How do limbless lizards move through sand and soil?

Limbless lizards move through sand and soil using specialized locomotor patterns that rely on their body shape and musculature rather than limbs.12

For movement through sand, some limbless lizards, such as the California legless lizard (Anniella), utilize a method described as "swimming" through the substrate. This is possible because friable sand is compact but lacks strong cohesiveness, allowing the animal to propel itself through the medium. These lizards typically rely on lateral undulations generated by complex ventral abdominal muscles to move quickly across the surface or through the sand.13

When burrowing through soil, these reptiles often employ axial locomotion, which can be categorized into three primary patterns:2
* Snout-driven: The snout is driven forward along the bottom of a tunnel, the head is raised, and the soil is compacted against the roof.2
* Lateral swinging: The snout is shoved forward and then swung from side to side.2
* Rotational: The snout is rotated as it swings from side to side, effectively shaving the walls of the tunnel.2

These burrowing lizards often possess smooth scales and reduced eyes, which facilitate movement through subterranean environments.4