At Least Some Dinosaurs Had Belly Buttons, Exquisite Fossil Just Revealed

An exquisitely preserved horned dinosaur fossil from China has the oldestbelly button found to date.

The scar is from the egg sac of a creature that lived 130 million years ago.

Within days or weeks of an egg hatching, many snakes and birds lose their scars. Alligators are kept for life by others.

This is a picture of an American alligator belly button (umbilical scar.) You're welcome #BellyButtonScience #alligator #gator #bellybutton pic.twitter.com/GZt2EhA0oD

— Dr. Anne A Madden (@AnneAMadden) February 1, 2017

The scar on the Psittacosaurus dinosaur is more similar to an alligator than it is to a reptile.

It is the first example of a belly button in a non-avian dinosaur.

It doesn't mean that all land dinosaurs have the same scar, but there is a chance.

The most important fossil we have for studying dinosaur skin is the Psittacosaurus specimen.

We can bring to life new technology with it.

There is a dinosaur fossil located in China. The first cloaca ever seen in a non-avian dinosaur is exquisitely preserved.

The individual is lying on its back with all of its information in hand.

There is a long scar on the back of a reclining Psittacosaurus. There is a design byagged Fang designs.

Researchers have been able to identify a change in the pattern of skin and scales that correspond to the location of the dinosaur's belly button.

The embryo in the egg is fed by the yolk sac and the waste is collected by the allantois. These connections seal up before an animal is born.

This is the first proof that egg-laying dinosaurs have a scar.

SMF R 4970 shows us a thin column of scales on an ancient abdomen, which is rare among dinosaurs.

The smooth margins of the scales suggest that the scar was not caused by physical trauma or disease.

It's similarity to alligators suggests we're looking at a bellybutton.

A laser image of a scar on a reptile. Bell and his team wrote about their research in theBMC Biology.

The scales around the long scar in the Psittacosaurus specimen were similar to lizards and crocodiles.

Humans have a smaller belly button than we do. The specimen is the first of its kind to preserve a belly button.

The most private parts of the fossil are on display.

The study was published in a scientific journal.