Truncatella (gastropod)


Truncatella is a genus of very small land snails with an operculum, terrestrial gastropod mollusks in the family Truncatellidae. These minute snails live in land habitats close to seawater. They walk with a looping action, and the adults have truncated shells. Many of the species are small enough to be considered micromollusks.
Truncatella is the type genus of the family Truncatellidae.

Description

As implied by the name, these snails are notable for the way they modify their elongated shells as they mature, breaking off several of the apical whorls, and forming a relatively smooth seal for the remainder of the shell.

Locomotion

The method of locomotion used by Truncatella is unusual. Instead of gliding over a slime trail using minute waves in its foot, Truncatella uses a very large and muscular proboscis to reach ahead and grasp a surface, at which point the small foot releases its hold and the proboscis contracts to pull the animal forward, after which the entire procedure is usually repeated.

Distribution and habitat

This genus occurs in tropical and subtropical areas. The various species of Truncatella are pantropical in distribution, with a few exceptions such as Truncatella truncatula and Truncatella subcylindrica.
Most of the species in this genus live in a habitat that is neither fully terrestrial nor fully marine: they live under plant debris near high tide level, where they are occasionally wetted with seawater by waves. A small minority of the species are fully terrestrial.
These small snails are typically found associated with drifts of plant material, where their eggs are deposited.
The adaptations of these land snails to the terrestrial environment are not so perfect as they are in the more usual pulmonate land snails, and their terrestrial adaptations may in fact be comparatively recent.

Species

The genus Truncatella was erected by Antoine Risso for T. costulata, which is the type species for this genus.
There are several genera within the Truncatellidae, but the eponymous genus Truncatella is the largest ; other genera in the family are Geomelania, Taheitia, and Blandiella.
There are approximately 30 species in the genus Truncatella, including:
  • † Truncatella arcicostata H.-J. Wang, 1982 Truncatella avenacea Garrett, 1887Truncatella bahamensis Clench and Turner, 1948Truncatella bairdiana C. B. Adams, 1852Truncatella barbadensis L. Pfeiffer, 1857Truncatella brazieri Cox, 1868Truncatella californica Pfeiffer, 1857 - California truncatellaTruncatella caribaeensis Reeve, 1842 - Caribbean truncatellaTruncatella clathrus Lowe, 1832
  • † Truncatella crassolabia H.-Z. Pan, 1982 Truncatella diaphana Gassies, 1869
  • † Truncatella directa Y.-T. Li, 1988 Truncatella granum Garrett, 1872Truncatella guerinii Villa & Villa, 1841
  • † Truncatella hermitei Bardin, 1879
  • † Truncatella hubeiensis Y.-T. Li, 1987
  • † Truncatella jiaozhouensis T. Yu, Salvador, H. Wang, Y. Fang, Neubauer, S. Li, H. Zang & X. Wan, 2021 Truncatella marginata Küster, 1855Truncatella oagariensis
  • † Truncatella obliqua H.-Z. Pan, 1982Truncatella obscura Morelet, 1882
  • † Truncatella parva Y.-T. Li, 1988 Truncatella pfeifferi Martens, 1860Truncatella quadrasi Möllendorff, 1893
  • † Truncatella rabora H.-Z. Pan, 1982 Truncatella reclusa Truncatella rostrata Gould, 1848Truncatella rustica Mousson, 1865
  • † Truncatella sanshuiensis W. Yü & X.-Q. Zhang, 1982 Truncatella scalarina Cox, 1867Truncatella scalaris - ladder truncatellaTruncatella semperi Kobelt, 1884
  • † Truncatella sinensis Y.-T. Li, 1988 Truncatella stimpsonii Stearns, 1872: synonym of Truncatella californica L. Pfeiffer, 1857Truncatella subcylindrica Truncatella teres : synonym of Truncatella marginata Küster, 1855Truncatella thaanumi Clench & Turner, 1948Truncatella truncatula J.P.R. Draparnaud, 1801: synonym of Truncatella subcylindrica Truncatella vincentiana Cotton, 1942
  • † Truncatella wattebledi Benoist, 1878
  • † Truncatella xuanchengensis H.-Z. Pan, 1982 Truncatella yorkensis : synonym of Truncatella guerinii A. Villa & J. B. Villa, 1841

Synonyms

  • † Truncatella antediluviana Deshayes, 1861: synonym of † Bouryia antediluviana Truncatella arcasiana Crosse, 1868: synonym of Taheitia arcasiana Truncatella atomus Philippi, 1841: synonym of Omalogyra atomus Truncatella aurantia A. Gould, 1847: synonym of Truncatella guerinii A. Villa & J. B. Villa, 1841
  • † Truncatella bezanconi Cossmann, 1892: synonym of † Murchisonella bezanconi Truncatella bilabiata L. Pfeiffer, 1840: synonym of Truncatella pulchella L. Pfeiffer, 1839 Truncatella capillacea L. Pfeiffer, 1859: synonym of Truncatella pulchella L. Pfeiffer, 1839Truncatella caribaeensis Reeve, 1842, sensu Clench & Turner, 1948: synonym of Truncatella pulchella L. Pfeiffer, 1839 Truncatella ceylanica Pfeiffer, 1857: synonym of Truncatella marginata Küster, 1855 Truncatella concinna Pease, 1871: synonym of Truncatella guerinii A. Villa & J. B. Villa, 1841
  • † Truncatella costata Cossmann, 1895: synonym of Truncatella wattebledi Benoist, 1878 Truncatella costata L. Pfeiffer, 1839: synonym of Truncatella scalaris Truncatella costellifera Pease, 1871: synonym of Truncatella rustica Mousson, 1865Truncatella costulata Risso, 1826: synonym of Truncatella subcylindrica Truncatella cristata Crosse, 1868: synonym of Truncatella guerinii A. Villa & J. B. Villa, 1841Truncatella cumingii C. B. Adams, 1845: synonym of Truncatella scalaris
  • † Truncatella cylindrata Briart & Cornet, 1887: synonym of † Bouryia cylindrata Truncatella debilis Mousson, 1873: synonym of Truncatella subcylindrica Truncatella desnoyersii : synonym of Truncatella subcylindrica
  • † Truncatella distensa Cossmann, 1888: synonym of † Bouryia distensa Truncatella elongata L. Pfeiffer, 1856: synonym of Geomelania elongata Truncatella fasciata Tapparone Canefri, 1886: synonym of Truncatella guerinii A. Villa & J. B. Villa, 1841Truncatella ferruginea : synonym of Truncatella guerinii A. Villa & J. B. Villa, 1841Truncatella filicosta Poey, 1858: synonym of Geomelania elongata Truncatella floridana Hubricht, 1983: synonym of Truncatella pulchella L. Pfeiffer, 1839Truncatella funiculus Mousson, 1870: synonym of Taheitia funiculus Truncatella fusca Philippi, 1841: synonym of Setia fusca Truncatella futunaensis Mousson, 1871: synonym of Truncatella rustica Mousson, 1865 Truncatella gracilenta W. G. Binney, 1858: synonym of Truncatella californica L. Pfeiffer, 1857 Truncatella gracilenta E. A. Smith, 1897: synonym of Taheitia gracilenta Truncatella haitensis Weinland, 1876: synonym of Geomelania haitensis Truncatella japonica Pilsbry & Y. Hirase, 1905: synonym of Truncatella pfeifferi E. von Martens, 1861 Truncatella juliae de Folin, 1872: synonym of Parthenina juliae Truncatella kiusiuensis Pilsbry, 1902: synonym of Truncatella pfeifferi E. von Martens, 1861 Truncatella labiosa Souverbie, 1862: synonym of Truncatella teres L. Pfeiffer, 1857: synonym of Truncatella marginata Küster, 1855 Truncatella laevigata Risso, 1826: synonym of Truncatella subcylindrica Truncatella laevissima Kuroda, 1956: synonym of Truncatella pfeifferi E. von Martens, 1861Truncatella lirata Poey, 1858: synonym of Geomelania lirata Truncatella lowei Shuttleworth, 1852: synonym of Truncatella subcylindrica Truncatella lubrica Held, 1847: synonym of Platyla polita Truncatella manchurica : synonym of Cecina manchurica A. Adams, 1861 Truncatella mariannarum Quadras & Möllendorff, 1894: synonym of Taheitia mariannarum Truncatella micra Tenison Woods, 1878: synonym of Truncatella scalarina Cox, 1867 Truncatella microlena Monterosato, 1878: synonym of Truncatella subcylindrica
  • † Truncatella minor Briart & Cornet, 1887: synonym of † Bouryia minor Truncatella minuscula de Folin, 1875: synonym of Graphis albida Truncatella modesta C. B. Adams, 1851: synonym of Turbonilla rixtae De Jong & Coomans, 1988 Truncatella montagui R. T. Lowe, 1832: synonym of Truncatella subcylindrica Truncatella pacifica Pease, 1868: synonym of Truncatella guerinii A. Villa & J. B. Villa, 1841
  • † Truncatella parisiensis Deshayes, 1861: synonym of † Bouryia parisiensis Truncatella pulchella Pfeiffer, 1839 - beautiful truncatella - synonyms: Truncatella bilabiata, Truncatella bilabiata bilabiata, Truncatella bilabiata barbadensis.Truncatella pellucida Dohrn, 1860: synonym of Truncatella marginata f. pellucida Dohrn, 1860: synonym of Truncatella marginata Küster, 1855Truncatella porrecta A. Gould, 1847: synonym of Taheitia porrecta Truncatella princeps Dohrn, 1866: synonym of Truncatella rostrata A. Gould, 1847 Truncatella punctata Monterosato, 1878: synonym of Truncatella subcylindrica Truncatella regina Hubricht, 1983: synonym of Truncatella clathrus R. T. Lowe, 1832Truncatella scalariformis C. B. Adams, 1845: synonym of Truncatella scalaris Truncatella scalariformis Reeve, 1842: synonym of Taheitia scalariformis Truncatella schneideri I. Rensch, 1937: synonym of Taheitia schneideri Truncatella semicostulata Jickeli, 1874: synonym of Truncatella marginata f. pellucida Dohrn, 1860: synonym of Truncatella marginata Küster, 1855Truncatella stimpsonii Stearns, 1872: synonym of Truncatella californica L. Pfeiffer, 1857Truncatella striata Reeve, 1842: synonym of Coxiella striata Truncatella striatula Menke, 1843: synonym of Coxiella striatula Truncatella subauriculata Quadras & Möllendorff, 1894: synonym of Taheitia mariannarum Truncatella succinea C. B. Adams, 1845: synonym of Truncatella caribaeensis Reeve, 1842 Truncatella tatarica Schrenck, 1867: synonym of Cecina tatarica Truncatella teres L. Pfeiffer, 1857: synonym of Truncatella marginata Küster, 1855
  • Truncatella truncatula : synonym of Truncatella subcylindrica Truncatella turricula Mousson, 1870: synonym of Taheitia turricula Truncatella ultima I. Rensch, 1937: synonym of Taheitia ultima Truncatella valida L. Pfeiffer, 1846: synonym of Truncatella guerinii A. Villa & J. B. Villa, 1841 Truncatella ventricosa Reeve, 1842: synonym of Tomichia ventricosa Truncatella vitiana A. Gould, 1847: synonym of Truncatella guerinii A. Villa & J. B. Villa, 1841Truncatella wallacei H. Adams, 1865: synonym of Taheitia wallacei
  • † Truncatella weixianensis Youluo, 1978 Truncatella wrighti L. Pfeiffer, 1862: synonym of Geomelania lirata Truncatella yorkensis Cox, 1868: synonym of Truncatella guerinii A. Villa & J. B. Villa, 1841