WASHINGTON (REUTERS) - If one tyrannosaurus rex - the school bus-sized meat-eating dinosaur that stalked the Cretaceous period landscape - seems impressive, how about 2.5 billion of them?
Researchers on Thursday (April 16) unveiled the first calculation of the total T-rex population during the estimated 2.4 million years that this fearsome species inhabited western North America during the twilight of the age of dinosaurs.
They considered factors, including the size of its geographic range, its body mass, growth pattern, age at sexual maturity, life expectancy, duration of a single generation and the total time that T-rex existed before extinction 66 million years ago.
They also heeded a doctrine called Damuth s law linking population to body mass: the bigger the animal, the fewer the individuals.
According to experts, 2.5 billion Tyrannosaurus rex dinosaurs roamed North America during the late Cretaceous period.
The researchers estimate that about 20,000 adult T. rexes were alive at any given time during the species lifetime - give or take a factor of ten.
(Photo: Getty Images) NEW YORK, NEW YORK - SEPTEMBER 17: A Tyrannosaurus Rex dinosaur fossil skeleton is displayed in a gallery at Christie’s auction house on September 17, 2020, in New York City. Owned by the Black Hills Institute of Geological Research in South Dakota, the skeleton is known as “Stan” for the amateur paleontologist Stan Sacrison who found the initial bones in 1987. The bones were discovered in a remote area that spans North and South Dakota, Wyoming, and Montana. Stan, with an estimated value between $6 million and $8 million, is considered one of the largest and most complete examples of a T-Rex, with 188 original bones. The skeleton will be auctioned as part of Christie’s 20th Century evenin
Researchers say a staggering 2.5 billion T. rex once roamed the Earth
“That’s a lot of jaws. That’s a lot of teeth. That’s a lot of claws,” said the study’s lead author Charles Marshall. By
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Researchers at the University of California, Berkeley calculated that over the course of 127,000 generations, around 2.5 billion T. rex lived on the planet.
The T. rex population were not all confined to the same place, the research shows.
Around 3,000 T. rex would occupy an area the size of California.
Researchers at the University of California, Berkeley calculated that over the course of 127,000 generations, around 2.5 billion T. rex lived on the planet. The group, which published its finding Thursday in Science, arrived at this number by calculating the dinosaurs’ approximate body size, sexual maturity and estimated energy consumption.