The locating of the hyoid bone in anatomy atlases and textbooks may be misleading, as it is usually reviewed together with the bones of the skull. The reason for that lies in the legacy anatomy nomenclature preserved up to the end of the XX century1, allocating hyoid bone as part of the viscerocranium. Strictly speaking, the hyoid bone is not the structural part of the skull but rather is an integral part of the larynx (just like sesamoid bones are an integral part of the muscle's tendon). However, the most recent anatomical terminology review2 allocates the hyoid bone and mandible separately from the skull's bones in the chapter defined as "the extracranial bones of the head."
1 Federative Committee on Anatomical Terminology. Terminologia Anatomica. Thieme; 1998.