Paleontologists have shown what the navel of a dinosaur looked like

Paleontologists in China examined the integument of a well-preserved Psittacosaurus specimen and found an umbilical scar. New Atlas writes about it.

A strikingly preserved navel-bearing Psittacosaurus fossil that lived about 130 million years ago, and which led to this conclusion, was found in China in 2002 and given the designation SMF R 4970.

In mammals, the navel is the result of the detachment of the umbilical cord at birth. But reptiles and birds, the method of reproduction of which is to lay eggs, do not have such a cord. Inside the egg, the abdomen of the fetus is connected to the yolk sac and other membranes. A scar occurs when the embryo separates from these membranes just before or during hatching from the egg. Known as an umbilical scar, this is a non-mammary form of the navel. And that's exactly what an international team of scientists says they found in this fossil.

Scientists have made out the umbilical scar thanks to a new method - imaging with laser stimulation of fluorescence (LSF).

The researchers compared the length of his femur with that of other specimens for which the age is known, and concluded that at the time of death he was six or seven years old (that is, he was almost an adult).

Thus, in this dinosaur, the umbilical scar was preserved in the adult state, experts noted.

Psittacosaurus are representatives of the infraorder of horned dinosaurs that lived in the early Cretaceous period on the territory of modern Asia.