Horseshoe Crab and Decapod Orders

Horseshoe Crab and Decapod Orders is a Browse By group of the Nature Atlas that gathers the orders of two arthropod lineages, the horseshoe crabs of the order Xiphosura, whose few living species are chelicerates with a long sword-like tail spine, and the decapods of the order Decapoda, the crustaceans with ten walking legs that include crabs, lobsters and shrimp. An entry belongs here when its own cited article describes the order of horseshoe crabs or the order of decapod crustaceans. It excludes the arachnid orders, the cephalopod orders and the tusk shell orders, which have groups of their own. The group lets a reader compare an ancient chelicerate order with the largest order of crustaceans.