{{Short description|Species of gastropod}} {{Use dmy dates|date=December 2023}} {{Speciesbox | image = Pseudofusulus varians.png | image_caption = Common and albinistic colour forms of ''Pseudofusulus varians'' | display_parents = 3 | genus = Pseudofusulus | parent_authority = Nordsieck, 1977<ref>{{in lang|de}} Nordsieck H. (1977). "Zur Anatomie und Systematik der Clausilien, XVIII. Neue Taxa rezenter Clausilien". ''Archiv für Molluskenkunde'' '''108'''(1/3): 73–107. page 96.</ref> | species = varians | authority = (C. Pfeiffer, 1828)<ref name="Pfeiffer 1828">{{in lang|de}} Pfeiffer C. (1828). [http://resolver.sub.uni-goettingen.de/purl?PPN620452897 "Naturgeschichte deutscher Land- und Süsswasser-Mollusken"]. Dritte Abtheilung. pp. I-VI, 1–84 pp., Taf. I-VIII. Weimar. (Landes-Industrie-Comptoir). p. 40, Taf. 7, Fig. 24-25.</ref> | synonyms = {{Species list | Helix (Clausilia) diaphana | C. Pfeiffer, 1828 | Helix (Clausilia) varians | C. Pfeiffer, 1828 }} | synonyms_ref = <ref>{{cite WoRMS |title=''Pseudofusulus'' |id=996091 |access-date=13 November 2021}}</ref> }}
'''''Pseudofusulus varians''''' is a species of air-breathing land snail, a terrestrial pulmonate gastropod mollusk in the family Clausiliidae.
Genus '''''Pseudofusulus''''' is monotypic genus (contains one species only) with ''Pseudofusulus varians'' as its type species.
It is a relict species from Atlantic period of the Holocene, inhabiting exclusively nature beech and scree forests in Europe.<ref name="Lacina 2011"/>
== Distribution == The distribution of this species is Eastern Alpine and Western Carpathian.<ref name="Lacina 2009"/> The type locality is the High Alps in Styria, Austria.<ref name="Pfeiffer 1828"/>
The key area of its range is in the Western Alps (from the south-western part of the Alps to Croatia, and also to the Dolomites in the southern Tyrol).<ref name="Lacina 2011"/> * Austria<ref name="Lacina 2011"/> * Germany<ref name="Lacina 2011"/> * Czech Republic – 7 confirmed sites in Ore Mountains in Bohemia,<ref name="Lacina 2011"/> locally extinct in Moravia.<ref name="Lacina 2011"/> Already Vojen Ložek has been calling for the effective conservation of this species in the 1980s.<ref name="Lacina 2011"/><ref>{{in lang|cs}} Ložek V. (1985). "Z červené knihy našich měkkýšů – je ohrožen vřetenec horský?". ''Živa'' '''33''': 221.</ref> It is one of the most endangered species in the Czech Republic, restricted to hidden and undisturbed natural deciduous forests.<ref name="AB"/> Originally it was known from 16 sites in the Ore Mountains (Krušné Hory Mts.), in the northwestern Bohemia, Czech Republic and one site on the slope of Smrk Mount in the Moravian-Silesian Beskids (Moravskoslezské Beskydy Mts.), East Moravia, Czech Republic.<ref name="Lacina 2011"/> ** extinct in Moravia: The forest at the only (but well populated) locality in the Moravia has been seriously damaged by air pollution from factories (such as Třinec Iron and Steel Works and others) jointly with the 20 °C dropping of temperatures in inversion on 31 December 1978.<ref name="Lacina 2011"/> The nearly all pollution-damaged stand died out at the southwestern slope on the Smrk Mount.<ref name="Lacina 2011"/> ** in Bohemia: The occurrence of the snail was recently confirmed only at seven sites in the Krušné Hory Mts.<ref name="Lacina 2011"/> Remaining sites were destroyed due to human impacts, mainly acid rains and insensitive forest management<ref name="Lacina 2011"/> mainly due to removal of dead wood and clearcutting.<ref name="AB"/> Therefore, its populations survived only in forest patches hidden in hardly accessible places.<ref name="Lacina 2011"/> * Slovakia – in the eastern part of Low Tatras, in the peak level of Poľana, Klenovský Vepor Mount in the Vepor Mountains, Muránska planina and the Ondrejsko in Slovak Paradise is the easternmost.<ref name="Lacina 2011"/> All of these records in the Slovakia are coming from 1960s–1970s and there has been no verification since.<ref name="Lacina 2011"/> * Croatia<ref name="Lacina 2011"/> * Italy * and others
left|thumb|shells of ''Pseudofusulus varians''
== Description == The shell is horny or greenish brown and finely ribbed.<ref name="AB"/> The shell has 9–10 whorls.<ref name="AB"/> The apertural margin is detached.<ref name="AB"/> Columellaris is deep inside and forked, hardly visible in a perpendicular view.<ref name="AB"/> Palatal wall is white and prominent.<ref name="AB"/> There is no lunula.<ref name="AB"/> Subcolumellaris is very close to basal furrow, visible in an oblique view.<ref name="AB"/> Clausilium is not very concave.<ref name="AB"/>
The width of the shell is 2.2–3 mm.<ref name="AB"/> The height of the shell is 9–12 mm.<ref name="AB"/>
== Habitat == ''Pseudofusulus varians'' is very exacting on the quality of its environment and its populations are small and quite scattered in the whole of its range.<ref name="Lacina 2011"/>
It lives in virgin-like forests<ref name="Lacina 2009">{{in lang|cs}} Lacina A. & Horsák M. (2009). [http://ziva.avcr.cz/?c=1451 "Jak se vede vřetenatci horskému – z červené knihy našich měkkýšů"] ["Is the land Snail ''Pseudofusulus varinas'' Doing Well? From the Czech Republic's Red Book of Molluscs"]. ''Živa'', Praha '''LVII'''(2): 73–74. [http://ziva.avcr.cz/?c=1451&lng=en English abstract].</ref> and old-growth forest with fallen dead wood (coarse woody debris) in montane and submontane.<ref name="Lacina 2011"/> It is found in humid and shady habitats in woods, under ground litter and stones, in mountains.<ref name="AB"/> In the Czech Republic it is strictly associated with trees, restricted to undisturbed and hardly accessible natural beech forests.<ref name="AB"/> ''Pseudofusulus varians'' is strictly dendrophilous species, so the main threat is dead wood removing and clearcutting.<ref name="Lacina 2011"/>
As it is endangered in the whole Europe, it is very important to protect its modern sites.<ref name="Lacina 2011"/>
==References== This article incorporates public domain text from the reference<ref name="AB">[http://www.animalbase.uni-goettingen.de/zooweb/servlet/AnimalBase/home/species?id=258 "Species summary for ''Pseudofusulus varians''"]. AnimalBase, last modified 23 March 2011, accessed 27 April 2011.</ref> and CC-BY-3.0 text from the reference<ref name="Lacina 2011">{{in lang|cs}} Lacina A. (2011). "Poznámky k ekologii, rozšíření a ochraně vřetence horského (''Pseudofusulus varians'') v České republice. [Notes to the ecology, distribution and protection of Pseudofusulus varians in the Czech Republic]". ''Malacologica Bohemoslovaca'' '''10''': 18–23. [http://mollusca.sav.sk/pdf/10/10.Lacina.pdf PDF].</ref> {{Reflist}}
==External links== *{{Commons category-inline|Pseudofusulus varians}}
{{Taxonbar|from2=Q7254795|from1=Q21229962}}
Category:Clausiliidae Category:Gastropods described in 1828 Category:Monotypic gastropod genera Category:Taxa named by Carl Jonas Pfeiffer