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Form can precede function, at least when it comes to mate-attracting feathers.

A part-bird, part-dinosaur described in the journal Nature this week didn’t have feathers for flying, but did possess ostentatious ornamental plumage, including four tailfeathers three times longer than its pigeon-sized body.

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Epidexipteryx (“display” + “wing, feather”) lived during the middle-to-late Jurassic, predating the famed Archaeoptryx, and represents an alternative evolutionary pathway from dinosaurs to birds.

The discovery by the Chinese Academy of Sciences adds complexity to the presumed road from T-rex to turkey vulture because the creature looks like a mythological chimera. And that, in the words of the authors of the paper, is “bizarre”.

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Similar in size and shape to a European Magpie, Archaeopteryx could grow to about 0.5 metres (1.6 ft) in length. Despite its small size, broad wings, and ability to fly, Archaeopteryx has more in common with small theropod dinosaurs than it does with modern birds. In particular, it shares the following features with the deinonychosaurs (dromaeosaurs and troodontids): jaws with sharp teeth, three fingers with claws, a long bony tail, hyperextensible second toes (“killing claw”), feathers (which also suggest homeothermy), and various skeletal features.

The features above make Archaeopteryx the first clear candidate for a transitional fossil between dinosaurs and birds. Thus, Archaeopteryx plays an important role not only in the study of the origin of birds but in the study of dinosaurs.

The first complete specimen of Archaeopteryx was announced in 1861, only two years after Charles Darwin published On the Origin of Species, and it became a key piece of evidence in the debate over evolution. Over the years, nine more fossils of Archaeopteryx have surfaced. Despite variation among these fossils, most experts regard all the remains that have been discovered as belonging to a single species, though this is still debated.

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