Key Earth Science Links
Early Paleozoic Rise of Fish
Arandaspida, Tree of Life Web Project. Descriptions of one of the most primitive groups of fishes. Examples of Ordovician fossils, phylogenetic relationships, physical characteristics, and references.
Introduction to the Placodermi, University of California, Berkeley. Short description of the earliest jawed fish, the placoderms.
Devonian Times, D.C. Murphy. This site provides information about fossil fish and other fossils found at the Devonian-age Red Hill site in Pennsylvania. Good "fact sheets" with graphs of fish evolution through time are provided for the primary Devonian fish lineages, including placoderms (armored, jawed fish), sharks and their kin, and lobe-finned fish.