The meat-eating dinosaurs known as theropods that roamed the ancient Earth ranged in size from the bus-sized T. rex to the smaller, dog-sized Velociraptor. Scientists puzzling over how such wildly ...

Dinosaurs were not only the largest animals to roam the Earth - they also had a greater number of larger species compared to all other back-boned animals - scientists suggest in a new paper published ...

An curved arrow pointing right. Most of us imagine dinosaurs as the huge, towering prehistoric beings that once walked the Earth. But it turns out that dinosaurs were actually a wide range of sizes — ...

A species of dinosaur recently discovered in Argentina had an armored back, distinctive jaw and tiny arms — and was roughly the size of a dog. Fossils dated to the humid Late Cretaceous period — ...

WASHINGTON -- Imagine a vicious velociraptor like those in "Jurassic Park," but only as big as a modern chicken. That's what Canadian researchers say they have found, the smallest meat-eating dinosaur ...

A tiny dinosaur the size of a wallaby has been unearthed Down Under. The newly discovered species, named Galleonosaurus dorisae, roamed a "lost world" between Australia and Antarctica 125 million ...