Researchers Suggest , Tyrannosaurus Had 3 Separate Species, , Not Just Rex.<br />A group of researchers now believe that <br />Tyrannosaurus actually consisted of three <br />separate species and not just a single T. rex. .<br />Reuters reports that the T. rex has <br />long been recognized as the sole genus <br />of Tyrannosaurus since its discovery in 1905. .<br />Independent paleontologist and paleoartist <br />Gregory Paul and his team examined the remains <br />of about three dozen Tyrannosaurus fossils. .<br />Their research led to the recognition of two additional species: , T. imperator, meaning "tyrant lizard emperor," <br />and T. regina, meaning "tyrant lizard queen.".<br />After over a century of all specimens <br />being placed into one species without <br />the issue being carefully examined, <br />the first and only analysis finds that <br />the variation in Tyrannosaurus <br />is beyond the norms for dinosaurs, , Gregory Paul, Independent paleontologist <br />and paleoartist, via Reuters.<br />... and is distributed over time <br />in a manner that indicates that <br />Darwinian speciation from one <br />(species) to two new species <br />had occurred before the <br />final dinosaur extinction <br />cut off further evolution, Gregory Paul, Independent paleontologist <br />and paleoartist, via Reuters.<br />Reuters reports that Tyrannosaurus <br />roamed western North America <br />until about 66 million years ago. .<br />According to Reuters, there remains some <br />disagreement among paleontologists. .<br />Critics of the study claim that the variations <br />are not enough evidence to clearly define<br />a new species of Tyrannosaurus. .<br />It's hard to define a species, even for animals <br />today, and these fossils have no genetic <br />evidence that can test whether there were <br />truly separate populations. Until I see much <br />stronger evidence, these are all still T. rex <br />to me, and that's what I'll be calling them, Steve Brusatte, University of Edinburgh <br />paleontologist, via Reuters.<br />It's hard to define a species, even for animals <br />today, and these fossils have no genetic <br />evidence that can test whether there were <br />truly separate populations. Until I see much <br />stronger evidence, these are all still T. rex <br />to me, and that's what I'll be calling them, Steve Brusatte, University of Edinburgh <br />paleontologist, via Reuters
