Tea. rex still reigns as king of the dinosaurs, according to scientists, who argued Monday against a controversial hypothesis advanced this year that the mighty meat-eating Tyrannosaurus should be recognized as three species, not just one. In form of.
In research published Monday, seven paleontologists said a March study offered insufficient evidence to show that there were three Tyrannosaurus species based on fossils of the world’s most famous dinosaurs, due to improper statistical methods, limited comparative specimens and faulty measurements. was referring to.
T. rex has been the single species in the genus Tyrannosaurus, which was first described as a dinosaur in 1905. A species is a broader group of related organisms than a single species.
Three other researchers said in an earlier study published in the same journal that the three species should be recognized on the basis of variation in the thickness of the thighbones and the size of the lower front teeth among about three dozen Tyrannosaurus specimens.
“The evidence needs to be convincing, and suddenly dividing an iconic animal like T. rex, which has been known for more than a hundred years, into different species requires a high burden of proof. It is true that T. rex bones vary in size and shape, but in our new study we show that this variation is minimal,” said paleontologist Steve Brusset of the University of Edinburgh, who co-authored the new study in the journal Evolutionary Biology.
Tyrannosaurus, part of a group called theropods that included all carnivorous dinosaurs, had a massive head and tremendous bite force, walked on two strong legs, and had short arms with just two fingers.
The new study looked at inter-species variation in thigh thickness in four other meat-eating dinosaurs and 112 species of living birds, descendants of small feathered theropods, finding that Tyrannosaurus variations were exceptional.
“It is normal for any species to be variable in size and shape. Look at the height and waist lines and teeth grin in people today, who are all members of the same species. Therefore t. rex’s bones and teeth are so minor that they resemble T. rex into multiple species,” Brussett said.
Tyrannosaurus roamed western North America during the Cretaceous period in the twilight of the dinosaur age before colliding with an asteroid on Mexico’s Yucatan Peninsula 66 million years ago, dooming the dinosaurs.
“Tyrannosaurus rex remains a true king of the dinosaurs. This giant apex predator is the only species of dinosaur that lived in North America at the end of the Cretaceous,” Brusatte said.
In addition to the species T. rex, meaning “tyrant lizard king,” Baltimore-based independent paleontologist and paleoartist Gregory Paul and two colleagues proposed two additional species: T. Imperator, meaning “tyrant lizard emperor,” and T. Regina, which means “tyrant lizard queen.”
Paul criticized the new work as hasty and “not a proper scientific study”.
Paul said, “This turns out to be a form of paleopropaganda that appears to have been structured to protect T. rex, rather than to seriously explore the possibility that fossil specimens of the genus Tyrannosaurus contained more than one species.” Certainly the genus did.”
“There’s something about dear T. rex that causes people to excite to a degree not seen with other palaeotaxes (ancient creatures). If our paper was about a species of, say, giant Argentine theropods Giganotosaurus also doesn’t get too fussy and annoying,” said Paul.
Perhaps the largest known Tyrannosaurus is a specimen named Sue, 40-1/2 feet (12.3 m) long, at the Field Museum in Chicago.
“We are open-minded that there may be multiple species of Tyrannosaurus,” Brusatte said. “We just need more and better fossils. The number of fossils in their dataset is so small that it is hard to find any consistent way to divide Tyrannosaurus into multiple species based on clear, easy-to-define, consistent differences.”