This observation – that animal lineages evolve toward larger body sizes – is known as Cope's rule. It’s most prominently seen ...

Sixty-six million years ago, a massive asteroid smashed into Earth. Life has undergone at least five mass extinctions in the ...

Among the strangest branches of the dinosaur family tree are the alvarezsauroids, small, bird‑like theropods that lived from the Jurassic into the Cretaceous. They don’t fit the image of sharp‑toothed ...

A nearly complete dinosaur skeleton discovered in Patagonia is helping scientists crack the mystery of alvarezsaurs, a bizarre group of bird-like dinosaurs. The fossil of Alnashetri cerropoliciensis ...