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More than 66 million years ago, a “tyrant lizard king” ruled western North America: the fearsome predatory dinosaur Tyrannosaurus rex. But how large was this monarch’s royal family? Could what we call ...

The premise, put forth in a new paper, highlights an assortment of tensions in dinosaur paleontology, including how subjective the naming of species can be. By Asher Elbein Tyrannosaurus rex is the ...

Since its discovery in 1902, there’s only been one known type of Tyrannosaurus: the rex. However, a new study says there were three types of Tyrannosaurus, based on differences in fossils' femurs and ...