Jaekelopterus

phylum	Arthropoda	Fossils of Jaekelopterus have been discovered in deposits of Early Devonian age, from the Pragian and Emsian stages. There are two known species: the type species J. rhenaniae from brackish to fresh water strata in the Rhineland, and J. howelli from estuarine strata in Wyoming. J. rhenaniae has been estimated to have reached a size of around 2.3–2.6 metres (7.5–8.5 ft), making it the largest arthropod ever discovered, J. howelli was much smaller, reaching 80 centimetres (2.6 ft) in length. For more information, visit the Wikipedia entry. Get back to Eurypterid
class	Merostomata
order	Eurypterida
family	Pterygotidae
genus	Jaekelopterus