(ORDO NEWS) — Reanalysis of the remains of Tyrannosaurus rex showed that this species can probably be divided into three groups of dinosaurs. They differ in the structure of the femurs and teeth, as well as the period of existence.
Tyrannosaurus rex is the only species of the genus Tyrannosaurus recognized by the scientific community . However, scientists have already confirmed some differences in the structure of the bones and teeth of the discovered specimens.
Now a team of American researchers has re-analyzed the remains of a Tyrannosaurus rex. They revealed new differences in the structure of the femur and teeth in different individuals. This may indicate that the name T. rex has combined several different types of tyrannosaurs.
The scientists analyzed the bones and teeth of 37 Tyrannosaurus rex specimens. The femurs were preserved in 24 individuals, and the authors were able to assess their strength.
This indicator was calculated based on the length and circumference of the bone. In addition, the scientists measured the diameter of the base of the teeth and estimated the space they occupied in the gums to determine how many thin incisor teeth the dinosaurs had.
The structure of the femur varied greatly among individuals: in some it was thicker and stronger, in others it was thinner and more fragile. The first group was twice as numerous as the second. That is, the difference between them cannot be explained by gender, since in this case the distribution would be approximately equal.
The differences were also not related to the age of the tyrannosaurs: some juveniles had strong bones, while adults had thin ones. The structure of the teeth was also different, although they were preserved in only 12 specimens. Single incisor specimens were more likely to have thin femurs.
Then the scientists analyzed the layers of sediments in which the remains of tyrannosaurs were found. It turned out that in the lower, most ancient layer, only strong bones of tyrannosaurs were found. In the middle layer of sediments, only one specimen with thin bones was preserved, and all the other representatives of this group rested in the uppermost layer.
It is likely that originally there was only one species of Tyrannosaurus rex with strong bones, and changes over time led to the appearance of other species.
The authors of the work suggested isolating the ancient tyrannosaurus rex with strong bones and two incisors into the species Tyrannosaurus imperator (“emperor”), and the later species with thin bones and one incisor to be called Tyrannosaurus regina (“queen”).
The remains of the recognized species Tyrannosaurus rex (“king”) were found in the upper and middle layers of sediments. Apparently, he combined the features of the other two species: he had both strong bones and only one incisor.
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