Chelicerae

The chelicerae (/kəˈlɪsəriː/) are the mouthparts of the subphylum Chelicerata, an arthropod group that includes arachnids, horseshoe crabs, and sea spiders. Commonly referred to as "jaws", chelicerae may be shaped as either articulated fangs, or as a type of pincers. Some chelicerae, such as those found on nearly all spiders, are hollow and contain (or are connected to) venom glands, used to inject venom into prey or a perceived threat. Both pseudoscorpions and harvestmen have additional structures on their chelicerae that are used for grooming (papillae in pseudoscorpions, cheliceral teeth in Opiliones).^[1] In Paratrechalea, males and females have shown to have a chelicerae dimorphism, because the chelicerae is used as a mating signal for females.