Researchers have discovered traces of red blood cells and collagen fibers in a dinosaur fossil from 75 million years ago. This discovery could shed light on dinosaur physiology, namely whether some species were warm-blooded or cold-blooded. More details about the discovery can be found in the journal Nature Communications.
Scientists have discovered intact soft tissue in dinosaur fossil before. A famous discovery was the one made by Mary Schweitzer at North Carolina State University. In 2005 she analyzed the leg of a Tyrannosaurus rex fossil and discovered flexible, transparent collagen.
What is special about this latest discovery is the fact that the cells and the collagen were discovered in specimens which the researchers described as “crap”. If they were able to identify surviving soft tissue in such fossils this means that impressive remains like the ones in museum collections could present troves of soft tissue.
The researchers from the Imperial College London examined a dinosaur claw fossil and identified small ovoid structures with a core which was denser and was similar to red blood cells. Another fossil fragment was found to preset fibrous characteristics with a banded structure very much like the one observed in nowadays collagen present in ligaments, tendons and skin.
Paleontologist Susannah Maidment from the Imperial College London said:
“It’s really difficult to get curators to allow you to snap bits off their fossils. The ones we tested are crap, very fragmentary, and they are not the sorts of fossils you’d expect to have soft tissue.”
The fossils were collected last century from the ground at the Dinosaur Park Formation in Canada. In order to analyze them the investigators broke small pieces off the fragment and revealed fresh surfaces inside.
Maidment asked Sergio Bertazzo to analyze the fossil using a series of electron microscope techniques. Bertazzo is a materials scientist also from the Imperial College London who was studying how calcium builds up in human blood vessels. To his surprise he discovered something which looked like blood.
At first the scientists thought that the blood was in fact historic contamination and it belonged to a collector or curator which had an injury when they handled the specimen. In order to rule out this possibility they checked whether the cell had a nucleus or not. Mammal blood cells lack a cell nucleus, but the cells identified on the fossil presented a nucleus which means that the blood was not from humans.
Bertazzo said that that further research is needed in order to confirm that their initial observation is correct
Image Source: Science News