What does cephalothoraces mean?
Cephalothoraces is the plural of cephalothorax, the compact anterior body region formed when an arthropod's head and thorax are fused. The term is especially associated with spiders, scorpions, and crustaceans, whose front body sections contain important sensory organs, mouthparts, and limbs. In a spider, the cephalothorax supports the eyes, chelicerae, pedipalps, and four pairs of legs. Calling it a cephalothorax rather than simply a head or chest emphasizes that these structures form a unified body region. Although the word is anatomically precise, it belongs mainly to zoological, paleontological, and technical writing rather than general conversation. Its unusual combination of Greek-derived elements makes it especially memorable: it is a name for the part of an animal that carries both its head and much of its apparent front end.
noun, pluralThe plural of cephalothorax: the fused head-and-thorax body region of an arthropod, especially a spider, scorpion, or crustacean.
- The plural form of cephalothorax, denoting the fused anterior body region of an arthropod.
"The scorpion's large pincers are attached to its cephalothoraces."
"A scorpion has two large pincers projecting from its cephalothoraces."
"The fossils preserve detached cephalothoraces and other fragments of the ancient arachnids."
This is the standard plural of the singular noun cephalothorax; the headword itself is already plural.
"The museum display includes the cephalothoraces of several preserved spiders."
A spider's cephalothorax is nature's head-and-shoulders merge: one compact body segment carrying its eyes, mouthparts, and all eight legs.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does cephalothoraces come from?
The singular cephalothorax was formed in New Latin from Greek kephalē, meaning “head,” and thōrax, meaning “breastplate” or “chest.” The compound refers to the fusion of these two body regions. In the English plural, the final /ks/ of the singular is retained and /ɪz/ is added. Related English words include cephalopod and encephalon, which share the head-forming Greek element, and thoracic, which derives from the same Greek source as thorax.
Related word forms
How cephalothoraces is actually used
A specialized zoological term used especially in arachnology, carcinology, and comparative anatomy. It is uncommon in ordinary speech.
Easily confused with cephalothoraces
Cephalothorax is the singular noun, while cephalothoraces is its standard plural form.
A thorax is the chest or thoracic body region alone, whereas a cephalothorax is a head and thorax fused into one region.