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.
Pteraspidomorphi, Palaeos. Descriptions and pictures of Ordovician armored fish, which represent some of the earliest known fossil vertebrates (not including the recently found fossils from the Cambrian of Chengjiang, China). Descriptions and images are also provided of the Heterostraci, another group of ostracoderms from the Silurian and Devonian.
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.
Paleozoic Fossils UK. Pictures of fossils from the Paleozoic Era of Britain.
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