Evolution of Fish
Evolution of Fish





    The coelacanth is a lobe-finned fish and it evolved from the armoured fish (BBC, 1998). Fish are chordates like humans, meaning they have a notochord, or spine (Parrish, 1998). The first fish to evolve were the Agnathans, which were armoured, jawless fish the lived in the Devonian and Silurian periods (Parrish, 1998). They first appeared 510 million years ago (Parrish, 1998). Next the Acanthodians appeared in the middle Silurian, and they were also armoured fish, but they had jaws (BBC, 1998). The Placoderms appeared next in the middle to late Silurian and they had jaws and platey scales (BBC, 1998). The lobe-finned and lungfish both appeared about the same time in the middle Devonian.