Posted for Nicola Jones.

Okay, we still don’t know the answer to that question (sorry to tease you), but we do now have another good sample of one beast’s skin, helping to determine what it was like in most ways except colour.

The fossil of a plant-eating Psittacosaurus (aka ‘parrot-lizard’) unearthed in China shows a folded layer of skin where the cross-section could be examined. This revealed that the beast had tough, scaly skin with more than 25 layers of collagen – similar to that of today’s sharks and reptiles.

The perhaps-more-interesting question of whether scales or early prototypes of feathers topped this skin is more tricky…

The BBC takes a middle line on this, saying it could have been either. But lead author of the paper in Proceedings of the Rodayl Society B, Theagarten Lingham-Soliar of the University of KwaZulu-Natal in South Africa, comes down firmly on the side that this collagen material refutes the notion that there was anything like feathers there.

“Scientists must really now choose – belief in the nebulous idea of protofeathers or the reality of collagen, the dominant protein in vertebrates,” Lingham-Soliar told the Telegraph. “I am convinced from the nonsense spouted by many of the people who denounce collagen in favour of protofeathers that they have never actually seen collagen in its natural or decomposing state.”

Lingham-Soliar has previously reported on another fossil that he said threw the feather theory into doubt in May 2007 (see Bald dino casts doubt on feather theory; subscription needed). But despite his tone of finality on the subject, this doesn’t change most researchers’ notion that some dinos did indeed have feathers. And certainly it’s clear that birds are their descendents. The real question is when and why feathers evolved.