Which of the following is not a part of axial skeleton?

Axial skeleton consists of the skull (cranium and facial bones), sternum, vertebral column (sacrum is a part of vertebral column) and the rib cage. Ilium does not belong to axial skeleton.

Pelvic girdle consists of two coxal bones. Each coxal bone is formed by the fusion of three bones – ilium, ischium and pubis. The girdles along with the bones of limbs constitute the appendicular skeleton.