Cycloneritida (nerites and false-limpets) is an order of

land snail A land snail is any of the numerous species of snail that live on land, as opposed to the sea snails and freshwater snails. ''Land snail'' is the common name for terrestrial gastropod mollusks that have shells (those without shells are known as ...

s, freshwater snails, and sea snails.MolluscaBase eds. (2020). MolluscaBase. Cycloneritida. Accessed through: World Register of Marine Species at: http://www.marinespecies.org/aphia.php?p=taxdetails&id=1054475 on 2020-08-21 These are

gastropod The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, from freshwater, and from land. T ...

mollusc Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is esti ...

s within the subclass Neritimorpha. 14 of the families in the order are extant, and eight of the families are extinct. It was previously categorized as the

clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...

Cycloneritimorpha. According to the Taxonomy of the Gastropoda (Bouchet & Rocroi, 2005), as well as the Cycloneritida, the subclass Neritimorpha also contains the (entirely fossil) clade

Cyrtoneritimorpha Cyrtoneritimorpha, also Cyrtoneritida, is a clade of fossil sea snails, marine gastropod mollusks within the clade Neritimorpha Neritimorpha is a taxonomic grouping, an unranked major clade of snails, gastropod mollusks. This grouping ...

, plus a number of other fossil families that are currently unassigned. The earliest evolutionary forms of Cycloneritimorpha show double visceral organs, double gills, and normally a double-chambered heart.

Taxonomy

The taxonomy of Cycloneritida is based on work by Kano et al. (2002) that recognizes 4 clades. These clades are established on genetic analysis (

28S rRNA Crazy Eights is a shedding-type card game for two to seven players and the best known American member of the Eights Group which also includes Pig and Spoons. The object of the game is to be the first player to discard all of their cards. The ga ...

) of recent species only. These clades proposed by Kano are ranked as superfamilies in the taxonomy of the Gastropoda (Bouchet & Rocroi, 2005). The spelling of Cycloneritimorpha has been amended to the order Cycloneritida in the new taxonomy of the Gastropoda by Bouchet and Rocroi in 2017 Philippe Bouchet & Jean-Pierre Rocroi, Revised Classification, Nomenclator and Typification of Gastropod and Monoplacophoran Families; Malacologia, 2017, 61(1–2): 1–526 Clade Cycloneritimorpha contains: *Superfamily

Helicinoidea Helicinoidea is a taxonomic superfamily of land snails that have an operculum. In other words, they are terrestrial operculate gastropod mollusks. They are in the superfamily Neritoidea and are quite closely related to the marine and freshwate ...

**Family Helicinidae ** † Family

Dawsonellidae ''Dawsonellidae'' is an extinct taxonomic family of fossil sea snails, marine, gastropod mollusk Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks ...

** † Family

Deaniridae ''Deianiridae'' is an extinct taxonomic family of fossil sea snails, marine gastropod mollusk Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). ...

**Family

Neritiliidae Neritiliidae is a family of submarine cave snails,Kano Y. & Kase T. (2008). "Diversity and distributions of the submarine-cave Neritiliidae in the Indo-Pacific (Gastropoda: Neritimorpha)". ''Organisms Diversity & Evolution'' 8(1): 22-43. marine ...

**Family

Proserpinellidae Proserpinellidae is a Taxonomy (biology), taxonomic family (biology), family of land snails with an operculum (gastropod), operculum, terrestrial animal, terrestrial gastropod mollusks in the superfamily Helicinoidea (according to the Taxonomy o ...

**Family Proserpinidae *Superfamily Hydrocenoidea **Family

Hydrocenidae Hydrocenidae is a taxonomic family of minute land snails or cave snails with an operculum, terrestrial gastropod mollusks or micromollusks in the clade Cycloneritimorpha. Hydrocenidae are widespread across the Palearctis and Africa, but re ...

* † Superfamily Naticopsoidea Waagen, 1880 *Superfamily

Neritoidea Neritoidea is a taxonomic superfamily of mostly sea snails, nerites and their allies, marine gastropod mollusks in the order Cycloneritida (according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005). MolluscaBase eds. (2020). Mollus ...

**Family Neritidae **Family

Phenacolepadidae Phenacolepadidae is a family (biology), family of small sea snails or false limpets, marine (ocean), marine gastropod mollusks in the clade Cycloneritimorpha (according to the Taxonomy of the Gastropoda (Bouchet & Rocroi, 2005), taxonomy of the G ...

** † Family

Pileolidae ''Pileolidae'' is an extinct family of fossil sea snails, marine gastropod mollusks. This family is related to the extant family Neritidae, the nerites. The family has no subfamilies according to the taxonomy of the Gastropoda by Bouchet & Ro ...

*Superfamily Neritopsoidea **Family

Neritopsidae Neritopsidae is a family of small sea snails and freshwater snails in the clade Cycloneritimorpha (according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005). The great majority of species within this family are only known as fossil ...

** † Family

Cortinellidae ''Cortinellidae'' is an extinct taxonomic family of fossil sea snail Sea snail is a common name for slow-moving marine gastropod molluscs, usually with visible external shells, such as whelk or abalone. They share the taxonomic class Gast ...

** † Family

Delphinulopsidae ''Delphinulopsidae'' is an extinct taxonomic family of fossil sea snails, marine, gastropod mollusks. Taxonomy According to taxonomy of the Gastropoda by Bouchet & Rocroi (2005) the family Delphinulopsidae has no subfamilies. 2007 taxono ...

** † Family Plagiothyridae ** † Family

Pseudorthonychiidae Pseudorthonychiidae is an extinct, monogeneric (contains only one genus) family of fossil snails, gastropod mollusks in the clade Cycloneritimorpha Cycloneritida (nerites and false-limpets) is an order of land snails, freshwater snails, a ...

**Family Titiscaniidae * † Superfamily

Symmetrocapuloidea Symmetrocapulidae is an extinct taxonomic family of fossil snails, gastropod mollusks in the monotypic superfamily Symmetrocapuloidea within the clade Cycloneritimorpha Cycloneritida (nerites and false-limpets) is an order of land snails ...

** † Family

Symmetrocapulidae Symmetrocapulidae is an extinct taxonomic family of fossil snails, gastropod mollusks in the monotypic superfamily Symmetrocapuloidea within the clade Cycloneritimorpha Cycloneritida (nerites and false-limpets) is an order of land snails ...

References

{{Taxonbar, from1=Q88577371, from2=Q2443153 Gastropod taxonomy