Evolving from biplanes to monoplane dinosaurs

The dinosaur had two sets of feathered wings, on its forelimbs and hind legs and is believed to have "flown" like a flying squirrel - gliding, but incapable of true flight.

The Chinese scientists who found the Microraptor fossil proposed that when it glided between trees, it spread out its legs and kept its wings one behind the other in a tandem pattern similar to a dragonfly.

But using computer models and anatomical analysis, Sankar Chatterjee, a paleontologist at Texas Tech University, and Jack Templin, an aeronautical engineer, decided that such an arrangement could not have worked.

Chatterjee proposed that Microraptor positioned its hind legs below its body, adopting a "biplane" arrangement.

He said: "We knew that there was something wrong anatomically. There is just one choice. It has to have this biplane wing design."

A computer flight simulation of Microraptor employing this wing arrangement demonstrated it would undulate up and down, necessary for gliding among trees, and may have been able to glide over a distance of 40 metres.