The models pointed to one dinosaur for every 100 square kilometers (38.6 square miles). They estimated T. rex roamed over about 2.3 million square kilometers (888,000 square miles), and the species existed for about 2.5 million years.
From that, the team calculated a standing population size of 20,000. Over a total of about 127,000 generations, each lasting about 19 years, about 2.5 billion individual T. rexes lived overall.
Marshall pointed out that uncertainties in the estimates are large. The actual number of tyrannosaur rexes living at any one time could be as few as 1,300 and as many 328,000. That means that over the lifetime of the entire species, there could have been anywhere from 140 million to 42 billion
LCDFlight wrote:What if they meowed like kitty cats?
Aesma wrote:Knowing how many there were at any one time, on average, is interesting, knowing how many there were across millions of years, not so much.
How many humans by that account ?
BlueberryWheats wrote:But how do you define when a t-rex is a t-rex? I mean, it would have evolved from an earlier ancestor, but where is the boundary?
Humans obviously evolved from earlier apes, but it's not like one day humans turned up. It would have been a slow gradual evolution.
NIKV69 wrote:If there was so many wouldn't we find more fossils?
Once remains are buried under sediment, their decomposition slows down due to a lack of oxygen, giving enough time for fossilisation to occur.
But dinosaurs lived on land, so how did they get buried quickly enough for some of them to fossilise?
Dr David Button, a dinosaur researcher at the Museum, says, 'Most of the dinosaur fossils we find are from animals that were living near to a lake or river.
'Some died shortly before the area flooded and covered their remains in mud and silt. Others were washed into a river by heavy rain.'
casinterest wrote:NIKV69 wrote:If there was so many wouldn't we find more fossils?
We are lucky to find what we do find.
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