Apex predators, like the Tyrannosaurus rex, eventually arose from smaller-bodied tyrannosauroid dinosaurs called Khankhuuluu ...

Since the closest-known relatives of Tyrannosaurus are from Mongolia, Dr. Holtz said, some researchers argued that Tyrannosaurus represented a specific group that crossed a land bridge from Asia.

A rendering shows Tyrannosaurus mcraeensis, a newly discovered relative of Tyrannosaurus rex. The creature likely roamed Earth up to 7 million years before T. rex. Sergey Krasovkiy/Courtesy of New ...

Tyrannosaurus rex is likely the most famous dinosaur known to man. Not only was this mega-beast the largest predator in its ecosystem, it also had teeth as long as your forearm and a bite force to ...