[Mollusca • 2026] Pagodapalaina euphrosyne • A New open-coiled Microsnail Species of the Genus Pagodapalaina (Caenogastropoda: Diplommatinidae) from Thailand

Pagodapalaina euphrosyne Sutcharit,

 

in Sutcharit, Srisonchai, Maneewan, Jeratthitikul et Annate, 2026. 

หอยกระสวยจิ๋วคลายเกลียวยูโฟรซีน  |  DOI: doi.org/10.1556/1777.2026.00169  

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Abstract

A new species of Pagodapalaina from southern Thailand is described. Pagodapalaina euphrosyne Sutcharit, sp. nov. is characterised by a sinistral, elongate-fusiform shell with an open-coiled teleoconch, well-developed radial ribs restricted to the penultimate and last whorls, and the presence of the parietalis and columellaris. Unlike all other congeners, the detached teleoconch subsequently resumes regular coiling, with the last whorl becoming tightly reattached to the preceding whorl. This previously undocumented developmental pattern raises fundamental questions about current understanding of the developmental constraints governing shell coiling in terrestrial caenogastropods.

Keywords: limestone; endemic species; whorl detachment; ecophenotypic plasticity; micro-CT

A, approximate locations of the type locality of all Pagodapalaina species.
Numbers correspond to: 1) P. acme (Laidlaw, 1949) [= Diplommatina laemsonensis Boonmachai, Bergey & Nantarat, 2023]; 2) P. attenuata (Laidlaw, 1949); 3) P. carinaspinosa (Maassen, 2002); 4) P. diminuta (von Möllendorff, 1891); 5) Pagodapalaina euphrosyne sp. nov.; 6) P. gadutensis (Maassen, 2002); 7) P. hidagai (Panha, 1998a); 8) P. hortulanica Chen, 2025; 9) P. jirasaki (Panha, Kanchanasaka & Burch, 2002); 10) P. karoensis (Maassen, 2002); 11) P. krabiensis (Panha & Burch, 1998); 12) P. lenggongensis (Tomlin, 1941) [= Diplommatina lenggongensis nawawii Davison, 1995]; 13) P. parabates (Laidlaw, 1949); 14) P. pongrati (Panha, Kanchanasaka & Burch, 2002); 15) P. prakayangensis (Panha, 1998b); 16) P. sinistra (Tomlin, 1938) [= Diplommatina prakaiphetensis Boonmachai, Bergey & Nantarat, 2023]; 17.1) P. superba superba (Godwin-Austen & Nevill, 1879); 17.2) P. superba brevior (Laidlaw, 1949); 18) P. suratensis (Panha & Burch, 1998);
B, live snail of  Pagodapalaina euphrosyne sp. nov.

Systematics

Superfamily Cyclophoroidea Gray, 1847

Family Diplommatinidae Pfeiffer, 1856

Genus Pagodapalaina Chen, 2025

Pagodapalaina Chen in Chen et al. 2025: 390, 391.

Type species: Diplommatina acme Laidlaw, 1949, by original designation.

Remark: The genus is characterised by a sinistrally coiled, elongate-fusiform shell with tightly to loosely coiled whorls and a shell surface bearing low ridges to prominent and trough-like radial ribs. The internal lamellar system comprises a well-developed columellaris, a parietalis varying from small to well developed, a vertical palatalis that may be absent, and a constriction ranging from weak to strong.

The genus currently comprises 18 recognised species (Chen et al. 2025, MolluscaBase 2026, this study). Of these, three species are known from Sumatra, Indonesia, and nine species, including the new species described herein, are recorded from Thailand. The northern distributional limit of the genus is currently considered not to extend beyond the Isthmus of Kra (Fig. 1A).

Pagodapalaina euphrosyne sp. nov., paratypes CUMZ 14506 from the type locality.
A, B, adult specimens with narrowly expanded lip;
C, juvenile specimen shows an early stage of penultimate whorl, and onset of tall trough-like radial ribs

Pagodapalaina euphrosyne sp. nov. from the type locality.
A, holotype CUMZ 14505, insets show the aperture with columellaris;
B, paratype CUMZ 14506, juvenile with penultimate and last whorl reattached but lip not yet expanded;
C, paratype CUMZ 14506, insets show the protoconch sculpture

Pagodapalaina euphrosyne Sutcharit, sp. nov.

Diagnosis: Shell small, sinistral, elongate-conical, fusiform, with ∼6 whorls. Earlier teleoconch whorls solute for about two whorls, with smooth surface. Penultimate and last whorls regularly coiled, tightly attached, sculptured with very tall, trough-like radial ribs, and fine spiral striations throughout. Peristome double, expanded. Aperture rounded, with four barriers: one parietalis, two vertical palatalis and one columellaris.

Etymology: The specific epithet, euphrosyne, is a noun in apposition derived from Euphrosyne, one of the Three Graces (Charites) in Greek mythology, the personification of joy, beauty, and elegance. It refers to the graceful and delicate shell morphology of the new species.

  Chirasak Sutcharit, Ruttapon Srisonchai, Nattaphong Maneewan, Ekgachai Jeratthitikul and Supunya Annate. 2026. A New open-coiled Microsnail Species of the Genus Pagodapalaina (Caenogastropoda: Diplommatinidae) from Thailand. Animal Taxonomy and Ecology. DOI: doi.org/10.1556/1777.2026.00169 [16 Sep 2026]

𝙋𝙖𝙜𝙤𝙙𝙖𝙥𝙖𝙡𝙖𝙞𝙣𝙖 𝙚𝙪𝙥𝙝𝙧𝙤𝙨𝙮𝙣𝙚 Sutcharit, 2026 หรือ หอยกระสวยจิ๋วคลายเกลียวยูโฟรซีน ค้นพบที่ถ้ำทะลุ อำเภอละงู จังหวัดสตูล โดยตั้งชื่อชนิดตามรูปร่างเปลือกที่ละเอียดอ่อนและสง่างาม เสมือน “ยูโฟรซีน” ผู้เป็น 1ใน 3เทพีแห่งความงามของเทพปกรณัมกรีก 

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[Mollusca • 2025] Pagodapalaina gen. nov. & Pagodapalaina hortulanica • A New sinistral Genus of Diplommatinidae (Gastropoda: Cyclophoroidea) from the Malay Peninsula and Sumatra, with Description of A New Species from Perak, Peninsular Malaysia

Pagodapalaina Z.-Y. Chen gen. nov.
Pagodapalaina hortulanica gen. & sp. nov.
 Pagodapalaina spp. 

in Chen, Sutcharit et Ablett, 2025.

DOI: doi.org/10.11646/zootaxa.5737.3.5  

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Abstract

A new diplommatinid genus, Pagodapalaina Z.-Y. Chen gen. nov., is erected for several sinistral species from the Malay Peninsula and Sumatra originally assigned to Diplommatina Benson, 1849. In addition, a new species of this new genus, Pagodapalaina hortulanica sp. nov., is described from Perak, Peninsular Malaysia. The genus Pagodapalaina gen. nov., is characterised by a sinistral and conical shell with a mostly keeled periphery; the radula consists of a strong central tooth with a large central cusp and smaller lateral cusps; the basal plate of the central tooth bears two small cusps; the lateral and marginal teeth have very short basal parts. An annotated type catalogue of all known species is presented, with illustrations provided for most taxa. Additionally, Diplommatina laemsonensis Boonmachai, Bergey & Nantarat, 2023 and Diplommatina prakaiphetensis Boonmachai, Bergey & Nantarat, 2023 are recognised as synonyms of Pagodapalaina acme (Laidlaw, 1949) comb. nov., and Pagodapalaina sinistra (Tomlin, 1938) comb. nov., respectively.

Mollusca, Micro snails, new genus, new species, Southeast Asia, systematics, taxonomy

Pagodapalaina hortulanica gen. & sp. nov., holotype, NHMUK 19930124.

Pagodapalaina Z.-Y. Chen gen. nov.

Etymology. The name of the new genus is derived from “Pagoda”, referring to the tiered, keeled and tower-like shape of the shell, reminiscent of East Asian pagodas, and diplommatinid genus name Palaina . This genus name is feminine.

Distribution. Thailand, Malaysia, Indonesia. The known species of the new genus are distributed on the Malay Peninsula and Sumatra.

Pagodapalaina hortulanica sp. nov.

Etymology. We adopted Davison’s manuscript name with minor modification. The name hortulanica, meaning “garden-dwelling” in Latin, may refer to the flourishing vegetation of the type locality.

 Pagodapalaina spp. 

FIG. 3. A. Pagodapalaina lenggongensis, syntype, NHMUK 1943.6.28.1. B. Pagodapalaina hidagai, paratype, CUMZ Di 005. C. Pagodapalaina parabates, holotype, NHMUK 1948.11.12.6. D. Pagodapalaina pongrati, paratype, CUMZ Di 044. E. Pagodapalaina prakayangensis, paratype, CUMZ Di 007. F. Pagodapalaina sinistra, syntype, NHMUK 1938.10.25.4. G. Pagodapalaina superba brevior, holotype, NHMUK 1948.11.12.7, the outline of shell follows Laidlaw (1949). H. Pagodapalaina suratensis, paratype CUMZ Di 029. Scale bars = 1 mm.

FIG. 2. A. Pagodapalaina acme, holotype, NHMUK 1948.11.12.5. B. Pagodapalaina attenuate, holotype, NHMUK 1948.11.12.8. C. Pagodapalaina carinaspinosa, paratype, NHMUK 20030224/1. D. Pagodapalaina diminuta, holotype, SMF 105374/1. E. Pagodapalaina gadutensis, paratype, NHMUK 20030225/1. F. Pagodapalaina jirasaki, paratype, CUMZ Di 041. G. Pagodapalaina karoensis, paratype, NHMUK 20030226/1. H. Pagodapalaina krabiensis, paratype CUMZ Di 032. Scale bars = 1 mm.

ZHE-YU CHEN, CHIRASAK SUTCHARIT, JONATHAN D. ABLETT. 2025. Pagodapalaina, A New sinistral Genus of Diplommatinidae from the Malay Peninsula and Sumatra, with Description of A New Species from Perak, Peninsular Malaysia (Gastropoda: Caenogastropoda: Cyclophoroidea). Zootaxa. 5737(3); 389-400. DOI: doi.org/10.11646/zootaxa.5737.3.5 [2025-12-24]

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[Mollusca • 2025] An illustrated Type Catalogue of Diplommatina Benson, 1849 from mainland China, with description of A New Species, Diplommatina yipingica (Gastropoda: Cyclophoroidea)

Diplommatina yipingica Zhang,

in Xie, Zhang, Meng et Köhler, 2025. 

DOI: doi.org/10.3897/zse.101.133434 

Abstract 

We document type material of 41 nominal species from mainland China that were originally assigned to Diplommatina. This catalogue is based on inspection of the Heude Type collection in the National Zoological Museum of China, Beijing and complemented with information on types held by other international museums from a comprehensive literature review. We designate lectotypes of five nominal species, Diplommatina abbreviata Heude, 1890, D. confusa Heude, 1885, D. intermedia Heude, 1890, D. minuscula Heude, 1890, D. pupinella Heude, 1885 and D. pyra Heude, 1885.

In addition, a new species, Diplommatina yipingica Zhang, sp. nov., is described from Qingdao City, Shandong Province. A new name, D. yunnanensis, is introduced for Diplommatina minuscula Chen & Zhang, 1998, which is a junior homonym of D. minuscula Heude, 1890.

Key Words: Diplommatinidae, nomenclature, Shandong Province, Sinica, type material

Type material of Diplommatina yipingica Zhang, sp. nov.
A–F. Holotype of D. yipingica in apex, umbilicus, lateral, aperture and dorsal views. G. Palatalis and parietalis of new species; F. Columellaris of new species.

 

Living specimens of Diplommatina yipingica Zhang.

Diagnosis. Penultimate slightly expanded, body whorl nearly equal in width. Shell with one palatalis and three parietalis. Prt1 shorter than Prt 2.

Etymology. The name is derived from the Chinese word yiping [= yishengpingan], which means a fully peaceful and safe life.

Guang-Long Xie, Guoyi Zhang, Kaibaryer Meng, Frank Köhler. 2025. An illustrated type catalogue of Diplommatina Benson, 1849 from mainland China, with description of A New Species, Diplommatina yipingica (Gastropoda, Cyclophoroidea). Zoosystematics and Evolution. 101(2): 551-570. DOI: doi.org/10.3897/zse.101.133434 

[Mollusca • 2020] Diplommatina fusiformis, D. burapha, ... • A Review of Diplommatina Species (Gastropoda: Diplommatinidae) in eastern Thailand with the Descriptions of Five New Species

[A] Diplommatina fusiformis spec. nov. หอยกระสวยจิ๋ว,  

[B-E] D. khwantongae spec. nov. หอยกระสวยจิ๋วคณิตา, 

D. crispata khaochamaoensis Panha et al., 1998, 

  หอยกระสวยจิ๋วบูรพา D. burapha sp. n.,   

หอยกระสวยจิ๋วชฎาทอง D. chadathongae Kamtuptim, Dumrongrojwattana & Wongkamhaeng sp. nov.  

หอยกระสวยจิ๋วจันทบุรี  D. chantaburiensis sp. n. 

 in Dumrongrojwattana, Kamtuptim & Wongkamhaeng, 2020

 DOI: 10.3897/BDJ.8.e57689

Abstract

Background: Microsnails in the genus Diplommatina Benson, 1849 from eastern Thailand are revised, based on the collection of the Zoological Research Collection, Burapha University, Chonburi Province, Thailand and on recently-collected materials.

New information: Five new species, Diplommatina burapha sp. n., D. chadathongae sp. n., D. chantaburiensis sp. n., D. fusiformis sp. n. and D. khwantongae sp. n., are described as new to science. The geographic distribution of these eastern species is presented.

Keywords: Diplommatina, Diplommatinidae, taxonomy, Thailand

Four Diplommatina species from eastern Thailand. 
A) Diplommatina crispata khaochamaoensis Panha et al., 1998, B) D. burapha sp. n.,
C) D. chadathongae sp. nov. and D) D. chantaburiensis sp. n. 

Each species shows a frontal view, lateral view, dorsal view and the number of ribs per 0.5 mm on the penultimate whorl and body whorl, respectively.

Two Diplommatina species from eastern Thailand.
A) D. fusiformis spec. nov., B-E) D. khwantongae spec. nov.,
B) Holotype, C-D) Living snail. (Photos by Ms. Rattanawadee Tekavong).
Each species shows a frontal view, lateral view, dorsal view and the number of ribs per 0.5 mm on the penultimate whorl and body whorl, respectively.

  

 Pongrat Dumrongrojwattana, Chanakarn Kamtuptim and Koraon Wongkamhaeng. 2020. A Review of Diplommatina Species in eastern Thailand with the Descriptions of Five New Species. Biodiversity Data Journal. 8: e57689. DOI: 10.3897/BDJ.8.e57689

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 สด ๆ ร้อน ๆ หอยกระสวยจิ๋วชนิดใหม่ของโลก 5 ชนิด จากภาคตะวันออก ได้แก่ 

1. หอยกระสวยจิ๋วบูรพา (Diplommatina burapha Dumrongrojwattana, Kamtuptim & Wongkamhaeng, 2020) จากจังหวัดสระแก้ว ตั้งตามภูมิภาคที่พบ คือ ภาคตะวันออกและสอดคล้องกับชื่อมหาวิทยาลัย "บูรพา"

2. หอยกระสวยจิ๋วชฎาทอง (Diplommatina chadathongae Kamtuptim et al., 2020 in Dumrongrojwattana et al., 2020) หอยชนิดนี้ตั้งชื่อเพื่อเป็นเกียรติและระลึกถึงคุณแม่ของนางสาวชนากานต์ ขำทับทิม นิสิตชั้นปีที่ 4 ภาควิชาชีววิทยา หนึ่งในผู้ร่วมงานวิจัยชิ้นนี้

3. หอยกระสวยจิ๋วจันทบุรี (Diplommatina chantaburiensis Dumrongrojwattana et al., 2020) ตั้งชื่อตามจังหวัดจันทบุรี ที่ซึ่งพบหอยกระสวยจิ๋วชนิดนี้เป็นครั้งแรก

4. หอยกระสวยจิ๋ว (Diplommatina fusiformis Dumrongrojwattana et al., 2020) ตั้งชื่อตามรูปทรงเปลือกหอยที่เป็นทรงกระสวย

5. หอยกระสวยจิ๋วคณิตา (Diplommatina khwantongae Dumrongrojwattana et al., 2020) ตั้งชื่อให้เป็นเกียรติและแสดงความระลึกถึง นางสาวคณิตา ขวานทอง หรือ พะลอย ของอาจารย์และเพื่อน ๆ ร่วมรุ่น นิสิตผู้ทำการศึกษาและค้นพบหอยกระสวยจิ๋วชนิดนี้ ผู้จากไปก่อนวัยอันควร

ผลการศึกษาครั้งนี้ ทำให้จำนวนชนิดของหอยกระสวยจิ๋วในภาคตะวันออก เพิ่มขึ้นจากเดิมที่รายงานไว้เพียง 1 ชนิด คือ หอยกระสวยจิ๋วเขาชะเมา (Diplommatina crispata khaochamaoensis) เพิ่มขึ้นเป็น 6 ชนิด

[Mollusca • 2023] Opisthostoma platyconcha & O. somsakpanhai • Two New Species of Opisthostoma (Caenogastropoda: Diplommatinidae) from Southern Thailand

Opisthostoma somsakpanhai

Dumrongrojwattana, Jaroonpongsawat & Tekavong, 2023

 Tropil History. Supplement 7

tci-thaijo.org/index.php/TNH

Abstract

Opisthostoma platyconcha sp. nov. and Opisthostoma somsakpanhai sp. nov. are described from limestone hills in the South of Thailand. These new species can be distinguished from their congeners by prominent shell characters: shape, number of radial ribs per 0.5 millimeters, and distinct constriction. This is the first report of Opisthostoma species in Phatthalung and Chumphon provinces; there are now three species of this genus in Thailand.

Keywords: diversity, leaf litter, limestone, microsnail, Prosobranchia

Opisthostoma somsakpanhai sp. nov.
A.–E. Holotype ZRCBUU0789: A. left lateral view, B. top view, C. Protoconch with spiral striae, D. straight radial ribs on the penultimate whorl, and E. slightly curved radial ribs on the body whorl.
 F.–H. Paratype ZRCBUU 0796: F.left lateral view, G. right lateral view, and H. bottom view.
I., J. O. somsakpanhai sp. nov. in natural habitat.

Scale bar = 0.5 mm.

Pongrat Dumrongrojwattana, Saruttaya Jaroonpongsawat and Rattanawadee Tekavong. 2023. Two New Species of Opisthostoma (Caenogastropoda: Diplommatinidae) from Southern Thailand. Tropical Natural History. Supplement 7; 181-186

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[Mollusca • 2023] Diplommatina bulonensis, D. laemsonensis & D. prakaiphetensis • Three New Species of the Land Snail of the Genus Diplommatina Benson, 1849 (Caenogastropoda: Diplommatinidae) from Satun Province, Thailand

Diplommatina bulonensis, D. laemsonensis & D. prakaiphetensis 

 Boonmachai, Bergey & Nantarat, 2023

DOI: 10.3897/zse.99.99030  

Abstract

The micro land snail genus Diplommatina (family Diplommatinidae) is widely distributed in Southeast Asia and includes many endemic species. Three new species of Diplommatina are described from Satun Province in southern Thailand. Diplommatina bulonensis sp. nov., D. laemsonensis sp. nov. and D. prakaiphetensis sp. nov. are distinguished from other species in the genus by their shell size and shape, the number of radial ribs on the penultimate whorl, the number of whorls, and features of the peristome. The agreement between phylogenetic tree based on analyses of COI and 16S sequences and comparative morphology support the delineation of these new species which, when compared to related species, belong to well-differentiated clades. The K2P distance between any of the three new species and other Diplommatina species included in the molecular phylogenetic analysis was at least 5.5% in COI and 3.9% in 16S. Two of the three new species (D. prakaiphetensis sp. nov. and D. bulonensis sp. nov.) are apparently endemic to Prakaiphet Hill and Bulon Pai Island, respectively. Additionally, we documented a new regional record for D. naiyanetri in Satun Province. These new species and records contribute to the knowledge of Thailand’s land snail biodiversity and highlight the need of conservation protections for regional karst habitats.

Key Words: endemic, limestone, micro land snail, phylogeny, taxonomy

Localities of micro land snail sampling in Satun Province, Thailand.
A. Bulon Pai Island; B. Talutao Island; C. Khao Yai Island; D. Laem Son Hill; E. Prakaiphet Hill; F. Tharn Pliew Waterfall; G. Phu Pha Phet Cave.

The symbols without letters show previous records for different species of Diplommatina that are known from Thailand (Maassen 2001b; Panha and Burch 2005; Tongkerd et al. 2013; Inkhavilay et al. 2019; Dumrongrojwattana et al. 2020).

Shell internal terminology of new species of the genus Diplommatina from Satun Province
under the stereo microscope and the drawing.
A, B. D. bulonensis sp. nov. (Bulon Pai Island);
C, D. D. laemsonensis sp. nov. (Laem Son Hill);
E, F. D. prakaiphetensis sp. nov. (Prakaiphet Hill).

Shell morphology of Diplommatina from Satun Province.
A. D. bulonensis sp. nov. (Holotype CMUZ 9050001; Bulon Pai Island);
B. D. laemsonensis sp. nov. (Holotype CMUZ 9050019; Laem Son Hill);
C. D. prakaiphetensis sp. nov.  (Holotype CMUZ 9050066; Prakaiphet Hill);
D. D. naiyanetri (CMUZ 905090; Tarutao Island);
E. D. canaliculata (CMUZ 9050158; Tharn Pliew Waterfall).

 Tuangthong Boonmachai, Elizabeth A. Bergey and Nattawadee Nantarat. 2023. First Record and Description of Three New Species in the Land Snail Genus Diplommatina Benson, 1849 (Caenogastropoda, Diplommatinidae) from Satun Province, Thailand. Zoosystematics and Evolution. 99(1): 195-207. DOI: 10.3897/zse.99.99030