Paleontologists Discover Fossils Showing Dinosaurs Had ‘Navels’

3D reconstruction of Psittacosaurus shows an umbilical. Image credit: Jagged Fang Designs / via CUHK

Thanks to an “incredible” fossil, paleontologists have confirmed that dinosaurs did indeed have a navel, and at the same time set a new record for the oldest ever found in reptiles and mammals.

Scientists from the Chinese University of Hong Kong (CUHK) and international colleagues in Argentina and the United States used high-tech laser imaging technology to make the discovery.

Technology has revealed the fine details of a 125 million year old dinosaur fossil discovered 20 years ago in China, which included a scar among the scales.

Dr. Michael Pittman, an assistant professor in CUHK’s School of Life Sciences, applied the laser stimulated fluorescence (LSF) technique to a fossilized skin specimen of a Psittacosaurus, a two-legged plant eater of two meters long (6.5 feet) and lived during the Cretaceous period.

“We identified distinctive scales that surrounded a long umbilical scar in the Psittacosaurus specimen, similar to some living lizards and crocodiles,” said Pittman, corresponding co-author of the study.

“This specimen is the first dinosaur fossil to retain a navel, which is due to its exceptional state of preservation.”

RELATED: ‘Impossible Fossil’ preserves exact moment when dinosaurs died : ‘It’s absolutely crazy’

Unlike humans, dinosaurs did not have an umbilical cord because they laid eggs. Instead, the yolk sac of dinosaurs was attached directly to the body through a slit-like opening, also present in other egg-laying land animals.

It was this opening that sealed around the time the animal hatched, leaving a distinctive long umbilical scar that scientists still call a navel.

The laser stimulated fluorescence image shows an umbilical scar. Image credit: Bell et al 2022 / via CUHK

While the egg-laying nature of dinosaurs predicts a long navel scar, this study is the first to support this hypothesis with fossil evidence.

SEE: Perfectly preserved embryo found inside a fossilized dinosaur egg

“While this magnificent specimen has caused a stir since its description in 2002, we have been able to study it in a whole new light using new laser fluorescence imaging, which reveals the scales in incredible detail,” said Dr Pittman. .

Dr Phil R. Bell of the University of New England in Armidale, Australia, lead and co-corresponding author of the study, commented: “This specimen of Psittacosaurus is probably the most important fossil we we have to study the skin of dinosaurs. But it continues to yield surprises that we can bring to life with new technologies like laser imaging.

The specimen is on display at the Senckenberg Museum in Frankfurt, Germany.

CHECK: A dinosaur unearthed in Argentina could be the largest animal that has ever walked on Earth

The results were published in the international biology journal BMC Biology.

SHARE the strange news with paleo-heads on social media…

Leave a Comment