The trail of the snail:SlugsClassification
Slugs,and also snails,belong to the group of animals called Mollusca.About 100.000 different species belong to this group,which have in common that they don't have backbones.The group is divided in seven classes, both slugs and snails belong to the class Gastropoda and the subclass Pulmonata. There are more than 30.000 different species of land slugs and land snails. This part of the doesn't cover the seaslugs,only the ones living on the land. You find slugs on more places than snails because they don't need calcium for their shells.Offcourse this makes them more vulnerable as well. Slugs have evolved from landsnails,some species still have a small extern shell, while others have only an internal one or some granules.Ofcourse there are some snailspecies who form an in between stage.(so called half slugs) Classification of slugs:
Class Pulmonata Order Styllomatophora Suborder Sigmurethra Infraorder Aulacopoda Superfamily Testacelloidea(?) Family Testacellidae Superfamily Arionacea Family Arionidae sub-family Anadininae sub-family Binneyinae sub-family Oopeltinae sub-family Ariolimacinae sub-family Arioninae Family Philomycidae Superfamily Limacoidea Family Boettgerillidae Family Limacidae Family Milacidae Family Parmacellidae family Trigonochlamydidae Infraorder Holopoda Superfamily Oleacinoidea Family Testacellidae Order Systellommatophora Superfamily Veronicellacea Family Veronicellidae Family Rathouisiidae