Credit...Mark Witton
The New York Times Science column has a story about Tyrannosaurus rex. Back in February 2022, a paper in the journal Evolutionary Biology proposed that Tyrannosaurus rex is actually three distinct species - Tyrannosaurus rex, Tyrannosaurus imperator, and Tyrannosaurus regina. The paper pointed to differences like number of "incisor" teeth and whether the animal was gracile or robust as the distinguishing features. The proposal was met with much skepticism in the paleontology community. Now, we have a rebuttal, which also was published in the journal Evolutionary Biology. The authors of this paper include some of the most respected names in Dinosaur research (Thomas D. Carr, James G. Napoli, Stephen L. Brusatte, Thomas R. Holtz, David W. E. Hone, Thomas E. Williamson, and Lindsay E. Zanno. Four of which have spoken at ESCONI meetings!) They address the claims of the previous paper, stating the "The results showed that the absolute variation in Tyrannosaurus is unexceptional and it does not indicate cryptic diversity. We conclude that “T. regina” and “T. imperator” are subjective junior synonyms of T. rex."
The proposed T. rex reclassification struck the paleontology community like an asteroid, igniting passionate debates. On Monday, another team of paleontologists published the first peer-reviewed counterattack.
“The evidence was not convincing and had to be responded to because T. rex research goes well beyond science and into the public sphere,” said Thomas Carr, a paleontologist at Carthage College in Wisconsin and an author of the new rebuttal. “It would have been unreasonable to leave the public thinking that the multiple species hypothesis was fact.”
The earlier team of researchers have anticipated the rebuttal, which was published in the journal Evolutionary Biology. Gregory Paul, one of the authors of the original study, is working on another paper and says many of the rebuttal’s claims are outlandish.
“I don’t like flat-earthism because the evidence is against it,” said Mr. Paul, who is an independent researcher and influential paleoartist. “It’s the same here: the evidence indicates very strongly that there are multiple species.”
This king-size taxonomic debate seems destined to rage for epochs. Which is unsurprising considering how difficult it is for researchers to differentiate prehistoric species. Without dino DNA, the lines between one fossil species and another are messy. So paleontologists measure different traits, like the size and shape of a particular bone. However, the fossils can be misleading, as spending eons entombed underground can distort bone. And this is before considering how sexual differences, injuries, illness and natural variation sculpt bones during the animal’s lifetime.
