Opisthoglyphous

A snake skeleton consists primarily of the skull, vertebrae, and ribs, with only vestigial remnants of the limbs.

The skull of a snake is a very complex structure, with numerous joints to allow the snake to swallow prey far larger than its head.

The typical snake skull has a solidly ossified braincase, with the separate frontal bones and the united parietal bones extending downward to the basisphenoid, which is large and extends forward into a rostrum extending to the ethmoidal region. The nose is less ossified, and the paired nasal bones are often attached only at their base. The occipital condyle is either trilobate and formed by the basioccipital and the exoccipitals, or a simple knob formed by the basioccipital; the supraoccipital is excluded from the foramen magnum. The basioccipital may bear a strong, curved ventral process or hypapophysis in the vipers.

The prefrontal bone is situated, on each side, between the frontal bone and the maxilla, and may or may not be in contact with the nasal bone.

The postfrontal bone, usually present, borders the orbit behind, rarely also above, and in the pythons a supraorbital bone is between it and the prefrontal bone.