2.5 billion T. rex inhabited the planet, researchers say
The number is staggering: 2.5 billion Tyrannosaurus rex lived and died during the roughly 2.4 million years the species survived on the planet, according to a new study set to be published in the journal Science on Friday. The study may help contextualize the fossil record and the rarity of finding certain fossilized prehistoric organisms, according to lead researcher Charles Marshall, director of the University of California Museum of Paleontology.