Strobilopsidae is a

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

of air-breathing land snails,

terrestrial Terrestrial refers to things related to land or the planet Earth. Terrestrial may also refer to: * Terrestrial animal, an animal that lives on land opposed to living in water, or sometimes an animal that lives on or near the ground, as opposed to ...

pulmonate gastropod

mollusk 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 es ...

s in the superfamily

Pupilloidea Pupilloidea is a superfamily of small and very small air-breathing land snails, terrestrial gastropod mollusks in the infraorder '' Pupilloidei'' . Taxonomy This superfamily contains the following families: * Achatinellidae Gulick, 1873 * Ag ...

Taxonomy

The family Strobilopsidae is classified within the informal group Orthurethra, itself belonging to the clade

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 ...

within the clade

Eupulmonata Eupulmonata is a taxonomic clade of air-breathing snails. The great majority of this group are land snails and slugs, but some are marine and some are saltmarsh snails that can tolerate salty conditions. Linnean taxonomy *Suborder Eupulmonata H ...

(according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005). The family Strobilopsidae has no subfamilies according to the taxonomy of the Gastropoda by Bouchet & Rocroi (2005). Some authorities place the family

Spelaeodiscidae Spelaeodiscidae is a family of very small air-breathing land snails, terrestrial pulmonate gastropod mollusks in the superfamily Pupilloidea (according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005). The family Spelaeodiscidae ...

as a subfamily (Spelaeodiscinae) of the Strobilopsidae.Strobilopsidae
MollBase, accessed 20 April 2010.

Genera

Genera within the family Strobilopsidae include: * '' Coelostrobilops'' Pilsbry, 1931 * '' Discostrobilops'' Pilsbry, 1927 * '' Nesostrobilops'' Pilsbry, 1931 * '' Enteroplax'' Gude, 1899 * '' Eostrobilops'' Pilsbry, 1927 Minato H. (1982). 日本のクチミゾガイ類. "''Eostrobilops'' and ''Enteroplax'' from Japan (Strobilopsidae)". 日本貝類学会研究連絡誌 ''The Chiribotan''
CiNii
* '' Strobilops'' Pilsbry, 1893 – type genus of the family Strobilopsidae

Shell description

The

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 ** Thin-shell structure Science Biology * Seashell, a hard o ...

is trochiform, dome-shaped or discoidal and umbilicate. The shell has from 4½ to 6 slowly enlarging whorls. The

aperture In optics, an aperture is a hole or an opening through which light travels. More specifically, the aperture and focal length of an optical system determine the cone angle of a bundle of rays that come to a focus in the image plane. An ...

is small, oblique, with armature of 2 or 3 parietal lamellae and several deeply placed basal folds, all growing continuously from an early neanic stage. The peristome is more or less thickened and expanded, the ends of the lip remote, joined by a parietal callus. The shell, aside from its helicoid shape (not a character of great importance), differs from all Pupillidae in the arrangement of the lamellae and baso-palatal folds. In multidentate Pupillidae the five primary teeth are always recognizable while in ''Strobilops'' only the main parietal lamella and the columellar lamella can certainly be said to correspond, and these are found in so many other land shells that their occurrence is not especially significant. It is possible, however, that upper and lower palatal folds of Pupillidae are represented by teeth 5 (the most right basal tooth) and 2 (second left basal tooth), and the basal fold by tooth 1 (the most left basal tooth). By the accelerated lamellae and folds of the shell, which appear early in the neanic stage, ''Strobilops'' resembles various Tornatellininae (within

Achatinellidae Achatinellidae is a family of tropical air-breathing land snails, terrestrial pulmonate gastropod mollusks in the superfamily Pupilloidea. Taxonomy It was previously the only family in the superfamily Achatinelloidea (according to the taxon ...

). In that family both parietal and palatal folds or laminae are sometimes present in the neanic stage. Various pupillid genera also, such as ''

Orcula ''Orcula'' is a genus of land snails in the family Orculidae. It is the type genus of the family.Páll-Gergely, B., et al. (2013)Subeneric division of the genus Orcula Held 1837 with remarks on Romanian orculid data (Gastropoda, Pulmonata, Orcul ...

'' (

Orculidae Orculidae is a family of mostly minute, air-breathing, land snails; terrestrial pulmonate gastropod mollusks in the superfamily Pupilloidea Pupilloidea is a superfamily of small and very small air-breathing land snails, terrestrial gastr ...

) and ''

Lauria Lauria is a town and ''comune'' of the province of Potenza, in Basilicata, southern Italy, situated near the borders of Calabria. It is a walled, medieval town on the steep side of a hill, with another portion of municipal territory in the pla ...

'' (

Lauriidae Lauriidae is a family of land snails. It is classified within the informal group Orthurethra, itself belonging to the clade Stylommatophora within the clade Eupulmonata (according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005). ...

), have apertural armature during the neanic stage. ''Orcula'' has spiral parietal and columellar lamellae but no basal or palatal folds. ''Lauria'' has basal folds, but they are spaced, ''transverse'' barriers, wholly unlike the adult basal or palatal armature of the species, and differing equally from the folds of immature ''Strobilops'', which from their inception appear to develop continuously into those of the adult shell. It appears likely that the acceleration or early appearance of apertural armature in Tornatellininae, ''Orcula'', ''Lauria'' and ''Strobilops'' has been independent in the four groups, and is not indicative of direct relationship between any of them.

Anatomy

The

urethra The urethra (from Greek οὐρήθρα – ''ourḗthrā'') is a tube that connects the urinary bladder to the urinary meatus for the removal of urine from the body of both females and males. In human females and other primates, the urethra c ...

lies very near the last part of the

intestine The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus. The GI tract contains all the major organs of the digestive system, in humans a ...

. Digestive system: The jaw has numerous ribs.

Radula The radula (, ; plural radulae or radulas) is an anatomical structure used by molluscs 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 ...

with tricuspid central tooth with square basal plate, as large as the bicuspid laterals, the marginals multicuspid.

Reproductive system The reproductive system of an organism, also known as the genital system, is the biological system made up of all the anatomical organs involved in sexual reproduction. Many non-living substances such as fluids, hormones, and pheromones are al ...

Ovotestis An ovotestis is a gonad with both testicular and ovarian aspects. In humans, ovotestes are an infrequent anatomical variation associated with gonadal dysgenesis. The only mammals where ovotestes are not symptomatic of an intersex variation are mol ...

forms two groups of follicles. Penis is continued in a long

epiphallus The reproductive system of gastropods ( slugs and snails) varies greatly from one group to another within this very large and diverse taxonomic class of animals. Their reproductive strategies also vary greatly, see Mating of gastropods. In many ...

and bears a long appendix, with swollen basal and distal divisions, the penial retractor bifurcate, one branch inserted on the epiphallus, the other on the base of the appendix (distally it attaches to the right ocular retractor, according to G. Dallas Hanna). By the structure of the male organs '' Strobilops'' resembles ''

Vallonia ''Vallonia'' is a genus of small air-breathing land snails, terrestrial pulmonate gastropod mollusks in the family Valloniidae. MolluscaBase eds. (2023). MolluscaBase. Vallonia Risso, 1826. Accessed through: World Register of Marine Species ...

'', '' Pupilla'', ''

'', the

, and some other groups are similar in having a bifurcate penial retractor and a long, tripartite appendix. If G. Dallas Hanna is right in stating that the penial retractor is a branch of the right ocular band, this is an important difference from any known Orthurethra. The mouth parts do not differ materially from some Pupillidae.

Fossil distribution

Strobilopsidae appeared in the

Upper Eocene The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', "daw ...

of western Europe in several species having all the external characters of the genus ''Strobilops'', and though the internal structure has not been worked out (in 1927), it is safe to assume that they are closely related to the well-known Oligocene forms following them. In Europe this genus continued in numerous species into the

Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58Upper Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58Astian stage) of

Piedmont it, Piemontese , population_note = , population_blank1_title = , population_blank1 = , demographics_type1 = , demographics1_footnotes = , demographics1_title1 = , demographics1_info1 = , demographics1_title2 ...

. In late

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of ...

beds there are various forms described as ''Helix'', or under the names '' Obbinula'' and '' Pseudostrobilus'', which certainly have some of the characters of ''Strobilops''. All are larger than any ''Strobilops''.

References

This article incorporates public domain text originating from the USA from the reference

Pilsbry H. A. Henry Augustus Pilsbry (7 December 1862 – 26 October 1957) was an American biologist, malacologist and carcinologist, among other areas of study. He was a dominant presence in many fields of invertebrate taxonomy for the better part of a cent ...

(1927). ''

Manual of Conchology George Washington Tryon Jr. (20 May 1838 – 5 February 1888) was an American malacologist who worked at the Academy of Natural Sciences in Philadelphia. Biography George Washington Tryon was the son of Edward K. Tryon and Adeline Savidt. ...

, structural and systematic, with illustrations of the species. Second series: Pulmonata. Volume 28. Geographic Distribution of Pupillidae; Strobilopsidae, Valloniidae and Pleurodiscidae.'' Conchological department Academy of Natural Sciences of Philadelphia, Philadelphia
1
��48. (1927 work without

copyright notice In United States copyright law, a copyright notice is a notice of statutorily prescribed form that informs users of the underlying claim to copyright ownership in a published work. Copyright is a form of protection provided by US law to author ...

External links

* {{Taxonbar, from=Q1949958