The [[coccyx]] (/ˈkɒksɪks/ kok-siks; plural: coccyges), commonly referred to as the tailbone, is the final segment of the vertebral column in humans and apes. Comprising three to five separate or fused coccygeal vertebrae below the [[sacrum]]. It is attached to the sacrum by a fibrocartilaginous joint, the [[sacrococcygeal symphysis]], which permits limited movement between the sacrum and the coccyx.