Microraptor

Microraptor zhaoianus ("Zhao Xijin's small thief') is a small, feathered dromaeosaurid dinosaur species from the Lower Cretaceous (Middle Barremian-Lower Aptian). Like Archaeopteryx, it demonstrates the close evolutionary relationship between birds and dinosaurs, as it had long feathers on its limbs and tail. Two species have been named, M. zhaoianus and M. gui. It has recently been suggested that all of the specimens belong to a single species, which is properly called M. zhaoianus.

Technically, according to the rules of the International Code of Zoological Nomenclature, it should be referred to as Archaeoraptor liaoningensis. This is because the type specimen is actually the hindpart of the Archaeoraptor fraud slab. Archaeoraptor liaoningensis was the name Storrs L. Orson first gave to the hindpart (in a inconspicuous obscure journal), while the name Microraptor zhaoianus was given later, in 2000. The front half of that specimen is an avialan.

Microraptor was about 77cm long from its nose to the tip of its tail. Like its close relative Cryptovolans (possibly a junior synonym of Microraptor), Microraptor had long feathers on both its 'arms' and its 'legs', which has led to it being called a 'four-winged dinosaur'.

It has been proposed by Chinese scientists that the animal glided, rather than flew properly. However, close studies of the Berlin specimen of the primitive bird Archaeopteryx show that it too, had flight feathers on its hind legs, albeit shortened. Many scientists now think that all basal avians had feathers on their hind legs, and that they were used like the tail feathers of present birds for maintaining balance and changing direction in the air.

Six virtually complete skeletons have later been found in Liaoning, China. They were discovered in 2001 and 2002.