Fossil of an Archaeopteryx found near Workerszell, Germany, in 1951 Photograph: Sally A. Morgan/Corbis

The Natural History Museum's original Archaeopteryx skeleton is known as the "London specimen", and a replica is on public display there.

In all, 10 Archaeopteryx skeletons have been discovered, all in quarries in Bavaria, south-east Germany, within a radius of about 15 miles. The fossils were buried in very fine-grained limestone near the village of Solnhofen (during the Jurassic period, this part of Germany was covered by a warm, shallow lagoon with a soft mud bottom that has proved ideal for preserving ancient fossils).

While nothing like Archaeopteryx has been discovered anywhere else in the world, it is clear there must have been a line of earlier "protobirds" from which it evolved - these just haven't been found yet.

Archaeopteryx was small, growing up to half a metre long (and half of that was tail). It shared key skeletal features with small, carnivorous theropod dinosaurs such as Deinonychus and Velociraptor. But in addition to carefully preserving these ancient fossils, the limestone also revealed a clear impression of Archaeopteryx's flight and contour wing feathers (the actual feathers had disintegrated long ago). The structure of these feathers was almost exactly like those found on birds today, leading scientists to infer that Archaeopteryx must have had some ability to fly.

Much more recently, use of modern CT ("computed tomography") scanning equipment on the London Archaeopteryx's skull has enabled scientists to reconstruct the whole of its bony brain case - and so model the structure of the brain itself. The research showed that Archaeopteryx's brain was built and organised like a modern bird's brain - a fundamental evolutionary shift away from dinosaurs.