Fragile Chloraea Snail (Leytea leytensis)
The Fragile Chloraea Snail was described in 1841; it is apparently endemic to the island of Leyte in the Philippines.
The species is thought to be extinct.
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syn. Chloraea fragilis (Sowerby), Helix leytensis Pfeiffer
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edited: 12.02.2024
The Concealed Helicostyla Snail was described in 1841.:
“Imperforate, ovate-oblong, solid; yellowish, ornamented with two bands and a basal area of chestnut, veiled with a whitish hydrophanous cuticle. Spire conic, apex obtuse. Whorls 6, scarcely convex, the last about equal to three-sevenths the entire length. Columella nearly straight, slightly dilated, rose-white; aperture oval, milk-white within; peristome somewhat thickened, narrowly reflexed, brown-edged.” [1]
This species is apparently restricted to the Camotes Islands east of Cebu Island, Philippines; it is possibly extinct now.
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References:
[1] George W. Tryon; Henry A. Pilsbry; a. o.: Manual of Conchology. Second series: Pulmonata. Vol 8: Helicidae – Volume VI. 1892
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Depiction from: ‘George W. Tryon; Henry A. Pilsbry; a. o.: Manual of Conchology. Second series: Pulmonata. Vol 8: Helicidae – Volume VI. 1892’
(public domain)
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edited: 23.08.2022
Big Anixa Snail (Helicostyla propitia)
The Big Anixa Snail species was described in 1907, it is endemic to the island of cebu, Philippines..
This is a rather large species with shells reaching up to 4 cm in diameter, it is closely related to Morelet’s Anixa Snail (Anixa moreleti) and differes from that species in being much larger, and having a thicker shell with a much lighter-colored epidermis. [1]
This species appears in lists of extinct species, but I’m not quite sure if it indeed is extinct, since other, closely related species, also having been considered extinct, subsequently actually rediscovered.
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References:
[1] Hugh C. Fulton: Descriptions of new species of Trochomorpha, Cochlostyla, Amphidromus, Bulimulus, Drymaeus, Placostylus, Stenogyra, Leptopoma, Cyclophorus, Cyclotus, and Alycaeus. The Annals and magazine of natural history; Zoology, Botany, and Geology ser. 7, Vol. 19(110): 149-157. 1907
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edited: 17.06.2020
The Mikuriya Satsuma Snail, described in 1902, was found in the Shizuoka Prefecture on the island of Honshu, Japan.
The species is officially considered endangered or vulnerable but is apparently already extinct. [1]
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References:
[1] Robert H. Cowie; Claire Régnier; Benoît Fontaine; Philippe Bouchet. Measuring the Sixth Extinction: what do mollusks tell us? The Nautilus 131(1): 3-41. 2017
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edited: 21.04.2022
Ogasawaran Mandarina Snail (Mandarina ogasawarana)
This species was described in 1999, it is known exclusively from Holocene deposits at Nankinhama on southern Hahajima Island, Ogasawara Islands, Japan.
The Ogasawaran Mandarina Snail was a medium-sized member of its genus, reaching average shell heigths of about 2 cm, they were characterized by a flat spire and a relatively large body whorl with a weak peripheral angulation and other characters.
The species disappeared at around 2000 BCE, most likely because of environmental changes due to natural climatic changes that resulted in a rise of temperatures creating a dryer climate. [1]
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References:
[1] Satoshi Chiba: A new species of land snail of the genus Mandarina (Gastropoda: Pulmonata) from Hahajima of the Bonin Islands, Western Pacific: a species that became extinct after 2000 yr. B.P.. Bulletin of the National Science Museum (C) 25(3-4): 121–127. 1999
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edited: 19.04.2019
Morelet’s Anixa Snail (Anixa moreleti)
Morelet’s Anixa Snail was described in 1848, it is endemic to the island of Cebu in the Philippines.
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“Wie Pfeiffer richtig vermuthete, lag ihm ein abgeriebenes Stück vor; frische sind mit einer gelbbraunen, gestriemten und blitzartig gestreiften Oberhaut versehen. Sie ist höheren Formen der vorigen Art [Anixa callodes] im ganzen ähnlich, aber grösser, die Oberhaut besitzt einen starken Fettglanz und die letzte Windung zeigt an der Peripherie eine eigenthümliche Abplattung. Die Art wurde uns in einiger Anzahl von einem Einwohner des Dorfes Boljoon gebracht, doch konnten wir leider nicht constatieren, ob sie mit der von dort stammenden hohen Form der C. carbonaria zusammenlebt. oder ob sie, wich ich annehmen möchte, aus einem anderen Winkel desrselben Insel stammt. Jedenfalls ist sie aus keinem anderen Theil der Insel gebracht worden und dürfte ganz local beschränkt sein. Ihr näheres Vaterland war bisher noch nicht bekannt.“
translation:
“As Pfeiffer suspected rightly, he had an abraded specimen in front of him; fresh ones have a yellow-brown, streaked and zigzagy striped epidermis. It is generally similar to higher forms of the previous species [Anixa callodes], but is larger, the epidermis has a strong oily sheen on it and the last whorl shows a peciular flattening on the periphery. The species was brought to us in some numbers by a resident of the village of Bojoon, but unfortunately we could not establish whether it lives together with the high form of C. carbonaria. or whether, as I like to suppose, comes from another corner of the same island. In any case, it has not been brought from any other part of the island and should be very likely absolutely local. Its closer homeland has not been known yet.” [1]
The shells reach sizes of about 2,5 cm in height.
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References:
[1] C. Semper: Reisen im Archipel der Philippinen: Wissenschaftliche Resultate, zehnter Band: Landmollusken. Ergänzungen und Berichtigungen zum III. Bande: Die Landmollusken von Dr. O. F. von Möllendorff. Nach dessen Tode auf Grund seinen Nachlasses fortgeführt von Dr. Wilhelm Kobelt und Frau Gertrud Winter, geb. von Möllendorff. Achtes Heft. Wiesbaden; C. W. Kreidel’s Verlag 1910
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edited: 17.06.2020
Pfeiffer’s Anixa Snail (Anixa pfeifferi)
Pfeiffer’s Anixa Snail was described in 1889 (?), it originates from a locality near of what today is the city of Dalaguete at the eastern coast of the island of Cebu in the Philippines.:
“Auch die Verbreitung dieser Art ist sehr beschränkt: weiter nach Südost tritt schon bei Boljoon eine Form der C. carbonaria an ihre Stelle, auf der Westseite jenseits der Centralkette haben wir C. zebuensis bereits erwähnt.”
translation:
“The distribution of this species is also very limited. further to the southeast, a form of the C. carbonaria takes its place, on the western side beyond the central ridge we already have mentioned C. zebuensis.” [1]
The shells of this species reach sizes of 2 cm in heigth and nearly 4 cm in diameter.
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References:
[1] C. Semper: Reisen im Archipel der Philippinen: Wissenschaftliche Resultate, zehnter Band: Landmollusken. Ergänzungen und Berichtigungen zum III. Bande: Die Landmollusken von Dr. O. F. von Möllendorff. Nach dessen Tode auf Grund seinen Nachlasses fortgeführt von Dr. Wilhelm Kobelt und Frau Gertrud Winter, geb. von Möllendorff. Achtes Heft. Wiesbaden; C. W. Kreidel’s Verlag 1910
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edited: 17.06.2020
Minamizaki Mandarina Snail (Mandarina luhuana ssp. luhuana)
This species was described in 1839, it is known exclusively from subfossil specimens that were recovered from Holocene deposits at Minamizaki in the southern part of Chichijma Island, Ogasawara Islands, Japan.
The shells are large and very thick, they have an average size of about 4 cm in diameter, they are white and always bear two to four brown bands. [1]
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syn. Euhadra luhuana (Sowerby), Helix luhuana Sowerby, Mandarina ruschenbergi (Pilsbry), Nanina ruschenbergi Pilsbry
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References:
[1] Satoshi Chiba: Taxonomic revision of the fossil land snail species of the genus Mandarina in the Ogasawara Islands. Paleontological Research 11(4): 317-329. 2007
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edited: 19.04.2019
Minamijima Mandarina Snail (Mandarina luhuana ssp. minamijimana)
The Minamijima Mandarina Snail was described in 2007, it is known exclusively from Holocene deposits on the island of Minamijima, Ogasawara Islands, Japan; it was originally thought to be identical with Mandarina luhuana (Sowerby) and was named as Mandarina luhuana f. A Chiba.
The shells reach sizes of about 2.2 cm in height and up to 4.2 cm in diameter; they differ from those of the nominate race in having a higher spire, a smaller number of whorls, a relative narrower umbilicus and a thinner shell, the shells are furthermore darker in color. [1]
“Many fossil specimens of this species are found in the sand dune.” [1] (see also photo below)
The species likely disappeared at the Pleistocene/Holocene border due to natural climate changes.
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References:
[1] Tadashige Habe: Fossil land snails from Minami-jima, Bonin Islands. Science Reports of the Tohoku University, Special Volume 6 (Hatai Memorial Volume): 51-53. 1973
[2] Satoshi Chiba: Taxonomic revision of the fossil land snail species of the genus Mandarina in the Ogasawara Islands. Paleontological Research 11(4): 317-329. 2007
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edited: 27.02.2024
Giant Mandarina Snail (Mandarina titan)
This species was described in 1989 based on fossil and subfossil material that had been collected from the fissure deposits of Minamijima Island, Ogasawara Islands, Japan. [1]
The Giant Mandarina Snail was indeed a giant, its shells reached sizes of up to nearly 7 to 8 cm in diameter, making it the largest land snail species of the Ogasawara Islands and also of Japan. [2]
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The species first appeared about 13000 BCE and finally disappeares from the deposits at around 8000 BCE in the early Holocene, it disappeared due to natural environmental changes. [1]
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References:
[1] Satoshi Chiba: Taxonomy and morphologic diversity of Mandarina (Pulmonata) in the Bonin Islands. Transactions and Proceedings – Palaeontological Society of Japan 155: 218-251. 1989
[2] Satoshi Chiba: Taxonomic revision of the fossil land snail species of the genus Mandarina in the Ogasawara Islands. Paleontological Research 11(4): 317-329. 2007
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edited: 19.04.2019
Pallas Mandarina (Mandarina pallasiana)
This species was described in 1850, it is known from subfossil specimens that were recovered from Holocene deposits at the Kominato Beach on southern Chichijima Island, Ogasawara Islands, Japan.
The shells are quite large, some are white and bear two to four brown bands, some are unicolored brown without bands. [1]
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The species was for some time thought to be identical with the Minamizaki Mandarina Snail. [1]
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The Pallas Mandarina died out because of natural climatic changes that lead to a rise of the temperatures making the habitat becoming dryer.
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References:
[1] Satoshi Chiba: Taxonomic revision of the fossil land snail species of the genus Mandarina in the Ogasawara Islands. Paleontological Research 11(4): 317-329. 2007
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edited: 19.04.2019