Survival of the SEXIEST! Fancy tail feathers on a newly-discovered species of peacock-like bird that lived 120 million years ago suggest it prioritised finding a mate over flying
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
'Scientists call a trait like a big fancy tail an "honest signal", because it is detrimental, so if an animal with it is able to survive with that handicap, that's a sign that it's really fit,' said O'Connor.
'A female bird would look at a male with goofily burdensome tail feathers and think, "Dang, if he's able to survive even with such a ridiculous tail, he must have really good genes".'
Y. kompsosoura's tail fossils suggest it lived in dense forest during the Early Cretaceous period (145 million years to 100.5 million years ago).
'Birds that live in harsher environments that need to be able to fly really well, like seabirds in their open environment, tend to have short tails,' said O'Connor.
'Birds with elaborate tails that are less specialised for flight tend to light in dense, resource-rich environments like forests.'
Dense forested environments today are home to some of the most heavily ornamented birds, like birds of paradise (Paradisaeidae).
Likewise, sexual selection has lead to a diversity of colourful and even iridescent tail plumes in modern birds, many of which are aerodynamically costly.
A possible reason for the extinction of enantiornithines along with the dinosaurs around 66 million years ago is that they were mostly forest dwellers.

Dense forested environments today are home to some of the most heavily ornamented birds, like birds of paradise (Paradisaeidae). Pictured, cicinnurus regius, a bird of paradise
Many experts believe the meteor strike that ended the dinosaurs' reign sparked a global fire storm that destroyed much of the world's forests.
The discovery of Y. kompsosoura could help answer questions about the birds that survived the big extinction event.
'Understanding why living birds are the most successful group of vertebrates on land today is an extremely important evolutionary question,' said O'Connor.
'Whatever it was that allowed them to be so successful probably also allowed them to survive a giant meteor hitting the planet when all other birds and dinosaurs went extinct.'
The study has been published in the journal Current Biology.
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