Fancy feathers of old

SMALL PRINT:TODAY, FEATHERS are an important feature that help birds fly, keep them warm, and, in some cases, provide camouflage so they can escape the notice of predators, or attract a mate when the bird wants to be seen.

It turns out that birds with feathers were also on the go during the time of the dinosaurs, and a new study from the US and China on a Microraptor – a pigeon-sized, four-winged dinosaur that lived about 120 million years ago – suggests its plumage was iridescent.

Feathers can appear iridescent when pigment-containing structures called melanosomes are narrow in shape and stacked in layers. The researchers looked at 26 samples from Microraptor’s plumage and found melanosomes in 20 of them. Then they compared the patterns of Microraptor melanosomes to those seen in a wide range of bird species that are living today. The results suggest that the Microraptor’s feathers were iridescent with a glossy sheen.

“Modern birds use their feathers for many different things, ranging from flight to thermoregulation to mate-attracting displays,” said co-author Matt Shawkey from the University of Akron in a statement. “Iridescence is widespread in modern birds and is frequently used in displays. Our evidence that Microraptor was largely iridescent thus suggests that feathers were important for display even relatively early in their evolution.” The fossil also bears a narrow tail which is adorned with feathers.

Writing in the journal Science, the study authors suggest the dinosaur’s flashy garb had a role in signalling. “Although we cannot assign a definitive function to iridescence in Microraptor, a role in signalling aligns with data on the plumage of [the Microraptor fossil].”