Chelicerata

Pterygotus swimming in prehistoric waters

Eurypterus, a fossil eurypterid

Mesolimulus, a fossil horseshoe crab

Limulus polyphemus, horsehoe crab

Naraoia compacta, trilobite

Fossilised Mesolimulus

Pterygotus anglicus, giant water scorpion

Limulus polyphemus, horseshoe crab

Eurypterius lacustris, sea scorpion