''Eoacmaea'' is a genus of

sea snail Sea snails are slow-moving marine (ocean), marine gastropod Mollusca, molluscs, usually with visible external shells, such as whelk or abalone. They share the Taxonomic classification, taxonomic class Gastropoda with slugs, which are distinguishe ...

s or true

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, ...

s, marine

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

mollusk Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. The ...

s in the subclass

Patellogastropoda The Patellogastropoda, common name true limpets and historically called the Docoglossa, are members of a major phylogenetic group of marine (ocean), marine gastropods, treated by experts either as a clade or as a taxonomic Order (biology), order. ...

, the true limpets.MolluscaBase eds. (2020). MolluscaBase. Eoacmaea T. Nakano & Ozawa, 2007. Accessed through: World Register of Marine Species at: http://www.marinespecies.org/aphia.php?p=taxdetails&id=456551 on 2020-11-03 ''Eoacmaea'' is the only genus in the family Eoacmaeidae, belonging to the superfamily

Lottioidea Lottioidea is a superfamily of sea snails or limpets, marine gastropod mollusks in the clade Patellogastropoda, the true limpets.MolluscaBase (2018). Lottioidea Gray, 1840. Accessed through: World Register of Marine Species at: http://www.mari ...

Etymology

The generic name ''Eoacmaea'' is composed from the ''Eo'' that mean "early" in Greek and ''

Acmaea ''Acmaea'' is a genus of sea snails, specifically true limpets, marine (ocean), marine gastropod mollusks in the family Acmaeidae, one of the families of true limpets.Bouchet, P.; Rosenberg, G.; Gofas, S. (2014). Acmaea Eschscholtz, 1833. Access ...

'', that is the genus of gastropod in family

Lottiidae Lottiidae is a family (biology), family of sea snails, specifically true limpets, marine (ocean), marine gastropod mollusks in the superfamily Lottioidea and the clade Patellogastropoda (according to the Taxonomy of the Gastropoda (Bouchet & Rocr ...

Taxonomy

The family Eoacmaeidae was established by Nakano & Ozawa (2007) for the genus ''Eoacmaea''. A

cladogram A cladogram (from Greek language, Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an Phylogenetic tree, evolutionary tree because it does not s ...

based on sequences of mitochondrial 12S ribosomal RNA,

16S ribosomal RNA 16S ribosomal RNA (or 16 S rRNA) is the RNA component of the 30S subunit of a prokaryotic ribosome ( SSU rRNA). It binds to the Shine-Dalgarno sequence and provides most of the SSU structure. The genes coding for it are referred to as 16S ...

and cytochrome-c oxidase I (COI) genes showing phylogenic relations of Patellogastropoda by Nakano & Ozawa (2007) and superfamilies based on

World Register of Marine Species The World Register of Marine Species (WoRMS) is a taxonomic database that aims to provide an authoritative and comprehensive catalogue and list of names of marine organisms. Content The content of the registry is edited and maintained by scien ...

: ''Eoacmaea'' is the most

basal group In phylogenetics, basal is the direction of the ''base'' (or root) of a phylogenetic tree#Rooted tree, rooted phylogenetic tree or cladogram. The term may be more strictly applied only to nodes adjacent to the root, or more loosely applied to nodes ...

within Patellogastropoda and ''Eoacmaea'' have diversified from other Patellogastropoda in

Tethys Ocean The Tethys Ocean ( ; ), also called the Tethys Sea or the Neo-Tethys, was a prehistoric ocean during much of the Mesozoic Era and early-mid Cenozoic Era. It was the predecessor to the modern Indian Ocean, the Mediterranean Sea, and the Eurasia ...

Triassic The Triassic ( ; sometimes symbolized 🝈) is a geologic period and system which spans 50.5 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.4 Mya. The Triassic is t ...

Jurassic The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately 143.1 Mya. ...

about 203 million years ago (limits are from 143 to 279 million years ago).

Species

Species within the genus ''Eoacmaea'' include: * ''

Eoacmaea albonotata ''Eoacmaea albonotata'' is a species of sea snail, a true limpet, a marine gastropod mollusk in the family Eoacmaeidae ''Eoacmaea'' is a genus of sea snails or true limpets, marine (ocean), marine gastropod mollusks in the subclass Patelloga ...

'' (Smith, 1901) * ''

Eoacmaea calamus ''Eoacmaea calamus'' is a species of sea snail, a true limpet, a marine gastropod mollusk in the family Eoacmaeidae ''Eoacmaea'' is a genus of sea snails or true limpets, marine (ocean), marine gastropod mollusks in the subclass Patellogastro ...

'' (Crosse & Fischer, 1864) * ''

Eoacmaea ceylanica ''Eoacmaea ceylanica'' is a species of sea snail, a true limpet, a marine gastropod mollusk in the family Eoacmaeidae ''Eoacmaea'' is a genus of sea snails or true limpets, marine (ocean), marine gastropod mollusks in the subclass Patellogast ...

'' (E.A. Smith, 1911) * ''

Eoacmaea chamorrorum ''Eoacmaea chamorrorum'' is a species of sea snail, a true limpet, a marine gastropod mollusk in the family Eoacmaeidae ''Eoacmaea'' is a genus of sea snails or true limpets, marine (ocean), marine gastropod mollusks in the subclass Patelloga ...

'' (Lindberg & Vermeij, 1985) * ''

Eoacmaea conoidalis ''Eoacmaea conoidalis'' is a species of sea snail, a true limpet, a marine gastropod mollusk in the family (biology), family Eoacmaeidae, one of the families of true limpets. Description Distribution References

Eoacmaeidae Gastropo ...

'' (Pease, 1868) * ''

Eoacmaea ivani ''Eoacmaea ivani'' is a species of sea snail, a true limpet, a marine gastropod mollusk in the family Eoacmaeidae ''Eoacmaea'' is a genus of sea snails or true limpets, marine (ocean), marine gastropod mollusks in the subclass Patellogastropo ...

'' (Christiaens, 1975) * '' Eoacmaea javanica'' (Nakano, Aswan & Ozawa, 2005) * '' Eoacmaea mauritiana'' (Pilsbry, 1891) * '' Eoacmaea omanensis'' (Christiaens, 1975) * '' Eoacmaea perfestiva'' (Faber, 2004) * '' Eoacmaea profunda'' (Deshayes, 1863) - type species * '' Eoacmaea pustulata'' (Helbling, 1779) * '' Eoacmaea semirubida'' (Dall, 1914)

References

{{Taxonbar, from=Q5381563