Lysorophia

Lysorophia are an order of aquatic Carboniferous and Permian amphibians, which resembled small snakes.

The skull is lightly built and open, with large orbits and fenestrae. The intertemporal, supratemporal, postfrontal, and jugal bones of the skull have disappeared. The mandibles are short, and the maxilla and premaxilla freely movable.

The torso is very elongate, the limbs diminutive or absent, and the tail short. There are up to 99 pre-sacral (i.e. not including the hips and tail) vertebrae.

Based on morphology of the cranio-vertebral articulation, Lysorophids are usually related to the Microsauria, although the pattern of bones of the skull is very different.

There is a single family, the Lysorophidae. The group is known mainly from the Late Pennsylvanian and Early Permian of North America.