taxonID	type	description	language	source
038F879A7A48C63AFCD3FBA6FBA7D86F.taxon	type_taxon	Type species. Alycaeus (Chamalycaeus) fruhstorferi von Möllendorff, 1897 [Páll-Gergely et al., 2020: fig. 6 b] by monotypy.	en	Jirapatrasilp, Parin, Thi, Sothearen, Chantha, Nasak, Chourn, Phyroum, Sophea, Chhin, Jeratthitikul, Ekgachai, Pholyotha, Arthit, Siriwut, Warut, Srisonchai, Ruttapon, Panha, Somsak, Sutcharit, Chirasak (2025): The first record of an operculate micro land snail from the Alycaeinae (Caenogastropoda, Cyclophoridae) in Cambodia, with description of a new species of Chamalycaeus von Möllendorff, 1897. Ruthenica, Russian Malacological Journal 35 (2): 65-72, DOI: 10.35885/ruthenica.2025.35(2).2, URL: https://doi.org/10.35885/ruthenica.2025.35(2).2
038F879A7A48C63AFCD3FBA6FBA7D86F.taxon	discussion	Remarks: This genus is diagnosed by having a spirally-striated teleoconch, a protoconch without spiral striae, and a wide umbilicus. At present, there is a total of 31 species and two subspecies of Chamalycaeus known from the southeastern Himalaya Region, Myanmar, Thailand, down to the Malay Peninsula, Sumatra, Java, Borneo, Sulawesi, including the Philippine Palawan Island [Páll-Gergely et al., 2020, 2021; Vermeulen, Liew, 2022]. See Páll-Gergely et al. [2020] for extended diagnosis and taxonomic remarks.	en	Jirapatrasilp, Parin, Thi, Sothearen, Chantha, Nasak, Chourn, Phyroum, Sophea, Chhin, Jeratthitikul, Ekgachai, Pholyotha, Arthit, Siriwut, Warut, Srisonchai, Ruttapon, Panha, Somsak, Sutcharit, Chirasak (2025): The first record of an operculate micro land snail from the Alycaeinae (Caenogastropoda, Cyclophoridae) in Cambodia, with description of a new species of Chamalycaeus von Möllendorff, 1897. Ruthenica, Russian Malacological Journal 35 (2): 65-72, DOI: 10.35885/ruthenica.2025.35(2).2, URL: https://doi.org/10.35885/ruthenica.2025.35(2).2
038F879A7A48C638FC3BF8B8FB1EDA3D.taxon	description	(Figs 1 – 3) Zoobank registration: urn: lsid: zoobank. org: act: 068 B 2 DC 0 - BC 09 - 4 BA 7 - 80 B 0 - E 8592 A 1 D 88 FD	en	Jirapatrasilp, Parin, Thi, Sothearen, Chantha, Nasak, Chourn, Phyroum, Sophea, Chhin, Jeratthitikul, Ekgachai, Pholyotha, Arthit, Siriwut, Warut, Srisonchai, Ruttapon, Panha, Somsak, Sutcharit, Chirasak (2025): The first record of an operculate micro land snail from the Alycaeinae (Caenogastropoda, Cyclophoridae) in Cambodia, with description of a new species of Chamalycaeus von Möllendorff, 1897. Ruthenica, Russian Malacological Journal 35 (2): 65-72, DOI: 10.35885/ruthenica.2025.35(2).2, URL: https://doi.org/10.35885/ruthenica.2025.35(2).2
038F879A7A48C638FC3BF8B8FB1EDA3D.taxon	materials_examined	Type material: Holotype CUMZ 14461 (Fig. 1), paratypes CUMZ 14462 (25 shells; Fig. 2), NHMUK 20250001 (3 shells) and SMF 380296 (3 shells) from Locality C 110, Temple in Kantueu Pir (Kantueu Hill), Banan, Battambang, Cambodia, 12 ° 54 ’ 15.7 ” N, 103 ° 07 ’ 13.1 ” E (Fig. 3), 2 Aug 2024, coll. W. Siriwut, C. Sutcharit.	en	Jirapatrasilp, Parin, Thi, Sothearen, Chantha, Nasak, Chourn, Phyroum, Sophea, Chhin, Jeratthitikul, Ekgachai, Pholyotha, Arthit, Siriwut, Warut, Srisonchai, Ruttapon, Panha, Somsak, Sutcharit, Chirasak (2025): The first record of an operculate micro land snail from the Alycaeinae (Caenogastropoda, Cyclophoridae) in Cambodia, with description of a new species of Chamalycaeus von Möllendorff, 1897. Ruthenica, Russian Malacological Journal 35 (2): 65-72, DOI: 10.35885/ruthenica.2025.35(2).2, URL: https://doi.org/10.35885/ruthenica.2025.35(2).2
038F879A7A48C638FC3BF8B8FB1EDA3D.taxon	diagnosis	Diagnosis: SH up to 2.0 mm, SW up to 2.7 mm, depressed-conical. Spire ca. 1 / 4 of shell height. Spiral striation with 11 – 13 spiral striae at apical view. R 1 ca. 1 ¼ whorls with regular ribs; R 2 ca. 1 / 5 whorl and nearly as long as R 3; R 2 with ca. 22 ribs. R 3 strongly coils downwards, being highly oblique to the shell’s horizontal axis, expanding near the end of the aperture. Aperture round. Inner peristome sharp, protruding. Outer peristome thickened, multilayered expanded; palatal to basal edge expanded, columellar to parietal edge not expanded, basal edge triangular and bending inwards, appearing beak- or hook-like. Umbilicus round.	en	Jirapatrasilp, Parin, Thi, Sothearen, Chantha, Nasak, Chourn, Phyroum, Sophea, Chhin, Jeratthitikul, Ekgachai, Pholyotha, Arthit, Siriwut, Warut, Srisonchai, Ruttapon, Panha, Somsak, Sutcharit, Chirasak (2025): The first record of an operculate micro land snail from the Alycaeinae (Caenogastropoda, Cyclophoridae) in Cambodia, with description of a new species of Chamalycaeus von Möllendorff, 1897. Ruthenica, Russian Malacological Journal 35 (2): 65-72, DOI: 10.35885/ruthenica.2025.35(2).2, URL: https://doi.org/10.35885/ruthenica.2025.35(2).2
038F879A7A48C638FC3BF8B8FB1EDA3D.taxon	description	Description: SH up to 2.0 mm, SW up to 2.7 mm, depressed-conical, solid, translucent, yellowish to pale crimson. Shell outline oval in apical view, spire ca. 1 / 4 of shell height. Whorls ca. 3 ¾ – 4. Protoconch low, ca. two whorls, glossy, smooth, without spiral striation. Spiral striation starts from R 1, continuing to the end of aperture, with 11 – 13 spiral striae at apical view, spiral striation weaker than radial ribs in R 1 and R 2. R 1 ca. 1 ¼ whorls, with fine, regular ribs; with ca. 13 ribs in ¼ whorl adjoining R 2. Boundary between R 1 and R 2 distinct as R 2 contains more close-set and thicker ribs than R 1; R 2 with ca. 22 ribs that are curved towards aperture, ribs less thickened at the beginning and the end of R 2; R 2 ca. 1 / 5 whorl and nearly as long as R 3. Boundary between R 2 and R 3 distinct due to very shallow constriction; R 3 with indistinct growth lines, strongly coils downwards being highly oblique to the shell’s horizontal axis, expanding near the end of the aperture. Last whorl with bluntly shouldered and ended around the beginning of R 3. Aperture round; opening obliquely downwards. Peristome double with prominent outer peristome. Inner peristome sharp, protruding. Outer peristome thickened, multilayered (visible in lateral view); palatal to basal edge expanded, columellar to parietal edge not expanded, basal edge triangular and bending inwards, appearing beak- or hook-like. Umbilicus round, open, approximately one third of shell width, and with weakly blunt-periumbilical ridge that ended around the beginning of R 3. Operculum unknown.	en	Jirapatrasilp, Parin, Thi, Sothearen, Chantha, Nasak, Chourn, Phyroum, Sophea, Chhin, Jeratthitikul, Ekgachai, Pholyotha, Arthit, Siriwut, Warut, Srisonchai, Ruttapon, Panha, Somsak, Sutcharit, Chirasak (2025): The first record of an operculate micro land snail from the Alycaeinae (Caenogastropoda, Cyclophoridae) in Cambodia, with description of a new species of Chamalycaeus von Möllendorff, 1897. Ruthenica, Russian Malacological Journal 35 (2): 65-72, DOI: 10.35885/ruthenica.2025.35(2).2, URL: https://doi.org/10.35885/ruthenica.2025.35(2).2
038F879A7A48C638FC3BF8B8FB1EDA3D.taxon	etymology	Etymology: The specific epithet is derived from the Latin word ‘ uncus’ meaning ‘ hook, barb or bent’. The epithet aduncus refers to the basal edge of the outer lip bending inwards and appearing beak- or hook-like.	en	Jirapatrasilp, Parin, Thi, Sothearen, Chantha, Nasak, Chourn, Phyroum, Sophea, Chhin, Jeratthitikul, Ekgachai, Pholyotha, Arthit, Siriwut, Warut, Srisonchai, Ruttapon, Panha, Somsak, Sutcharit, Chirasak (2025): The first record of an operculate micro land snail from the Alycaeinae (Caenogastropoda, Cyclophoridae) in Cambodia, with description of a new species of Chamalycaeus von Möllendorff, 1897. Ruthenica, Russian Malacological Journal 35 (2): 65-72, DOI: 10.35885/ruthenica.2025.35(2).2, URL: https://doi.org/10.35885/ruthenica.2025.35(2).2
038F879A7A48C638FC3BF8B8FB1EDA3D.taxon	distribution	Distribution and habitat: Known only from the type locality in Kantueu Hill, Battambang, Cambodia. The Kantueu Hill is an isolated limestone outcrop located south of Battambang town. The hill is about 400 m wide and surrounded by agricultural areas and temple buildings. The vegetation of this hill is a deciduous forest with moderate disturbance by clear- ing or mowing of low vegetation and with evidence of fire. The specimens examined herein are empty shells, which were collected from the topsoil under the leaf litter near rock base or crevices.	en	Jirapatrasilp, Parin, Thi, Sothearen, Chantha, Nasak, Chourn, Phyroum, Sophea, Chhin, Jeratthitikul, Ekgachai, Pholyotha, Arthit, Siriwut, Warut, Srisonchai, Ruttapon, Panha, Somsak, Sutcharit, Chirasak (2025): The first record of an operculate micro land snail from the Alycaeinae (Caenogastropoda, Cyclophoridae) in Cambodia, with description of a new species of Chamalycaeus von Möllendorff, 1897. Ruthenica, Russian Malacological Journal 35 (2): 65-72, DOI: 10.35885/ruthenica.2025.35(2).2, URL: https://doi.org/10.35885/ruthenica.2025.35(2).2
038F879A7A48C638FC3BF8B8FB1EDA3D.taxon	discussion	Remarks: Among all Chamalycaeus species, there are only three taxa where the R 3 strongly coils downwards, being highly oblique to the shell’s horizontal axis. They are Chamalycaeus aduncus sp. nov., C. excisus excisus (von Möllendorff, 1887) and C. excisus sublimus Páll-Gergely et Auffenberg, 2019; the latter two being from the Philippines [Páll-Gergely, Auffenberg, 2019]. These three species are also similar in shell size and depressed-conical shell shape. However, this new species differs from both C. excisus excisus and C. excisus sublimus in having a shorter R 2 without any blunt keel, a round aperture without any incision, and a beak- or hook-like basal edge of the outer peristome (Fig. 1 B). The aperture of Chamalycaeus aduncus sp. nov. is also similar to C. serratus Páll-Gergely et Auffenberg, 2021 and C. krabiensis Páll-Gergely et A. Reischütz, 2021 from Thailand [Páll-Gergely et al., 2021]. However, the basal edge of the outer peristome in this new species is triangular and highly bending inwards, appearing beak- or hook-like. Moreover, the new species has a shorter R 2 with less ribs, and a more bluntly shouldered last whorl. Five shells out of the 32 examined specimens had a scraping hole. It is possible that these specimens were predated by the carnivorous micro land snail Diaphera saurini Benthem Jutting, 1962, as they were found abundant at this locality.	en	Jirapatrasilp, Parin, Thi, Sothearen, Chantha, Nasak, Chourn, Phyroum, Sophea, Chhin, Jeratthitikul, Ekgachai, Pholyotha, Arthit, Siriwut, Warut, Srisonchai, Ruttapon, Panha, Somsak, Sutcharit, Chirasak (2025): The first record of an operculate micro land snail from the Alycaeinae (Caenogastropoda, Cyclophoridae) in Cambodia, with description of a new species of Chamalycaeus von Möllendorff, 1897. Ruthenica, Russian Malacological Journal 35 (2): 65-72, DOI: 10.35885/ruthenica.2025.35(2).2, URL: https://doi.org/10.35885/ruthenica.2025.35(2).2
