Rare dinosaur skin offers insights into evolution

Mauricio Barbi has loved dinosaurs for as long as he can remember and dreamed of one day being a paleontologist. “When I was a kid, I loved space, stars, and dinosaurs,” he said.

Fast-forward a few years, and Barbi is trekking through the Alberta Badlands alongside famous paleontologist Philip Currie, whose professional life became the inspiration for characters in the Jurassic Park movies. During this fieldwork, he also met paleontologist and rising star, Phil Bell, who had recently found a well-preserved hadrosaur. When he joined Bell in the excavations, Barbi was shocked and thrilled by what they discovered.

“Understanding what life used to be like on our planet is extremely important, but very difficult to piece together. When you look far back in time, there isn’t much left over. If you’re lucky, there are bones left, but even those fossilize into rock over millions of years,” he said.

On the dig, the team of scientists discovered what they initially thought was an imprint of dinosaur skin. What they actually found was something much rarer—patches of well-preserved 3-dimensional skin from a 72-million-year-old hadrosaurid dinosaur.

“I wouldn’t have expected to find that in a million years,” said Barbi, who is an experimental high energy particle physics professor at the University of Regina and works on neutrino physics experiments in different parts of the world. “This sort of thing is extremely rare to find and the condition of preservation is absolutely astonishing.”

At first, they did not know what they had found. “When I first held the sample, I noticed it was three dimensional and not likely an imprint. With an electron microscope, I could tell that there was an organized distribution of carbon and it seemed to be in layers, but I was suspicious,” he commented.

He and his colleagues then went to the Canadian Light Source (CLS) at the University of Saskatchewan and used non-destructive synchrotron light to analyze their sample at the atomic and molecular level.

“It was a no-brainer for me,” said Barbi. “The CLS provides dense beams of radiation that comes in several types of wavelengths. With X-rays, you can look at very tiny structures like atoms, with infrared you can look at larger structures like organic molecules. The CLS can provide these capabilities all in one place and produce a lot of data in a short interval of time.”

Using several beamlines and techniques, it became clear that the sample had layers made of small, semi-circle structures that very much resembled cells.

Barbi and colleagues also tried to piece together what had happened to this dinosaur and how its skin was so well preserved.

“The environment in which the dinosaur was found had a lot of crystallized plants,” he commented. This helped to explain what a herbivore was doing there. Also, the region had a river and the dinosaur was likely partially covered by water during its decay.

Water tends to slow decay because there is less oxygen for bacteria to feed on. “The specimen also showed evidence of mud associated with the skin, which can help in the mummification of animals,” he said. Iron in the muddy sediment likely helped in the preservation of the tissue.

The team also used the CLS to compare the dinosaur skin with the skin of modern animals, including a crocodile, rat and chicken. “This is the first time this has ever been done at this level,” said Barbi.

“We study evolution based on what animals looked like. We can guess how things were based on bones and impressions of ligaments and imprints left in materials such as mud, but this was the first time we could directly compare the layout of cell layers in dinosaurs to living creatures,” said Barbi. “This helps us understand how animals have evolved. It’s astonishing.” In this case, the hadrosaur from the Late Cretaceous period in Alberta had skin that very closely resembles the skin of a modern crocodile.

“What is funny about this research is that when I started doing this, I was not looking for cell layers. I was looking for pigments to see if we could tell the colour of that dinosaur. Then, we found something much better,” he stated.

“It opened our eyes to the possibilities. We need to look more carefully at other well preserved specimens to see what is actually there,” he concluded. “I hope this work will send a message to other scientists to look more carefully at these kinds of things and do a more in-depth analysis, using different techniques.”

This international collaboration involved researchers from the CLS; Universities of Saskatchewan, Regina, and Alberta; University of New England, in Australia; and Università di Bologna, in Italy. They used several beamlines at the CLS, including SM, SXRMB, VESPERS, BMIT and MidIR to collect data about their sample.

By piecing together the puzzle of what happened millions of years ago, Barbi hopes we can also learn more about the future of our planet. In the process, he gets to fulfill his childhood wish to work with dinosaur fossils.

“I used my knowledge in physics and all of a sudden I was making discoveries in paleontology and doing field work and working alongside the people I admired,” he said. “It has been a dream come true.”

“Now, I want to go to Mars,” said Barbi. “It probably will never happen, but you never know.”

Barbi, Mauricio, Phil R. Bell, Federico Fanti, James J. Dynes, Anezka Kolaceke, Josef Buttigieg, Ian M. Coulson, and Philip J. Currie. "Integumentary structure and composition in an exceptionally well-preserved hadrosaur (Dinosauria: Ornithischia)." PeerJ 7 (2019): e7875. DOI: 10.7717/peerj.7875.

At the time of this release, this paper is in the top 5% of all research outputs scored by Altmetric.

 

For more information, contact:

Victoria Schramm
Communications Coordinator
Canadian Light Source
306-657-3516
victoria.schramm@lightsource.ca