You are about to embark upon Expedition: Fossils, a tour through the evolution of vertebrates. Using the expedition guide in the frame at your left, you can follow the family tree of vertebrates. Each branching point, or node, on the tree represents the evolution of a new physical characteristic. From each of these nodes you can examine fossil specimens representing these features.

This cladogram depicts the over-arching structure through which your expedition will proceed. As you visit each node you will see cladograms that show further detail.