Evolutionary Biology of Primitive Fishes

What, precisely, is a primitive fish? Most biologists would agree that the living cyclostomes, selachians, crossopterygians, etc. cannot be considered truly primitive. However, they and the fossil record have served to provide the information which forms the basis for speculation concerning the nature of the original vertebrates. This symposium of biologists from a variety of disciplines was called together to create collectively, from the best available current evidence, a picture of the p...