#class_Merostomata__Merostomata  used in some classifications; includes the orders Xiphosura and Eurypterida
  supertype:  #arthropod  invertebrate having jointed limbs and a segmented body with an exoskeleton made of chitin
  member of:  #superclass_Chelicerata
  member:  #order_Xiphosura__Xiphosura  horseshoe crabs and extinct forms
     member:  #family_Limulidae__Limulidae  horseshoe crabs
        member:  #genus_Limulus__Limulus  type genus of the family Limulidae
           member:  #horseshoe_crab__horseshoecrab__king_crab__Limulus_polyphemus__Xiphosurus_polyphemus  large marine arthropod of the American Atlantic coast having a domed horseshoe-shaped carapace and stiff pointed tail; a living fossil related to the wood louse
        member:  #genus_Tachypleus__Tachypleus  a genus of Limulidae
           member:  #Asian_horseshoe_crab  horseshoe crab of the coast of eastern Asia
  member:  #order_Eurypterida__Eurypterida  extinct aquatic arthropods of the Paleozoic
     member:  #eurypterid  large extinct scorpion-like arthropod considered related to horseshoe crabs

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