Euconulidae is a taxonomic

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 minute, air-breathing

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 molluscs, terrestrial gastropod mollusks that have gastropod shell, shel ...

s, terrestrial

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 ...

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 or

micromollusk A micromollusc is a shelled mollusc which is extremely small, even at full adult size. The word is usually, but not exclusively, applied to marine molluscs, although in addition, numerous species of land snails and freshwater molluscs also ...

s in the superfamily Trochomorphoidea. This land snail family is closely allied to the Zonitidae, the glass snails.

Taxonomy

The family Euconulidae was originally placed within the superfamily Gastrodontoidea according to the

taxonomy of the Gastropoda (Bouchet & Rocroi, 2005) The taxonomy of the Gastropoda as it was revised in 2005 by Philippe Bouchet and Jean-Pierre Rocroi is a system for the scientific classification of gastropod mollusks (Gastropods are a taxonomic class of animals which consists of snails and sl ...

. Since 2017, its classification has been revised and it now belongs to the superfamily Trochomorphoidea

Distribution

The distribution of the Euconulidae includes the

Nearctic The Nearctic realm is one of the eight biogeographic realms constituting the Earth's land surface. The Nearctic realm covers most of North America, including Greenland, Central Florida, and the highlands of Mexico. The parts of North America ...

, the western-

Palearctic The Palearctic or Palaearctic is a biogeographic realm of the Earth, the largest of eight. Confined almost entirely to the Eastern Hemisphere, it stretches across Europe and Asia, north of the foothills of the Himalayas, and North Africa. Th ...

, the eastern-Palearctic, the

Neotropical The Neotropical realm is one of the eight biogeographic realms constituting Earth's land surface. Physically, it includes the tropical terrestrial ecoregions of the Americas and the entire South American temperate zone. Definition In biogeogra ...

zone, the

Ethiopia Ethiopia, officially the Federal Democratic Republic of Ethiopia, is a landlocked country located in the Horn of Africa region of East Africa. It shares borders with Eritrea to the north, Djibouti to the northeast, Somalia to the east, Ken ...

n zone, Malagasy, south-eastern Asia, Australia, Polynesia and

Hawaii Hawaii ( ; ) is an island U.S. state, state of the United States, in the Pacific Ocean about southwest of the U.S. mainland. One of the two Non-contiguous United States, non-contiguous U.S. states (along with Alaska), it is the only sta ...

. Humidity, temperature, rainfall, and foliar dripping derived from dew, mist, and rain, affect the behavior and substrate selection of small terrestrial molluscs, such as ''Tikoconus costarricanus'', which inhabit shrubs in humid tropical montane forests. There is also a preference of some parts of a leaf, for example, in some cases the lower side is preferred, possibly because it has better humidity and protects small snails from the impact of raindrops.

Shell description

These minute snails have a

shell Shell may refer to: Architecture and design * Shell (structure), a thin structure ** Concrete shell, a thin shell of concrete, usually with no interior columns or exterior buttresses Science Biology * Seashell, a hard outer layer of a marine ani ...

which is roundly conical and broad-based, like the shape of an old-fashioned European woven bee hive or

skep A beehive is an enclosed structure which houses honey bees, subgenus ''Honey bee, Apis.'' Honey bees live in the beehive, raising their young and producing honey as part of their seasonal cycle. Though the word ''beehive'' is used to describe th ...

. For this reason these snails are sometimes known as "hive snails". The shells of most Euconulidae are only about 3 mm in size, amber-colored and translucent.

Anatomy

In this family, the number of

haploid Ploidy () is the number of complete sets of chromosomes in a cell (biology), cell, and hence the number of possible alleles for Autosome, autosomal and Pseudoautosomal region, pseudoautosomal genes. Here ''sets of chromosomes'' refers to the num ...

chromosome A chromosome is a package of DNA containing part or all of the genetic material of an organism. In most chromosomes, the very long thin DNA fibers are coated with nucleosome-forming packaging proteins; in eukaryotic cells, the most import ...

s lies between 26 and 30 (according to the values in this table).Barker G. M.: Gastropods on Land: ''Phylogeny, Diversity and Adaptive Morphology''. in Barker G. M. (ed.):
The biology of terrestrial molluscs
'. CABI Publishing, Oxon, UK, 2001, . 1-146, cited pages: 139 and 142.

Genera

Subfamilies and genera in the family Euconulidae include: Euconulinae * '' Afroconulus'' Van Mol & van Bruggen, 1971MolluscaBase (2018). Euconulinae H.B. Baker, 1928. Accessed through: World Register of Marine Species at: http://marinespecies.org/aphia.php?p=taxdetails&id=994926 on 2018-09-14 * '' Afroguppya'' de Winter & Bruggen, 1992 * '' Afropunctum'' F. Haas, 1934 * '' Cancelloconus'' I. Rensch, 1932 * '' Coneuplecta'' Möllendorff, 1893 * '' Diepenheimia'' Preston, 1913 * '' Discoconulus'' Reinhardt, 1883 * '' Dryachloa'' F. G. Thompson & H. G. Lee, 1980 * '' Euconulus'' Reinhardt, 1883 - type genus of the family Euconulidae * '' Guppya'' Mörch, 1867 * '' Habroconus'' Crosse & P. Fischer, 1872 * '' Kororia'' H. B. Baker, 1941 * '' Louisia'' Godwin-Austen, 1908 * '' Luchuconulus'' Pilsbry, 1928 * '' Palaua'' H.B. Baker, 1941 * '' Papuarion'' Van Mol, 1973 * '' Parasitala'' Thiele, 1931 * '' Sabalimax'' Tillier & Bouchet, 1989 * '' Serostena'' Iredale, 1941 * '' Tikoconus'' Barrientos, 2019 * '' Velifera'' W.G. Binney, 1879 Microcystinae * '' Allenoconcha'' Preston, 1913 * '' Aukena'' Baker, 1940Bouchet P. & Abdou A. (2001). "Recent Extinct Land Snails (Euconulidae) from the Gambier Islands with Remarkable Apertural Barriers". ''

Pacific Science ''Pacific Science'' is a quarterly multidisciplinary peer-reviewed scientific journal covering the biological and physical sciences of the Pacific basin, focusing especially on biogeography, ecology, evolution, geology and volcanology, oceanograph ...

'' 55(2): 121-127. . * '' Cookeana'' * ''

Diastole Diastole ( ) is the relaxed phase of the cardiac cycle when the chambers of the heart are refilling with blood. The contrasting phase is systole when the heart chambers are contracting. Atrial diastole is the relaxing of the atria, and ventricul ...

'' Gude, 1913 * '' Faunulena'' * '' Greenwoodoconcha'' * '' Hiona'' Cooke, 1940 * '' Innesoconcha'' Iredale, 1944 * '' Iredaleoconcha'' Preston, 1913 * '' Kaala'' * '' Kusaiea'' Baker, 1938 * '' Lamprocystis'' * '' Liardetia'' * '' Melloconcha'' Iredale, 1944 * '' Mendana'' * '' Microcystis'' * '' Nancibella'' * '' Periclocystis'' * '' Philonesia'' Sykes, 1900 * '' Piena'' * '' Pukaloa'' * '' Tengchiena''

Cladogram

The following

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 ...

shows the phylogenic relationships of this family with the other families within the limacoid clade:Hausdorf B. (2000). "Biogeography of the Limacoidea sensu lato (Gastropoda: Stylommatophora): Vicariance Events and Long-Distance Dispersal". '' Journal of Biogeography'' 27(2): 379-390.
JSTOR

References

External links

* {{Taxonbar, from=Q120147 Taxa described in 1928