and went extinct ...

When it comes to dinosaur extinction, the working idea is what’s called the bolide impact. This is the hypothesis that a meteorite came to the surface of the Earth, hit the Earth and led to the ...

Where they lived: Dinosaur fossils have been found on every continent, including Antarctica. What they ate: Some ate plants, while others ate animals, including other dinosaurs. How big they were: The ...

Rocks formed immediately before and after non-avian dinosaurs went extinct are strikingly different, and now, tens of millions of years later, scientists think they’ve identified the culprit—and it ...