Microraptor, the four-winged dinosaur

Microraptor gui, described by Xu Xing and colleagues in 2003 from the Jiufotang Formation of Liaoning, was a dromaeosaur, a relative of Velociraptor, about 80 cm long and around 1 kg. Its arms carried long flight feathers, and so did its hind legs, giving it four wings. Its tail ended with a fan of long feathers. Later work by Quanguo Li and colleagues in 2012 showed from pigment bodies that its plumage was glossy black, with an iridescent sheen like a crow's.

How Microraptor moved is debated: wind tunnel models and fossils suggest it could glide from tree to tree, and many researchers think it could also flap in powered flight. Stomach contents show that it ate fish, small birds and mammals, so it was an opportunist that lived in the trees and near water. The animal showed that flight was tried by several lineages of feathered dinosaurs, not only the one that led to birds.