A high-profile discovery of T Rex tissue is nothing of the sort, according to a paper published today in PLOS One.

Thomas Kaye of the Burke Museum of Natural History in Seattle says what have previously been presented as remnants of blood vessels are actually just modern bacterial slime.

“Mineralized and non-mineralized coatings were found extensively in the porous trabecular bone of a variety of dinosaur and mammal species across time,” write Kaye and colleagues. “They represent bacterial biofilms common throughout nature.”

A combination of electron microscope work and carbon dating on dino bones shows that what others have identified as ‘blood vessels’ are actually just casts formed by bacteria inside bones, they say.

“We are not experts in the field. We are not disagreeing with the fact that their instruments detected protein,” Kaye told Reuters. “We are offering an alternative explanation.”

Mary Schweitzer, a North Carolina State University researcher who reported dino soft tissue in 2005, has rejected the claims. “The idea that biofilms are completely and solely responsible for the origin or source of the structures we reported is not supported,” she told USA Today.

Over on Wired, Dixie State College of Utah paleontologist Jerry Harris is keeping the peace:

The field of investigating fossil bones at this scale and with these kinds of procedures is still so new that there really isn’t a substantial enough body of data yet for people to even argue about. That the two produced different results doesn’t necessarily mean either one is wrong. It simply means that lots of questions remain unanswered.

Image: stock photo / Alamy