The discovery last year of Kulindadromeus, which had both scales and feathers, prompted speculation that this may have been the case for all dinosaurs. Photograph: Andrey Atuchin /SWNS.com

Did dinosaurs have a feathery covering?  That’s what a story in The Guardian discusses.  In recent years, researchers have been discovering more and more evidence that feathers were more common than previously thought.  However, a new study led by Nicolas Campione of the  Uppsala University in Sweden shows that most of the dinosaurs were probably covered in scales.  The original paper was published in the journal Biology Letters of the Royal Society.

Nicolás Campione, a dinosaur researcher at Uppsala University in Sweden, worked with scientists at the Natural History Museum in London and the Royal Ontario Museum in Toronto to survey some of the best-preserved dinosaur fossils from museums around the world.

The scientists collected information on around 75 species that are known from the fossil remains of their soft tissues to have had either scales or feathers. From these, they created a dinosaur family tree and used a statistical model to work out the odds of species having feathers at different points in dinosaur history.

“What we found from this analysis is that the first dinosaur was probably not feathered,” said Campione. “Feathers clearly evolved in the dinosaur lineage, but right now, the data do not point to a feathered ancestor for them all.”

The first dinosaurs evolved from reptiles more than 230 million years ago. Feathers are thought to have arisen more than once in dinosaur lineages, and while they live on and give flight to modern birds, feathers first emerged for other reasons: for warmth or to provide colourful plumage displays.