How does the worm snake's rigid skull contrast with the typical skull structure of many other modern snakes?

It lacks the kinetic motion necessary for swallowing large prey items

A defining characteristic separating the worm snake from many of its larger, surface-dwelling relatives is the rigidity of its skull structure. Many typical snakes possess a kinetic skull, meaning the bones of the upper and lower jaws are connected loosely, allowing for remarkable mobility and stretching required to swallow prey items much larger than their own heads. In contrast, the worm snake has evolved an incredibly rigid skull. This specific adaptation is directly linked to its exclusive diet of soft-bodied invertebrates; it does not require the wide gape mechanism necessary for engulfing large prey, instead relying on its bony, reinforced snout to push through soil.