This class includes spiders, ticks, mites, scorpions, and their relatives.
Arachnids have four pairs of legs and no antennae or wings.
Despite its name, the horseshoe crab is not a crab, it is actually the only surviving relative of a chelicerate that lived long ago. The crab s closest relatives are scorpions and spiders. The horseshoe crabs body consists of two hinged parts. The prosoma and the abdomen. The prosoma is the part of the body enclosed in the shell and is where the head is.