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| Siamochlamys panhai Pholyotha, Pholyotha, Tongkerd et Sutcharit, 2023. |
Abstract
A new genus and new species of helicarionid snail, Siamochlamys panhai, is described from limestone outcrops in Thailand. This new genus differs from all helicarionid genera based on morphological characters of shell, radula, and genitalia. The diagnostic characters of Siamochlamys panhai gen. et sp. nov. are depressed shell, well-polished surface, umbilicus opened, and aperture less covered by reflection of columellar margin. The genitalia exhibit a straight epiphallic caecum and small flagellum but lack a dart apparatus; radula has tricuspid central and lateral teeth and bicuspid marginal teeth. The discovery of this karst-associated land snail increases the knowledge of endemic malacofauna in Thailand, and also suggests that many taxa remain undiscovered.
Keywords: endemic, Indochina, land snail, limestones, taxonomy
Superfamily Helicarionoidea Bourguignat, 1877
Family Helicarionidae Bourguignat, 1877
Subfamily Durgellinae Godwin-Austen, 1888
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| Living snails and mantle extensions of Siamochlamys panhai gen. et sp. nov. paratype CUMZ14211. A. living snail during relaxed position showing the expansion of mantles B. alcohol-preserved snailshowingshell lobes and dorsal lobes and posterior body C. dorsal view of mantle extensions (shell lobes and dorsal lobes). |
Genus Siamochlamys Pholyotha gen. nov.
Etymology.− The name combines ‘Siam’,which is a former name of Thailand,chosen because this snail is restricted to the country as far as we know, and the Greek word ‘chlamys’,meaning “mantle or cloak”. Therefore, the generic name means the land snail with well-developed mantle extensions from Thailand.
Diagnosis.− Depressed, glossy shellwith open umbilicus, straight epiphallic caecum, short flagellum, no dart apparatus, radula with tricuspidcentral and lateral teeth and bicuspid marginal teeth, andfive mantle extensions well-developed.
Siamochlamys panhai Pholyotha, sp. nov.
Arthit Pholyotha, Piyoros Tongkerd, Chirasak Sutcharit. 2023. Siamochlamys panhai, A New Limestone Karst‐Restricted Terrestrial Snail from Thailand (Eupulmonata: Helicarionidae). Tropical Natural History. Supplement 7;41-50. DOI: doi.org/10.58837/tnh.23.7.258814
