Discus guerinianus is a species

Species

In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 of small air-breathing land snail

Land snail

A land snail is any of the many species of snail that live on land, as opposed to those that live in salt water and fresh water. Land snails are terrestrial gastropod mollusks that have shells, It is not always an easy matter to say which species are terrestrial, because some are more or less...

, a terrestrial

Terrestrial animal

Terrestrial animals are animals that live predominantly or entirely on land , as compared with aquatic animals, which live predominantly or entirely in the water , or amphibians, which rely on a combination of aquatic and terrestrial habitats...

 gastropod mollusk in the family Discidae

Discidae

Discidae is a taxonomic family of small air-breathing land snails, terrestrial gastropod mollusks in the superfamily Punctoidea.-Genera:The family Discidae has no subfamilies...

, the disk snails.

Distribution

This species is endemic to in Madeira, Portugal.

Shell description

The shell of these snails is shaped like a discus

Discus

Discus, "disk" in Latin, may refer to:* Discus , a progressive rock band from Indonesia* Discus , a fictional character from the Marvel Comics Universe and enemy of Luke Cage* Discus , a freshwater fish popular with aquarium keepers...

, or a lens

Lens (optics)

A lens is an optical device with perfect or approximate axial symmetry which transmits and refracts light, converging or diverging the beam. A simple lens consists of a single optical element...

, with a noticeable "edge" around the periphery of the whorl

Whorl (mollusc)

A whorl is a single, complete 360° revolution or turn in the spiral growth of a mollusc shell. A spiral configuration of the shell is found in of numerous gastropods, but it is also found in shelled cephalopods including Nautilus, Spirula and the large extinct subclass of cephalopods known as the...

s.

Conservation status

This species is mentioned in annexes IV and IV of the Habitats Directive.