bone is not easily susceptible to fracture. In a suspected case of murder or physical abuse of an adult, a fractured hyoid strongly indicates throttling or strangulation. In children and adolescents (in whom the hyoid bone is still flexible because ossification is yet to be completed) fracture may not occur even after serious trauma. Other animals The hyoid bone is derived from the lower half of the second gill arch in fish, which separates the first gill slit from the spiracle, and is often called the hyoid arch. In many vertebrates, it also incorporates elements of other gill arches, and has a correspondingly greater number of cornua. Amphibians and reptiles may have many cornua, while mammals (including humans) have two pairs, and birds only one. In birds, and some reptiles, the body of the hyoid is greatly extended forward, creating a solid bony support for the tongue. The howler monkey Alouatta has a pneumatized hyoid bone, one of the few cases of postcranial pneumatization of bones outside Saurischia. In woodpeckers the hyoid bone is elongated, with the horns wrapping around the back of the skull. This is part of the system that keeps the brain cushioned and undamaged by the pecking action. In mammals, the hyoid often determines whether one can roar. If the hyoid is incompletely ossified (for example: lions) it allows the animal to roar, but not purr. If the hyoid is completely ossified (for example: cheetahs), it does not allow the animal to roar, but instead will allow the animal to purr and meow, as seen in house cats (lions, cheetahs and house cats all belong to the family Felidae). In veterinary anatomy, the term hyoid apparatus is the collective term used to refer to the bones of the tongue—a pair of stylohyoidea, a pair of thyrohyoidea, and unpaired basihyoideum—and associated, upper-gular connective tissues. In humans, the single hyoid bone is an equivalent of the hyoid apparatus. See also Adam's apple References External links () Human head and neck Irregular bones