The newly described mosasaur Tylosaurus rex spanned up to 43 feet (13 meters) long and may have been one of the fiercest marine predators of the dinosaur age.
Two dinosaurs fossilized in combat, originally thought to involve a juvenile Tyrannosaurus rex testing its mettle against a Triceratops, actually feature a separate species frequently confused with ...
Scientists have long puzzled over the origins of a mysterious dinosaur excavated in the 1940s: Was it a young T. rex or another type of dinosaur? At first, researchers had only a tyrannosaur skull to ...