Some pterosaurs were covered by a diverse coat of different feather- and fur-like structures, suggests a paper published online this week in Nature Ecology & Evolution.

Early feathery structures were previously thought to be unique to the group of dinosaurs that includes the ancestors of modern-day birds. Instead, pterosaurs - the first vertebrates to achieve flapping-powered flight - are typically depicted by researchers as having fur.

Baoyu Jiang, Michael Benton and colleagues used microscopic and spectroscopic imaging techniques to study the fossilized remains of two well-preserved, short-tailed pterosaurs that lived in what is now China around 160-165 million years ago. The authors found that these pterosaurs had four different kinds of covering - including fuzzy, fur-like insulating structures over their heads, torsos, limbs and tails; and, on parts of the head and wings, three types of curved, thread-like fibres similar to modern feathers.

The different coverings are likely to have played functional roles in heat regulation, sensing, signalling and aerodynamics. The finding that pterosaurs had feather-like structures suggests either that feathers are either ancestral to both dinosaurs and pterosaurs, or that they evolved independently in both lineages.

In an associated News & Views article, Liliana D’Alba writes that, with future improvements in scanning electron microscopy, we may expect more insights into what exactly dinosaurs and pterosaurs looked like in life.