Tyrannosaurus

The tyrant lizard king — the most studied predator of the Mesozoic.

Tyrannosaurus is a genus of large theropod dinosaur that lived at the very end of the Cretaceous Period, roughly 68 to 66 million years ago. Its single widely recognized species, Tyrannosaurus rex, is among the best-documented dinosaurs ever found, known from dozens of partial skeletons unearthed across western North America. It was one of the last large dinosaurs to exist before the end-Cretaceous extinction.

Built to bite

With a skull over 1.5 metres long and thick, banana-shaped teeth, T. rex had one of the most powerful bites of any known land animal — strong enough to crush bone. Its body was balanced over two muscular legs, with a heavy tail as a counterweight and famously small two-fingered arms whose function is still debated.

How we know

The genus was named by Henry Fairfield Osborn in 1905, based on a partial skull and skeleton collected by Barnum Brown in Montana's Hell Creek Formation a few years earlier. Since then, specimens such as 'Sue' and 'Stan' have made T. rex one of the most complete and intensively researched dinosaurs, informing estimates of its growth, posture, and biology.

Where it lived

Tyrannosaurus fossils come from the Hell Creek, Lance, and related formations of the western United States and Canada — floodplains and forests at the close of the Cretaceous. It shared this world with horned dinosaurs like Triceratops, which appear in the same rock layers.

Sources

Compiled by PaleoDex from open scientific data. Like the app, every fact here is sourced — primarily the Paleobiology Database and Wikipedia/Wikimedia — and where a fact isn't sourced, we leave it out rather than guess.

· Wikipedia: Tyrannosaurus
· Paleobiology Database (PBDB)