In the United States discovered a pregnant tyrannosaurus aged over 60 million years
American researchers from the University of North Carolina discovered the remains of a pregnant female Tyrannosaurus Rex in Montana. The fossil age is about 60 million years. Historians have come close to identifying a criterion by which one can determine the sex of ancient reptiles.
Paleontologists were able to establish that shortly before her death, the female Tyrannosaurus was preparing to lay eggs, due to the presence of traces of medullary bone in her. It is only in females of birds and serves as a source of calcium, from which the shell is formed.
Earlier it was reported that historians are increasingly inclined to the fact that modern birds are descendants of dinosaurs. In particular, successful experiments are being carried out to grow chickens with paws, like in ancient animals.
To determine the sex of a tyrannosaur who lived about 60 million years ago, scientists subjected his remains to chemical analysis.As a result, traces of a substance called keratan sulfate, an important component of the medullary bones, were found.
Tyrannosaurs belong to theropods, two-legged ancient lizards. Most of them were predators. The largest representatives of this species were spinosaurs, reaching 17 meters in length. Recently, birds have also been attributed to theropods.