The total Tyrannosaurus rex population that existed during the estimated 2.4 million years that this fearsome species inhabited western North America during the twilight of the age of dinosaurs. It was among the largest carnivorous dinosaurs, possessing a skull about 5 feet long, massive and muscular jaws with a bite force capable of crushing bone, serrated teeth, a keen sense of smell, strong legs and puny arms with hands boasting just two fingers. Researchers calculated an average population density of about one T. rex for every roughly 100 sq. kms. Perhaps the largest-known T. rex is a specimen named Sue at the Field Museum in Chicago, measuring 40 and a half feet in length and weighing an estimated 9 tons that lived about 33 years.
Once we figured out the average population size, we were able to calculate the fossilization rate for T. rex – the chance that a single skeleton would survive to be discovered by humans 66 million years later. The answer: about 1 in 80 million. That is, for every 80 million adult T. rex, there is only one clearly identifiable specimen in a museum.
This number highlights how incomplete the fossil record is and allows researchers to ask how rare a species could be without disappearing entirely from the fossil record.
Beyond calculating the T. rex fossilization rate, our new method could be used to calculate population size for other extinct species.
Picture Credit : Google
