An ancient bird that lived 120 million years ago had fancy tail feathers like a peacock, a study of fossilised remains shows.
Researchers in China and the US report the discovery of Yuanchuavis kompsosoura, a bird precursor with elaborate feathers that would have helped attract it a mate.
Its remains, including well-preserved tail feathers, were taken from the 120 million-year-old deposits of the Jehol Biota in northeastern China, known as China's 'Jurassic Park'.
Y. kompsosoura was a small bird, about the size of a blue jay, but its pair of elaborate tail feathers reached more than 150 per cent the length of its body.
While its tail feathers helped it find a partner, they didn't make flying very easy, meaning it had to avoid open environments due to the risk of being unable to fly away from predators.
Artist's impression of the Mesozoic bird Yuanchuavis kompsosoura, as it would have appeared 120 million years ago. The researchers named it Yuanchuavis after Yuanchu, a bird from Chinese mythology. It had a fan of short feathers at the base and then two extremely long plumes
Y. kompsosoura belonged to an extinct group called the Enantiornithines, which looked like modern birds, except they had teeth and clawed fingers on each wing.
Enantiornithines vanished in the mass extinction that wiped out the dinosaurs around 66 million years ago.
The study authors have named this new species named it Yuanchuavis after Yuanchu, a bird from Chinese mythology.
'We've never seen this combination of different kinds of tail feathers before in a fossil bird,' said study author Jingmai O'Connor, a paleontologist at Chicago's Field Museum.
'It had a fan of short feathers at the base and then two extremely long plumes. The long feathers were dominated by the central spine, called the rachis, and then plumed at the end.
'The combination of a short tail fan with two long feathers is called a pintail, we see it in some modern birds like sunbirds and quetzals.'
According to the researchers, the elaborate ornaments represent the battle between survival and sexual selection at an early point in natural history.
The tail feathers would have made more noticeable to a potential mate, but worse at flying or more noticeable to its predators.
(A) Photograph of Yuanchuavis kompsosoura fossil from the Jehol Biota in northeastern China and (B) line drawing of the remains
Cranial anatomy of the species. Y. kompsosoura belonged to an extinct group called the Enantiornithines, which looked like modern birds, except they had teeth and clawed fingers on each wing