Tyrannosaurus rex it is perhaps the most iconic of all dinosaurs, immortalized in film, children’s toys and stupid Halloween costumes. His name translates as “king of tyrannical lizards,” and his frightening profile clearly shows why: T. Rex had a massive head, strong jaws, razor-sharp teeth, and a whip-like tail. (Although his tender arms are a comic contrast to the rest of his face.) T. Rex is believed to have been one of the largest terrestrial carnivores of all time, with a length of more than 40 feet and a height of 12 feet at hips.
But, like many extinct animals, it is difficult to know how much threat T. Rex had during his reign. (In particular, it has been debated for years whether T. Rex was a predator or shaker, although recently the scientific consensus has leaned toward the predator.) They were as common as rabbits or very scattered predators, such as snow leopards. ?
A group of scientists led by Charles R. Marshall, director of the University of California’s Paleontology Museum, set out to answer just that. They think they can now appreciate about how many T. Rexes have roamed the planet.
Their estimate is about 2.5 billion specimens that roamed the Earth collectively during their existence, which lasted several million years. (Probably several generations would have lived if not for the extinction event probably caused by a meteorite or comet 66 million years ago.)
The researchers, who published their findings in the journal Science, estimate that the abundance of T. rexes at one time was about 20,000 individuals and that they lived for about 127,000 generations. To put this in context with today’s predatory populations, that number of 20,000 is comparable to today’s African lion population, which conservatives estimate at 25,000.
Scientists have come to their estimation using a wide range of data. First, they considered a principle known as Damuth’s Law, which states that species with larger body sizes will usually have lower average population densities. Because this formula includes individuals in a species that has not reached its maximum size, the scientists used an estimate for “postjuvenate individuals” – the T. Rex equivalent of a frightened teenager. (Now there is a worrying thought.) Once they had this information, they multiplied it with the estimated geographic area in which paleontologists believe the monstrous beasts once roamed. Then they incorporated what we know about when T. Rex lived, although scientists acknowledge that this figure is particularly unclear “because of poor temporal control over most T. rex fossil sites and because there is a substantial gap in dinosaur conservation.” under the oldest T. rex fossils. “
Because experts believe that, based on fossil evidence, they lived between 1.2 million years and 3.6 million years ago, the team settled on an average of 2.4 million years. From there, they connected other numbers until they finally reached their estimates.
Despite their short reign on the planet – an unfortunate one interrupted by the Cretaceous-Triassic extinction event – the fact that another bipedal predator would conduct a census of them 66 million years later speaks of their cultural immortality.
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