“ How manyTyrannosaurus rexwere there ? ” It ’s a question that ’s been answered before , but a cogitation publish last month offers up a new trope , challenging previous assumption .

From the daybreak of the dinosaurs until their extinction , 1.7 billion of thethin - lipped , intimidatinglyclever , andsurprisingly slowtheropods drift the Earth , according to the new and improved reckoning .

Aprevious studyfrom 2021 put the all - clip entire number of “ tyrant lizards ” at 2.5 billion , but this most late newspaper , published almost precisely two years to the Clarence Day later , suggests there may really have been far fewer .

The late estimation is by no means measly – 1.7 billion is still a lot of dinosaur , after all . But what happened to those other 800 million ?

The unexampled example , created by Eva Griebeler , an evolutionary ecologist at the Johannes Gutenberg University Mainz , attempt to cover some of the “ shortcomings ” of the original study , and as a result , has move around out a much small trope .

“ Unlike my mannequin , ” Griebeler writes , “ the contemporaries time as well as sprightliness expectancies , gross replica rates , and procreative values of individuals calculated from the previous model all strongly contradicted our current understanding of the biology ofT. rexand of other theropods . "

" Their values also disagreed with those of large extant reptile , dame and mammalian . ”

take all this into consideration , Griebeler created an update model , which calculated thatT. rexwereT.rex - ing for rough 90,000 generation , each of which had around 19,000 individual . Tallying this up devote the maximum number ofT. rexas 1.7 billion .

The late model , on the other hand , estimated there to be a total of 127,000 generations ofT. male monarch , each with approximately 20,000 somebody .

Fortunately , it seems there is no spoiled blood between the authors of the two studies : Charles Marshall , lead writer of the 2021 paper , conceded that Griebeler ’s is a " more realistic " approximation , Live Sciencereports .

Either way , 1.7 or 2.5 billion , there ’s still a Brobdingnagian number ofT. rexmissing from the dodo record . If Griebeler ’s poser is correct , then only one fogey has been recovered per 52.5 million individuals , solicit the doubtfulness : Where are they ?

It ’s just one of themany mysteriessurrounding arguably the most famous of the dinosaurs , about whom we arestill learningso much .

The study is published inPalaeontology .

[ H / T : Live Science ]