Millerelix simpsoni like many other organisms in the world, are complex. Scientists are able to better understand each organism by looking at a phylogenetic tree (Gillis, 2012). Classification in the simplest form consists of a domain, kingdom, phylum, class, order, family, genus, and species classification (Gillis, 2012). Although most phylogenic trees are more complicated because they can have groups within each grouping. Continuing on, an organism will be placed onto a specific domain, kingdom, phylum, class, order, family, genus or species if it has a homologous characteristic of the said group (Gillis, 2012). A homologous characteristic is a physical characteristic that has the same common ancestor (Gillis, 2012). In other words, the organism in a specific group came from an ancestor and all the organisms in that group also had the same ancestor (Gillis, 2012). Phylogenetic trees are like pyramids. In general, the pyramid starts off large with millions of diverse organisms. This is called the domain classification. Then as the organism moves towards the top, the organisms become more similar until finally they are all the same.

As for Millerelix simpsoni, it is first seen in the domain Eukarya. It is seen in this group because it is a eukaryote cell. Eukaryote cells have organelles such as: the cell membrane, cytoplasm, nucleus, golgi apparatus, mitochondria, rough endoplasmic reticulum and smooth endoplasmic reticulum (San Dieco State University. 2012).

Following the domain, this species is next found in the kingdom, Animalia. Animalia characteristics are multi-cellular and heterotrophs (Animal Diversity Web, 2012). Heterotrophs cannot get their energy from sunlight and must receive their energy from other organisms (Hickman et al. 2012). In addition, these organisms have tissues, no cell walls, and they can digest their food (Animal Diversity Web 2012).

Moving up in the pyramid is a phylum. Millerelix simpsoni is found in phylum Mollusca. Mollusca have a head, visceral mass and a foot (Gillis, 2012). Visceral mass in a snail is essentially the body of the snail that contains all of its internal organs (Hickman et al. 2012). The foot is primarily used for locomotion and capturing food (Gillis, 2012). To enclose the various organs, molluscs have a mantle (Gillis, 2012). In addition, this phylum also developed a radula (Gillis, 2012). A radula is an organ that is used to remove the outer portion of the snail’s food, which can also be learned about on the nutrition page (Gillis, 2012).   

Next grouping category is called a class, in which it is found in class Gastropoda. All gastropods have a shell that is highly coiled, a soft body, a foot, torsion, one to two tentacles, and eyes (Leonard, 1959). Torsion occurs when the visceral mass becomes twisted during the snail development (Gillis, 2012). Additionally, gastropods can be monoecious (contains both female and male sex organs) or dioecious (either female or male sex organs) (Hickman et al. 2012). Millerelix simpsoni are monoecious (Thorp and Covich, 2010).

Continuing onto the order, Millerelix simpsoni is classified in the order Pulmonata. Organisms in this order include both terrestrial and aquatic snails and even some slugs (Hickman et al. 2012). A key physical characteristic for this group is that most organisms have developed a lung used breathing air (Hickman et al. 1959). Additionally within the order Pulmonata there are two suborders: Basommatophora and Stylommatophora (Hickman et al. 1959). Millerelix simpsoni is in the suborder, Stylommatophora because its eyes are located on top of its tentacles (Leonard, 1959). In contrast, organisms in the Basommatophora have eyes on the bottom or base of its tentacles (Leonard, 1959).

The next group that adds more specific characteristics about Millerelix simpsoni is a family. This snail’s family is the Polygyridae (Leonard, 1959). Polygyrids have shells that appear to be lens shaped and the opening of the snail’s shell is a dull, white, glossy color (Leonard, 1959). Lastly, the snail can be further placed into its genus named Millerelix. In this genus, organisms will have an umbilicus (Leonard, 1959).