Professor Barry Cox is head of the biology department at Kings College, University of London. His specialty is mammal like reptiles, and he teaches vertebrate paleontology. His publications include Prehistoric Life Explained.Professor R. J. G. Savage is head of the geology department at the University of Bristol. Author of several books, including Mammal Evolution, he is among the worlds foremost experts on mammal fossils.Professor Brian Gardiner teaches vertebrate paleontology at Kings College, University of London. He is an expert on fossil fishes and amphibians, and advisor on paleontology to the Natural History Museum in London.Dr. Colin Harrison, an expert on bird zoology and paleontology, is the former principal scientific officer of ornithology at the British Museum (Natural History) in London.