Credit...Science Photo Library/Science Source
The New York Tmes has a story about how many Tyrannosaurus rex ever lived. Actually, this story showed up in numerous places.. SciTechDaily, USA Today, NBC, etc. Apparently, it's big news that about 2.5 billion total T rex roamed the Earth during the time their species existed! The original paper appeared in the journal Science.
Before they were killed off by a meteor that hit Earth 66 million years ago, some 20,000 adults of the iconic ferocious dinosaur predator — Tyrannosaur rex — roamed North America at any given time, researchers have calculated.
That’s not a precise number, and the correct total could be far lower or higher because of uncertainties like how long they lived, how quickly they grew and matured and the rate of their metabolisms. Still, the research, published on Thursday by the journal Science, opens doors in studying long-extinct dinosaurs beyond what can be gleaned from individual fossils.
Skeletal features can tell a lot about an animal. For example, someone looking at a human tooth could infer that it is suited for chewing both plants and meat, and the shape of the skeleton could yield an estimate of how fast a person can run. But the physical attributes cannot tell you how many people live in New York City.
“Studies like this are the first step in recreating ancient ecosystems,” said Felisa A. Smith, a biology professor at the University of New Mexico who was not involved with the research. “We need to move beyond what fossils were found and where to the larger picture: how the ecosystem functioned.”
Charles R. Marshall, a professor of integrative biology at the University of California, Berkeley who led the research, said the work started with him wondering, when he held a T. rex fossil, how rare was that?
“Were there are a million, a billion, a trillion T. rexes?” he said. “Is this one in a million, one in a billion, one in a trillion? How on earth could we know that number? We all know fossils are rare, but how rare are they? And so it really started with that question.”