Tyrannosaurus Rex lived during the late Cretaceous period; this was approximantely 67 to 66.5 million. The species lived during the final age of dinosaurs on Earth until a catastrophic extinction event eventually eradicated all dinosaur species.
Before a meteor struck Earth and caused the great extinction event, Tyrannosaurus Rex was a fierce predator living on a planet full of many types of dinosaurs. Tyrannosaurus Rex primarily lived in what is now North America, and numerous skeletons, teeth and bones have been found by palaeontologists in various regions of the United States. As of 2014, experts are unsure of exactly how long the average life span of a Tyrannosaurus Rex was, but some believe they died about six years after sexual maturity. A skeleton unearthed in South Dakota is thought to be from a female that lived 28 years.