The cephalothorax is an anatomical term used of arachnid and malacostracan arthropods for the first major body section. It is derived from the fusion of the head (cephalon) and the trunk (thorax), and therefore includes all the mouthparts, antennae, and the thoracic appendages, such as the legs of a spider or lobster. The remainder of the body is the abdomen, which may also bear lateral appendages as well as the tail, if present. In the Malacostraca, the cephalothorax is typically covered by protective carapace.
