Feathers of different colours have been found on a fossilised pterosaur skull, hinting that an ancestor of these winged reptiles had feathers far earlier than we thought
Pterosaurs – flying reptiles that cruised the skies millions of years ago – may have had multicoloured feathers. We know that some dinosaurs, which are cousins of pterosaurs, had feathers like this, but the discovery of feathers with different colours on a pterosaur indicates that feathers may have come about 100 million years earlier than researchers previously thought, earlier even than flying vertebrates.
Maria McNamara at University College Cork in Ireland and her colleagues found these preserved feathers on a fossilised partial pterosaur skull that was held in a private collection and was originally excavated in Brazil. Specimens of this particular species, Tupandactylus imperator, have prominent crests on their heads; the feathers on this skull were found on either side of the crest.
The researchers found two types of feathers: whisker-like monofilaments and more complex branching feathers. When examined under a microscope, each type of feather contained different sorts of melanosomes, tiny pieces of cells that synthesise and store the pigment melanin.
“The monofilaments have these elongated, sausage-shaped melanosomes, but the branched feathers have these more stubby, fat melanosomes,” says McNamara. “The melanosome shape is really closely linked to its chemistry and thus its colour.”
By comparing these melanosomes with those found in modern feathered animals, the researchers determined that the bristly monofilaments were probably black or dark brown, while the fluffier branched feathers were probably a lighter shade of brown.
“The specific colours don’t really matter from an evolutionary sense; what matters is that they have these different colours,” says McNamara. “It probably means that the ability to impart colour is something that’s really ancient and that’s tied up in the whole way that feathers were evolved.”
Because both pterosaurs and some dinosaurs had multicoloured feathers, the feathers were probably passed down from a common ancestor in the early Triassic period, around 250 million years ago, she says.
“[This finding demonstrates that] feathers arose long before flight, and so must have been for insulation or signaling,” says Michael Benton at the University of Bristol, UK. If the feathers were all the same colour, they might have been used only for insulation, but the finding of multiple colours indicates that they were probably used for signaling as well, perhaps for camouflage or attracting mates.
Journal reference: Nature, DOI: 10.1038/s41586-022-04622-3
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