Anchiornis's complicated pattern of reddish brown, black, gray, and white feathers may have been useful in attracting mates or some form of visual communication, as is often the case in living birds, researchers speculate.
The new find's implications for the evolution of feathering and flight are "striking," said study co-author Julia Clarke, a vertebrate paleontologist at the University of Texas in Austin.
Anchiornis shows that, "when elongate feathers first appear [in the fossil record], they are already distinctively spotted and striped," Clarke said. "We now have patterns within individual feathers in dinosaurs long before we get some kind of aerial locomotion."
Ornithologist Richard Prum of Yale University added that "a more likely function"—other than flight—"for both the crown and limb feathers of Anchiornis is communication or signaling.
"This could have been in lots of contexts, including sexual display, territoriality, et cetera," Prum said. "It could also have been like modern redstarts, which use their bright wing and tail patches to scare up insects, which [the birds] then seize in flight."