Not so fast, according to new research published Monday, arguing that T. rex should not be reclassified. Any differences in the fossils only reflect the fact that dinosaurs, like humans, came in different shapes and sizes.
“Tyrannosaurus rex remains the only true king of dinosaurs,” paleontologist Steve Brusatte, co-author of the latest analysis and professor at the University of Edinburgh’s School of Earth Sciences in Scotland, said in a press release.
“It is true that the fossils we have are somewhat variable in size and shape, but as we show in our new study, this difference is slight and cannot be used to accurately separate fossils into easily identifiable groups. Based on all the fossil evidence we currently have, T. rex stands alone as an The only giant predator from the end of the age of dinosaurs in North America.”
Comparison with “living dinosaurs”
The authors of the new report said that the analysis, which argued in favor of three types of tyrannosaurs, used a limited number of samples, incomparable measurements and inappropriate statistical techniques.
“This claim was based on a very small comparison sample. When compared with data from hundreds of live birds, we actually found that T. rex was less variable than most living theropod dinosaurs. This evidence for the proposed multiple species does not hold true for it,” said James Napoli, co-lead author. For the new study and doctoral student at the American Museum of Natural History in New York, in ed.
Gregory Poole, one of the authors of the original study and author of “The Princeton Field Guide to Dinosaurs,” said the criticism “goed too far in criticizing what was the first serious effort to examine dinosaur species.”
“There’s just something about our beloved T. rex that makes people irritable to a degree not seen with other paleotaxa. If our research paper was about species like the giant Argentine theropod Giganotosaurus, it very likely wouldn’t be much of a fanfare,” he said via email.
He added that the latest research comes as “an old propaganda that appears to be organized to defend Tyrannosaurus rex, rather than a serious exploration of the possibilities that fossil specimens of the genus Tyrannosaurus contain more than one species.”
Researchers involved in the latest paper said it was still possible that there was more than one type of tyrannosaurus that terrorized Cretaceous North America, but that there isn’t enough evidence available to make that kind of decision based on the current fossil record.
Co-author David Hoon, paleontologist and senior lecturer at Queen Mary University of London said.
The researchers emphasized that determining what makes one species different from another is a risky and complex process even among living animals.
“Living species boundaries are difficult to determine: zoologists, for example, disagree about the number of living species of giraffe,” said co-author Thomas Holtz, principal lecturer in vertebrate palaeontology at the University of Maryland, College Park, and Smithsonian National Institute of Natural History in Washington, D.C., in Statement.
“It becomes more difficult when the species in question is old and known only from a relatively small number of samples. Other sources of variance – changes with growth, with region, with sex and with old-fashioned individual differences – must be rejected before the hypothesis that two groups are accepted Of the samples the two are actually two separate species. In our opinion, this hypothesis is not the best explanation yet.”
The journal Evolutionary Biology published the research on Monday.