Archaeogastropoda
Encyclopedia
Archaeogastropoda was a taxonomic order of sea snail
s used in older classifications of gastropods, i.e. snail
s and slug
s. Archeogastropoda are marine
prosobranch gastropod mollusks, mainly herbivore
s, typically having two gill
s and a double-chambered heart, with the eggs and sperm discharged directly into the water. They were traditionally regarded as a relatively primitive group.
This older classification of the gastropods is based on the classification of Johannes Thiele
(1925). This classification was not based on true phylogenetic relationships, but on more general affinities between the groups. In the last few years, two new cladistic taxonomies of the gastropods have been published (in 1997 and 2005). This has led to an extensive reclassification of gastropod taxa. The taxon Archaeogastropoda was found to be a paraphyletic group, and therefore unacceptable in a strictly cladistic classification.
In the 1997 classification, most of the former Archaeogastropoda were included in:
A more detailed classification can be found on Gastropoda
.
Sea snail
Sea snail is a common name for those snails that normally live in saltwater, marine gastropod molluscs....
s used in older classifications of gastropods, i.e. snail
Snail
Snail is a common name applied to most of the members of the molluscan class Gastropoda that have coiled shells in the adult stage. When the word is used in its most general sense, it includes sea snails, land snails and freshwater snails. The word snail without any qualifier is however more often...
s and slug
Slug
Slug is a common name that is normally applied to any gastropod mollusc that lacks a shell, has a very reduced shell, or has a small internal shell...
s. Archeogastropoda are marine
Marine (ocean)
Marine is an umbrella term. As an adjective it is usually applicable to things relating to the sea or ocean, such as marine biology, marine ecology and marine geology...
prosobranch gastropod mollusks, mainly herbivore
Herbivore
Herbivores are organisms that are anatomically and physiologically adapted to eat plant-based foods. Herbivory is a form of consumption in which an organism principally eats autotrophs such as plants, algae and photosynthesizing bacteria. More generally, organisms that feed on autotrophs in...
s, typically having two gill
Gill
A gill is a respiratory organ found in many aquatic organisms that extracts dissolved oxygen from water, afterward excreting carbon dioxide. The gills of some species such as hermit crabs have adapted to allow respiration on land provided they are kept moist...
s and a double-chambered heart, with the eggs and sperm discharged directly into the water. They were traditionally regarded as a relatively primitive group.
This older classification of the gastropods is based on the classification of Johannes Thiele
Johannes Thiele
Johannes Thiele, full name Karl Hermann Johannes Thiele was a German zoologist specialized in malacology. His Handbuch der systematischen Weichtierkunde is a standard work...
(1925). This classification was not based on true phylogenetic relationships, but on more general affinities between the groups. In the last few years, two new cladistic taxonomies of the gastropods have been published (in 1997 and 2005). This has led to an extensive reclassification of gastropod taxa. The taxon Archaeogastropoda was found to be a paraphyletic group, and therefore unacceptable in a strictly cladistic classification.
In the 1997 classification, most of the former Archaeogastropoda were included in:
- subclass EogastropodaEogastropodaEogastropoda was a previously used taxonomic category of snails or gastropods, a subclass which was erected by Ponder and Lindberg in 1997. It was one of two great divisions of the class Gastropoda, the snails. The other subclass of gastropods was the Orthogastropoda.Eogastropoda were the more...
- order PatellogastropodaPatellogastropodaPatellogastropoda, common name true limpets and historically called Docoglossa, is a major phylogenetic group of marine gastropods, seen either as a clade or as a taxonomic order.-Taxonomy:Patellogastropoda was proposed by David R...
(limpets)
- order Patellogastropoda
- subclass OrthogastropodaOrthogastropodaOrthogastropoda was a major taxonomic groupings of snails and slugs, an extremely large subclass within the huge class Gastropoda according to the older taxonomy of the Gastropoda ....
- Superorder Vetigastropoda VetigastropodaVetigastropoda is a major taxonomic group of sea snails, marine gastropod mollusks that form a very ancient lineage. Taxonomically Vetigastropoda are sometimes treated as an order although they are a clade in Bouchet and Rocroi, 2005....
Salvini-Plawen, 1989 - Superorder Neritaemorphi Koken, 1896 (with the order Neritopsina Cox & Knight, 1960).
- Superorder Vetigastropoda
A more detailed classification can be found on Gastropoda
Gastropoda
The Gastropoda or gastropods, more commonly known as snails and slugs, are a large taxonomic class within the phylum Mollusca. The class Gastropoda includes snails and slugs of all kinds and all sizes from microscopic to quite large...
.
Older system of classification
- Order Archaeogastropoda
- Superfamily PleurotomariaceaPleurotomariaceaThe superfamily Pleurotomariacea, based on Swainson, 1840 and described in the Treatise on Invertebrate Paleontology, was established for mostly conispiral, but also discoidal and auriform shells that have a nacreous, aragonite, inner layer.The Pleurotomariacea, now often seen as...
- Family PleurotomariidaePleurotomariidaePleurotomariidae, common name the '"slit snails", is a family of large marine gastropods in the clade Vetigastropoda. This family is very ancient; there were numerous species in the geological past. It is currently represented by a group of species that live only in deep water...
- Family Haliotidae
- Family ScissurellidaeScissurellidaeScissurellidae, sometimes known by the common name little slit snails, are a taxonomic family of minute sea snails, marine gastropod molluscs or micromolluscs in the clade Vetigastropoda...
- Family Pleurotomariidae
- Superfamily Fissurellacea
- Family Fissurellidae
- Superfamily Patellacea
- Family PatellidaePatellidaePatellidae is a taxonomic family of sea snails or true limpets, marine gastropod molluscs in the clade Patellogastropoda.Patellidae is the only family in the superfamily Patelloidea...
- Family Acmaeidae
- Family LepetidaeLepetidaeLepetidae is a family of sea snails or small, deep-water true limpets, marine gastropod molluscs in the clade Patellogastropoda the true limpets.- Taxonomy :...
- Family Patellidae
- Superfamily Trochacea
- Family CalliostomatidaeCalliostomatidaeCalliostomatidae is a family of sea snails within the superfamily Trochoidea and the clade Vetigastropoda.- Description :The Calliostomatidae are unusually diverse. They are characterized by a stepped spire and a pointy aperture. They may possess or lack an umbilicus. The columella is sometimes...
- Family TrochidaeTrochidaeThe Trochidae, common name top snails, are a taxonomic family of very small to large sea snails, marine gastropod molluscs in the clade Vetigastropoda ....
- Family StomatellidaeStomatellidaeStomatellidae is a family of small marine gastropods now included in the Vetigastropoda.-Taxonomy:In the earlier classification of the Treatise the Stomatellidae was included in the Archaeogastropoda which is now largely abandoned in favor of the more newly defined Vetigastropoda.Stomatellidae is a...
- Family Cyclostrematidae
- Family TurbinidaeTurbinidaeTurbinidae, the turban snails, are a family of small to large marine gastropods. Turbinidae have a strong, thick calcareous operculum readily distinguishing them from the somewhat similar Trochidae or top snails, which have a corneous operculum...
- Family PhasianellidaePhasianellidaePhasianellidae common name the "pheasant shells" or "pheasant snails" is a family of small sea snails with calcareous opercula, marine gastropod mollusks in the clade Vetigastropoda ....
- Family Calliostomatidae
- Superfamily Neritacea
- Family NeritidaeNeritidaeNeritidae, common name the nerites, is a taxonomic family of small to medium-sized saltwater and freshwater snails which have a gill and a distinctive operculum, marine, brackish water and freshwater gastropod mollusks in the order Neritoida....
- Family HelicinidaeHelicinidaeHelicinidae is a family of small tropical land snails which have an operculum. They are terrestrial operculate gastropod mollusks in the superfamily Helicinoidea....
- Family HydrocenidaeHydrocenidaeHydrocenidae is a poorly-known taxonomic family of minute land snails or cave snails with an operculum, terrestrial gastropod mollusks or micromollusks in the clade Cycloneritimorpha....
- Family Neritidae
- Superfamily Pleurotomariacea
External links
- Sasaki T. (1998). "Comparative anatomy and phylogeny of the recent Archaeogastropoda (Mollusca: Gastropoda)". Bulletin 38. Tokio.