In the mid 1800s, when Charles Darwin published his theory of evolution, one species of animal remained a mystery; where did birds fit on his evolutionary tree? Several years later his friend and colleague, Thomas Henry Huxley, came up with an answer. Huxley had recently examined a new fossil from southern Germany called Archaeopteryx which was causing considerable excitement in palaeontological circles. There were clear signs of feathers and it was obvious this was the earliest fossil evidence of a bird ever found. Huxley noticed something else as well. To him it looked as though the skeleton bore a striking similarity to that of a family of meat eating dinosaurs known as therapods. In the 1860s, on the basis of this observation, he announced a new theory; birds must have evolved from dinosaurs. The theory ignited what was to become one of the biggest controversies in palaeontology. Could Huxley possibly be right; how could a large, land-bound creature like a dinosaur have ever evo