Classification

Domain: Eukarya: Cells posses nuclear envelope containing DNA
Kingdom: Animalia: Multi-celled, contains specialized tissues
Phylum: Mollusca: Bilateral symmetry, possesses both a mantle and a radula
Class: Gastropod: Body displays torsion, a single spiral shell
Order: Stylommatophora: Relatively long pedal gland, retractile tentacles (Dedov, 1998)
Family: Pupillidae: Pupilla muscorum has a small pupa-shaped shell (Animal Base, 2010)
Genus: Pupilla: lives in climates with a cooler tempurature. (Franzen, 1947)
Species: muscorum: Small, generally toothless (but may possess one or two) aperture. Palatal fold is small and tubercular in shells with teeth (Burch,1962)

The Problem of Pupilla pratensis

Pupilla pratensis, long considered to be a phenotypic variation of Pupilla muscorum, was determined to be a separate species in 2009 by a study of morphological, ecological and genetic observations. These observations were conducted by members of the Biology Dept. of the University of Bergen. Up to this point, Pupilla pratensis was classified as a mutation of Pupilla muscorum. (Proschwitz, et al. 2009) The two species live sympatrically, meaning they occupy much of the same geographical area, but do not reproduce together (Animal Base, 2010). Despite looking very similar, the two can be told apart by a close inspection of their appearance. Pupilla muscorum has a thicker-walled, more slender shaped shell and has lighter, more varied coloring.(Animal Base, 2010)