Chelicerates are a group of arthropods distinguished by the following characters:

• a body divided into a cephalothorax and abdomen

• no antennae, but two pairs of appendages on the anterior cephalothorax (chelicerae and pedipalps), and four pairs of walking legs

Examples of chelicerates include spiders, scorpions, and horseshoe crabs.

Black Widow Spider photo by George W. Robinson © California Academy of Sciences; Scorpion photo by Dr. Antonio J. Ferreira © California Academy of Sciences; Horseshoe Crab photo © 2000 John White