Rhineuridae – North American worm lizards

Rhineuridae, often referred to as the North American worm lizards, represents a family of amphisbaenians that is quite unique both in appearance and lifestyle. This family currently includes only one living species, the Florida worm lizard. This singular survivor provides a fascinating glimpse into the adaptive traits of a group that has existed since prehistoric times, showing minimal evolutionary changes over millions of years.

Physically, the Florida worm lizard is quite distinct from typical lizards. It has a long, slender, and cylindrical body that resembles a worm, aiding in its burrowing lifestyle. It measures about 25 to 30 cm (10 to 12 in) in length and is characterized by a pinkish-brown skin that lacks scales, instead covered by a smooth, shiny surface that facilitates movement underground. Its head is small and pointed, designed to push through soil and leaf litter, and its eyes are reduced to tiny, light-sensing spots covered by skin, reflecting its subterranean habitat where vision is unnecessary.

One of the most remarkable aspects of Rhineuridae is their highly specialized mode of life. They are fossorial, meaning they are adapted to digging and life underground. Their body movements are similar to those of earthworms, using contractions to propel themselves forward in their subterranean tunnels. This lifestyle makes them elusive and difficult to study, as they spend almost all their time beneath the surface.

The diet of the Florida worm lizard mainly consists of small invertebrates, such as ants and termites, which they find in their underground environment. Their presence in the ecosystem is beneficial as they help control pest populations, contributing to the ecological balance of their habitat.