Pneumopulmonata is a

superorder Order () is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between family and class. In biological classification, the order is a taxonomic rank used in the classification of organisms and recognized ...

heterobranch Heterobranchia, the heterobranchs (meaning "different gill"), is a taxonomic clade of snails and slugs, which includes marine, aquatic, and terrestrial gastropod molluscs. Heterobranchia is one of the main clades of gastropods. Currently Hetero ...

pulmonate Pulmonata or pulmonates is an informal group (previously an order, and before that, a subclass) of snails and slugs characterized by the ability to breathe air, by virtue of having a pallial lung instead of a gill, or gills. The group inclu ...

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

belonging to the subterclass

Tectipleura Tectipleura is a subterclass of land and water-dwelling gastropods. The group consists of over 27,000 various species, among which are various groups of snails, slugs, and sea hares living across various diverse habitats around the world. It un ...

. It was defined based on results of

phylogenomic Phylogenomics is the intersection of the fields of evolution and genomics. The term has been used in multiple ways to refer to analysis that involves genome data and evolutionary reconstructions. It is a group of techniques within the larger fields ...

studies and named by Krug et al. (2022). The superorder unites all of

Panpulmonata Panpulmonata is a taxonomic clade of snails and slugs in the clade Heterobranchia within the clade Euthyneura. Panpulmonata was established as a new taxon by Jörger et al. in October 2010. The older name "Pulmonata" referred to a group of euth ...

except for

Sacoglossa Sacoglossa are a superorder of small sea slugs and sea snails, marine gastropod mollusks that belong to the clade Heterobranchia known as sacoglossans. There are 284 valid species recognized within this superorder. Sacoglossans live by ingestin ...

Description

Synapomorphy In phylogenetics, an apomorphy (or derived trait) is a novel Phenotypic trait, character or character state that has evolution, evolved from its ancestral form (or Plesiomorphy and symplesiomorphy, plesiomorphy). A synapomorphy is an apomorphy sh ...

of the group is the presence of a

pneumostome The pneumostome or breathing pore is a respiratory opening of the external body anatomy of a pulmonate land slug or land snail. It is a part of the respiratory system of gastropods. It is an opening in the right side of the mantle of a st ...

. It as established for the taxa comprising all descendants of the last common ancestor shared by

Siphonarioidea Siphonarioidea is a taxonomic superfamily of air-breathing sea snails or false limpets, marine gastropod mollusks in the clade Panpulmonata. Distribution The Siphonarioidea are broadly distributed across the globe, however they are known to ...

Amphiboloidea Amphiboloidea is a taxonomic superfamily of air-breathing land snails. Distribution Amphibolids are found in Indo-Pacific intertidal mangrove, saltmarsh and estuarine mudflat habitats. Taxonomy 2005 taxonomy According to the taxonomy o ...

and

Stylommatophora Stylommatophora is an orderPhilippe Bouchet, Jean-Pierre Rocroi, Bernhard Hausdorf, Andrzej Kaim, Yasunori Kano, Alexander Nützel, Pavel Parkhaev, Michael Schrödl and Ellen E. Strong. 2017. Revised Classification, Nomenclator and Typification of ...

. MolluscaBase eds. (2024). MolluscaBase. Pneumopulmonata. Accessed through: World Register of Marine Species at: https://www.marinespecies.org/aphia.php?p=taxdetails&id=1586068 on 2024-10-26 It mainly contains clades occurring at the interface between sea and land, in freshwater, and in terrestrial habitats. The following groups are included: *

Acochlidiacea Acochlidiacea, common name acochlidians, are a Taxonomy (biology), taxonomic clade of very unusual sea snails and sea and freshwater slugs, aquatic animal, aquatic gastropod mollusks within the large clade Heterobranchia. Acochlidia is a variant ...

* Pylopulmonata **

Pyramidelloidea Pyramidelloidea is a superfamily of mostly very small sea snails, marine gastropod mollusks and micromollusks within the clade Panpulmonata. This is a voluminous taxon: above the species level close to 400 named taxa are referred to this gastr ...

Glacidorboidea The Glacidorbidae is a Taxonomy (biology), taxonomic family (biology), family of freshwater snails. Taxonomy 2005 taxonomy Glacidorbidae is the only family in the superfamily Glacidorboidea. Glacidorboidea has been classified within the info ...

* Hygrophila *

Eupulmonata Eupulmonata is a taxonomic clade of air-breathing gastropod molluscs. The great majority of this group are land snails and slugs, but some are intertidal or inhabit coastal saltmarshes and mangroves. Possible synapomorphy of the group are gl ...

** Ellobiida **

Systellommatophora The Systellommatophora (synonym Gymnomorpha) is a clade of primitive, air-breathing slugs, according to the taxonomy of the Gastropoda (Bouchet & Rocroi, 2005). They are marine and terrestrial pulmonate gastropods within the Heterobranchia. T ...

The clade largely overlaps with the former

Pulmonata Pulmonata or pulmonates is an informal group (previously an order, and before that, a subclass) of snails and slugs characterized by the ability to breathe air, by virtue of having a pallial lung instead of a gill, or gills. The group includes ...

, but includes additional lineages as Pyramidelloidea. It is a sister group of

within

. Repeated colonizations of the freshwater and terrestrial realms occurred in this clade, and the biology and anatomy of its members is important for understanding the

evolution Evolution is the change in the heritable Phenotypic trait, characteristics of biological populations over successive generations. It occurs when evolutionary processes such as natural selection and genetic drift act on genetic variation, re ...

of the highly diverse stylommatophoran land snails. The individual subgroups differ in the digree of their terrestrialization as well as in the anatomical similarity to stylommatohora, sometimes reversing evolutionary trends seen in related groups: * Siphonarioidea include a single

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

of marine

limpet Limpets are a group of aquatic snails with a conical gastropod shell, shell shape (patelliform) and a strong, muscular foot. This general category of conical shell is known as "patelliform" (dish-shaped). Existing within the class Gastropoda, ...

-like

intertidal The intertidal zone or foreshore is the area above water level at low tide and underwater at high tide; in other words, it is the part of the littoral zone within the tidal range. This area can include several types of habitats with various sp ...

(but see the

subtidal The neritic zone (or sublittoral zone) is the relatively shallow part of the ocean above the drop-off of the continental shelf, approximately in depth. From the point of view of marine biology it forms a relatively stable and well-illuminate ...

'' Williamia'') gastropods. They have a large

pallial cavity The mantle (also known by the Latin word pallium meaning mantle, robe or cloak, adjective pallial) is a significant part of the anatomy of molluscs: it is the dorsal body wall which covers the visceral mass and usually protrudes in the form of ...

containing a secondary

gill A gill () is a respiration organ, respiratory organ that many aquatic ecosystem, aquatic organisms use to extract dissolved oxygen from water and to excrete carbon dioxide. The gills of some species, such as hermit crabs, have adapted to allow r ...

on a large part of its roof and opening by a non-contractible pneumostome on the right side of the body. During the high tide the cavity fills with water, at low tide it is used a lung. The pneumostome lacks a

sphincter A sphincter is a circular muscle that normally maintains constriction of a natural body passage or orifice and relaxes as required by normal physiological functioning. Sphincters are found in many animals. There are over 60 types in the human bo ...

Anus In mammals, invertebrates and most fish, the anus (: anuses or ani; from Latin, 'ring' or 'circle') is the external body orifice at the ''exit'' end of the digestive tract (bowel), i.e. the opposite end from the mouth. Its function is to facil ...

is located at the pneumostome. There is no operculum,

tentacles In zoology, a tentacle is a flexible, mobile, and elongated organ present in some species of animals, most of them invertebrates. In animal anatomy, tentacles usually occur in one or more pairs. Anatomically, the tentacles of animals work main ...

are absent.

Radula The radula (; : radulae or radulas) is an anatomical structure used by mollusks for feeding, sometimes compared to a tongue. It is a minutely toothed, chitinous ribbon, which is typically used for scraping or cutting food before the food enters ...

has many small and rather uniform teeth in each row. The genital system has a common spermoviduct ending in a copulatory organ and a single genital opening. Sperm is transferred in a

spermatophore A spermatophore, from Ancient Greek σπέρμα (''spérma''), meaning "seed", and -φόρος (''-phóros''), meaning "bearing", or sperm ampulla is a capsule or mass containing spermatozoa created by males of various animal species, especiall ...

. Development is through a free-swimming

veliger A veliger is the planktonic larva of many kinds of sea snails and freshwater snails, as well as most bivalve molluscs (clams) and tusk shells. Description The veliger is the characteristic larva of the gastropod, bivalve and scaphopod taxono ...

larva. * Acochlidiacea is a group of shell-less gastropods of tiny size, mostly with distinctive dorsal visceral hump. They are mostly marine, inhabiting the interstitial of coastal sands, but there are also freshwater species. Pallial cavity is small or missing. Anus is located on the right side, may be moved to the visceral hump in some species. Operculum is missing. Two pairs of tentacles (rhinophores and labial tentacles) are present, but do not bear eyes. Radula is narrow, with as few as just one tooth per row, in some species asymmetric. Some are secondarily

gonochoric In biology, gonochorism is a sexual system where there are two sexes and each individual organism is either male or female. The term gonochorism is usually applied in animal species, the vast majority of which are gonochoric. Gonochorism contrast ...

, otherwise there is a common spemoviduct either ending with a single opening, connected to a copulatory organ/penial sheath by an external groove, or there is vas deferens and a separate male opening. At least some species use spermatophores for sperm transfer. Some species have veliger larvae. * Amphiboloidea occur in on intertidal mud flats in marine or brackish water and are active during the low tide. The pallial cavity is used for breathing air when the snail is exposed, but also for breathing in water. There is no contractile pneumostome. Operculum is developed. The is one pair of tentacles, eyes are located near their base. Radula has many similar teeth per row. The structure of the genital system varies: there is a single genital opening, but there may be a common spermoviduct ('' Salinator'') as well as separated oviduct and vas deferens (''

Maningrida Maningrida ( Ndjébanna: ''Manayingkarírra'', Kuninjku: ''Manawukan'') is an Aboriginal community in the heart of the Arnhem Land region of Australia's Northern Territory. Maningrida is east of Darwin, and north east of Jabiru. It is on ...

''). There is a free-swimming veliger larva. * Pyramidelloidea is a group of marine snails, ectoparasitic on

bivalves Bivalvia () or bivalves, in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of aquatic molluscs (marine and freshwater) that have laterally compressed soft bodies enclosed by a calcified exoskeleton consis ...

and

annelids The annelids (), also known as the segmented worms, are animals that comprise the phylum Annelida (; ). The phylum contains over 22,000 extant species, including ragworms, earthworms, and leeches. The species exist in and have adapted to vario ...

. They occur from the subtidal to depths of at least 300 m. They do not have a pneumostome and the pallial cavity contains a well developed gill. Operculum is present. Head bears a pair of tentacles, eyes are positioned medially on the head. Radula is lost and there is a long sucking proboscis. The genital system has a spermoviduct leading to a single common opening, but there is an external ciliated groove leading to vas deferes, penis, and a separate male genital opening. Development is through a free-swimming veliger larva. * Glacidorboidea are tiny freshwater snails. The pallial cavity is widely open and filled with water; there is no gill. Anus and the genital opening are within the pallial cavity. Operculum is present. There is one pair of tentacles with eyes positioned medially on the head. Predatory, radula with large median teeth and much reduced lateral teeth. Direct development. * Hygrophila is a clade of exclusively freshwater snails and limpets. They mostly breath oxygen from the air and regularly come to the surface to refill their pallial cavity with fresh air (this may not hold during the winter), but some live permanently submerged; secondary breathing surfaces for absorbing oxygen from water may be present. The basal Chilinidae (some species) and

Latiidae ''Latia'' is a genus of very small, air-breathing freshwater snails or limpets, aquatic pulmonate gastropod molluscs in the superfamily Chilinoidea. ''Latia'' is the only genus in the family Latiidae. Species in this genus are the only freshwa ...

breathe with their pallial cavity oxygen dissolved in the water. Pneumostome is contractible (but not in Chilinidae). Operculum is absent. There is one pair of tentacles that does not bear eyes. Radula has many small, similar teeth per row. In the genital system, the male and female tracts separate after a short spermoviduct (Chilinidae, Latiidae) or there is no common spermoviduct at all. Development is direct. * Ellobiida mostly comprise snails, but also a single slug genus (''

Smeagol Gollum is a Tolkien's monsters, monster with a distinctive style of speech in J. R. R. Tolkien's fantasy world of Middle-earth. He was introduced in the 1937 Fantasy (genre), fantasy novel ''The Hobbit'', and became important in its sequel, ' ...

'') and a limpet genus ('' Trimusculus''). They are distributed from the marine upper

littoral The littoral zone, also called litoral or nearshore, is the part of a sea, lake, or river that is close to the shore. In coastal ecology, the littoral zone includes the intertidal zone extending from the high water mark (which is rarely i ...

to moist terrestrial habitats. The conctractile pneustome is located on the right side of the body (quite posteriorly in

Otina ''Otina ovata'' is a species of small, air-breathing sea snail or sea slug, a marine pulmonate gastropod mollusk in the superfamily Otinoidea. ''Otina ovata'' is the only species in the genus ''Otina''. ''Otina'' is the only genus in the fam ...

) and the pallial cavity functions as a lung. Operculum is absent, retained only in juveniles of '' Blauneria heteroclita''. The is one pair of contractile or partially retractable tentacles (but see ''Trimusculus''). Eyes are typically positioned medially of the tentacles, but in some ''Melampus'' they are on the tentacles at about 1/3 of their length. Radula typically has many similar teeth per row. The structure of the genital tract varies widely, from ''

Pythia Pythia (; ) was the title of the high priestess of the Temple of Apollo (Delphi), Temple of Apollo at Delphi. She specifically served as its oracle and was known as the Oracle of Delphi. Her title was also historically glossed in English as th ...

'' with a common spermoviduct leading to a single genital opening from which an external groove leads to the separate vas deferens and penis, to '' Leucopythia'' with female and male tracts separate from the carrefour and with two openings. There are free-swimming veliger larvae in marine species (e.g. ''

Melampus In Greek mythology, Melampus (; , ''Melampous'') was a legendary soothsayer and healer, originally of Pylos, who ruled at Argos. He was the introducer of the worship of Dionysus, according to Herodotus, who asserted that his powers as a seer ...

''). * Systellommatophora include the mostly intertidal (subtidal to terrestrial)

Onchidiidae Onchidiidae are a family of small, air-breathing sea (and land) slugs. They are shell-less marine (except for two species)preview pulmonate gastropod molluscs. Onchidiidae is the only family within the superfamily Onchidioidea. These animals a ...

as well as fully terrestrial Rathousiidae and

Veronicellidae The Veronicellidae, also known by their common name the leatherleaf slugs, are a family of pulmonate terrestrial slugs. The herbivorous molluscs occur mainly in the tropical and subtropical areas of America, Asia and Africa. They act as interme ...

; all are shell-less slugs. Pallial cavity is used as a lung but may be gretaly reduced (Veronicellidae). Anus and the pneumostome (the latter except for Rathouisiidae) are shifted posteriorly and are located at the end of the body. Operculum is missing. There is one pair of retractable (Onchidiidae) or two pairs of contractile tentacles, eyes are located on tentacle tips. Radula has many similar teeth per row (but this is modified in Rathousiidae). There is a common spermoviduct, but then the male and female tracts divide and the male and female parts have widely separated openings. A free-swimming veliger larva is found in marine species of Ochidiidae, otherwise the development is direct. * Stylommatophora is the most diverse group of land snails and slugs. Pallial cavity forms a spacious, air-filled lung. Anus is located on the right side close to the pneumostome. Operculum is missing. Two pairs of tentacle are retractable and the posterior pair bears eyes on the tips. Radula typically has many small, quite uniform teeth per row. The spermoviduct separates distally into an oviduct and vas deferens, but then there is a single genital opening for both male and female parts. Sperm transfer is via a spermatophore. Development is direct.

References

{{Taxonbar, from1=Q131056539 Gastropod taxa Euthyneura Tectipleura