The occipital bone /əkˈsɪpɨtəl/, a saucer-shaped membrane bone situated at the back and lower part of the cranium, is trapezoidal in shape and curved on itself. It is pierced by a large oval aperture, the foramen magnum, through which the cranial cavity communicates with the vertebral canal.
The curved, expanded plate behind the foramen magnum is named the squama occipitalis. The thick, somewhat quadrilateral piece in front of the foramen is called the basilar part of occipital bone.
On either side of the foramen are the lateral parts of occipital bone.