taxonID	type	description	language	source
095F7E0C6B705DEC8E9EF734D112E162.taxon	description	Figs 2 A, B, 3 A – I, 5 A – E, 6 A, B; Table 2	en	Tanmuangpak, Kitti, Nahok, Benchawan, Chanlabut, Utain, Tumpeesuwan, Chanidaporn, Tumpeesuwan, Sakboworn (2025): Two new species of terrestrial microsnails of the genus Hypselostoma W. H. Benson, 1856 (Gastropoda, Eupulmonata, Hypselostomatidae) from northeastern Thailand. ZooKeys 1265: 49-67, DOI: 10.3897/zookeys.1265.160661
095F7E0C6B705DEC8E9EF734D112E162.taxon	description	Measurements. Holotype: SH = 4.48 mm, SW = 3.34 mm, AH = 1.95 mm, AW = 1.92 mm. Paratypes (19 specimens measured): SH = 4.48 – 6.02 mm (5.58 ± 0.42 mm), SW = 3.07 – 4.12 mm (3.72 ± 0.36 mm), AH = 1.95 – 2.64 mm (2.24 ± 0.20 mm), AW = 1.68 – 2.42 mm (1.99 ± 0.16 mm) (Fig. 7).	en	Tanmuangpak, Kitti, Nahok, Benchawan, Chanlabut, Utain, Tumpeesuwan, Chanidaporn, Tumpeesuwan, Sakboworn (2025): Two new species of terrestrial microsnails of the genus Hypselostoma W. H. Benson, 1856 (Gastropoda, Eupulmonata, Hypselostomatidae) from northeastern Thailand. ZooKeys 1265: 49-67, DOI: 10.3897/zookeys.1265.160661
095F7E0C6B705DEC8E9EF734D112E162.taxon	diagnosis	Diagnosis. This new species has a prominent keel on the upper part of the last whorl and a weaker keel on the lower part. Apertural barriers absent (Fig. 3 A, G, H, L). Terminal part of the last whorl is adnated to penultimate whorl.	en	Tanmuangpak, Kitti, Nahok, Benchawan, Chanlabut, Utain, Tumpeesuwan, Chanidaporn, Tumpeesuwan, Sakboworn (2025): Two new species of terrestrial microsnails of the genus Hypselostoma W. H. Benson, 1856 (Gastropoda, Eupulmonata, Hypselostomatidae) from northeastern Thailand. ZooKeys 1265: 49-67, DOI: 10.3897/zookeys.1265.160661
095F7E0C6B705DEC8E9EF734D112E162.taxon	description	Description. Shell (Fig. 3 A – I) concave-conical, high spired, with 4 ¾ whorls. Large size for the genus, with shell height 4.48 – 6.02 mm, shell width 3.07 – 4.12 mm. The suture is deep. Protoconch smooth, with 1 – 1 ½ whorls that gradually increase in size to the teleoconch whorls. Teleoconch with 3 – 3 ¾ whorls, very fine spiral striation the body whorl widest, possesses two keels (upper one more prominent than the lower one). Apertural barriers absent. Peristome thickened and expanded. The parietal and convex angulo-palatal embayments form a sinulus, thickened, and expanded. The basal peristome is smooth and expanded, columellar side is more expand than the angulo-palatal side. Genital system (Fig. 6 A, B). Atrium shorter than the vagina. Penis shorter than the epiphallus, its anterior portion is a short and bulged tube, and the distal end of the penis bulge. Epiphallus connects to the distal end of the penis, shorter than vas deferens, anterior portion slender and cylindrical, its central portion more slender than the anterior portion, posterior portion curved, white glossy. Penial retractor muscle absent. Vas deferens long, slender, entering the epiphallus apically. The vagina and free oviduct are cylindrical, and the vagina is shorter than the free oviduct. The gametolytic sac is a long tube, with a swollen proximal part, and larger than penis, surrounded by a thin sheath and connected to the proximal part of the vagina, whose distal end is long, slender, and curved. Uterus large, with very thin prostate gland attached to it. Hermaphroditic duct loosely convoluted. The albumen gland large and yellowish. Dart apparatus absent. Radula (n = 4) (Fig. 5 A – E). Radula comprises 173 – 184 (179 ± 4.93) transverse rows of teeth each row containing 25 – 27 teeth. Radula formula (7 - 8) + 5 + 1 + 5 + (7 - 8). Central tooth small, unicuspid, elongated triangular. Lateral teeth bicuspid and asymmetrical, consisting of a large lanceolate endocone and smaller elongated triangular ectocone. Five lateral teeth on each side of the central tooth, the first tooth largest, and gradually smaller outwards. Marginal teeth start at 6 th tooth outwards from central teeth, which almost changed to tricuspids. On each outer side of the lateral teeth there are seven or eight marginal teeth.	en	Tanmuangpak, Kitti, Nahok, Benchawan, Chanlabut, Utain, Tumpeesuwan, Chanidaporn, Tumpeesuwan, Sakboworn (2025): Two new species of terrestrial microsnails of the genus Hypselostoma W. H. Benson, 1856 (Gastropoda, Eupulmonata, Hypselostomatidae) from northeastern Thailand. ZooKeys 1265: 49-67, DOI: 10.3897/zookeys.1265.160661
095F7E0C6B705DEC8E9EF734D112E162.taxon	etymology	Etymology. This new species is dedicated to the late Pongrat Dumrongrojwattana, our highly respected senior who was an expert on microsnails and who provided us with many land snails references, knowledge, and inspiration.	en	Tanmuangpak, Kitti, Nahok, Benchawan, Chanlabut, Utain, Tumpeesuwan, Chanidaporn, Tumpeesuwan, Sakboworn (2025): Two new species of terrestrial microsnails of the genus Hypselostoma W. H. Benson, 1856 (Gastropoda, Eupulmonata, Hypselostomatidae) from northeastern Thailand. ZooKeys 1265: 49-67, DOI: 10.3897/zookeys.1265.160661
095F7E0C6B705DEC8E9EF734D112E162.taxon	distribution	Distribution. This species was found only on limestone wall in Pha Sam Yod, Si Bun Rueang District, Nong Bua Lamphu Province.	en	Tanmuangpak, Kitti, Nahok, Benchawan, Chanlabut, Utain, Tumpeesuwan, Chanidaporn, Tumpeesuwan, Sakboworn (2025): Two new species of terrestrial microsnails of the genus Hypselostoma W. H. Benson, 1856 (Gastropoda, Eupulmonata, Hypselostomatidae) from northeastern Thailand. ZooKeys 1265: 49-67, DOI: 10.3897/zookeys.1265.160661
2F106A505E7D525E8B8B6631EFACD4B5.taxon	description	Figs 2 C, D, 4 A – I, 5 F – L, 6 C, D; Table 2	en	Tanmuangpak, Kitti, Nahok, Benchawan, Chanlabut, Utain, Tumpeesuwan, Chanidaporn, Tumpeesuwan, Sakboworn (2025): Two new species of terrestrial microsnails of the genus Hypselostoma W. H. Benson, 1856 (Gastropoda, Eupulmonata, Hypselostomatidae) from northeastern Thailand. ZooKeys 1265: 49-67, DOI: 10.3897/zookeys.1265.160661
2F106A505E7D525E8B8B6631EFACD4B5.taxon	description	Measurements. Holotype: SH = 4.20 mm, SW = 4.02 mm, AH = 2.14 mm, AW = 2.24 mm. Paratypes: (19 specimens measured). SH = 3.82 – 4.29 mm (4.03 ± 0.11 mm), SW = 3.12 – 4.12 mm (3.88 ± 0.25 mm), AH = 1.84 – 2.27 mm (2.02 ± 0.12 mm), AW = 1.67 – 2.24 mm (2.01 ± 0.13 mm) (Fig. 7).	en	Tanmuangpak, Kitti, Nahok, Benchawan, Chanlabut, Utain, Tumpeesuwan, Chanidaporn, Tumpeesuwan, Sakboworn (2025): Two new species of terrestrial microsnails of the genus Hypselostoma W. H. Benson, 1856 (Gastropoda, Eupulmonata, Hypselostomatidae) from northeastern Thailand. ZooKeys 1265: 49-67, DOI: 10.3897/zookeys.1265.160661
2F106A505E7D525E8B8B6631EFACD4B5.taxon	diagnosis	Diagnosis. This new species differs from Hypselostoma phupaman by the presence of a non-prominent lower keel on the last whorl and the absence of basal and parietal apertural barriers. Aperture has three smooth tooth-like swellings (Fig. 4 A, G – I), whereas there are no apertural barriers in H. pongrati sp. nov. (Fig. 3 A, G – I). Spire shorter than the spire of H. pongrati sp. nov.	en	Tanmuangpak, Kitti, Nahok, Benchawan, Chanlabut, Utain, Tumpeesuwan, Chanidaporn, Tumpeesuwan, Sakboworn (2025): Two new species of terrestrial microsnails of the genus Hypselostoma W. H. Benson, 1856 (Gastropoda, Eupulmonata, Hypselostomatidae) from northeastern Thailand. ZooKeys 1265: 49-67, DOI: 10.3897/zookeys.1265.160661
2F106A505E7D525E8B8B6631EFACD4B5.taxon	description	Description. Shell (Fig. 4 A – I) concave-conical, wide-spired, with 4 ½ whorls. Large size for the genus, with shell height 3.82 – 4.29 mm, shell width 3.12 – 4.12 mm. The suture is deep. Protoconch pitted, without spiral pattern, with one whorl gradually increasing in size to the teleoconch whorls. The teleoconch has 3 ½ whorls, a very fine spiral surface, with growth lines. The body whorl widest, double keeled (prominent upper and weak lower keel). The peristome is thickened and expanded. Aperture has three smooth, tooth-like swellings, viz. an upper palatal plica, a columellar fold, and a infraparietal plica. Genital system (Fig. 6 C, D). Atrium is shorter than the vagina. Penis is longer than the epiphallus, its anterior portion is a short and gradually bulged tube, and the distal end of its posterior portion is bulged as well. Epiphallus is connected to the distal end of the penis. Epiphallus shorter than vas deferens, its anterior portion slender and cylindrical, its central portion gradually bulges, and its posterior portion is a slender tube, white and glossy. Epiphallic caecum is a short tube, attached to the anterior portion of epiphallus. The penial retractor muscle is shorter than the epiphallus, attached to the distal end of the penis. Vas deferens long, slender, entering epiphallus apically. The vagina and free oviduct are cylindrical, and the vagina is shorter than the free oviduct. The gametolytic sac is a long tube, its bulging anterior portion is surrounded by a thin sheath and connected to vagina, the distal end is a long slender and curved tube. The uterus is large, with a very thin prostate gland attached to it. The hermaphroditic duct is loosely convoluted. The albumen gland is yellowish and large. Dart apparatus absent. Radula (n = 3) (Fig. 5 F – L). Radula comprises of 154 – 165 (159 ± 5.56) rows of teeth, each row with 33 – 35 teeth. Radula formula: (9 – 10) + 7 + 1 + 7 + (9 – 10). Central tooth small, unicuspid, and triangular. Lateral teeth bicuspid and asymmetrical, consisting of a large endocone and a smaller ectocone. Seven lateral teeth on each side of the central tooth; the first tooth is largest, and the other teeth are sequentially smaller. Marginal teeth are irregular, unequally tricuspid, with an endocone larger than the ectocone and gradually change to polycuspid outwards (Fig. 5 I – L). There are nine or ten marginal teeth on each outer side of the lateral teeth (Fig. 5 F – L).	en	Tanmuangpak, Kitti, Nahok, Benchawan, Chanlabut, Utain, Tumpeesuwan, Chanidaporn, Tumpeesuwan, Sakboworn (2025): Two new species of terrestrial microsnails of the genus Hypselostoma W. H. Benson, 1856 (Gastropoda, Eupulmonata, Hypselostomatidae) from northeastern Thailand. ZooKeys 1265: 49-67, DOI: 10.3897/zookeys.1265.160661
2F106A505E7D525E8B8B6631EFACD4B5.taxon	etymology	Etymology. The specific epithet sichomphuense refers to Si Chomphu District, Khon Kaen Province, northeastern Thailand, where this species was discovered.	en	Tanmuangpak, Kitti, Nahok, Benchawan, Chanlabut, Utain, Tumpeesuwan, Chanidaporn, Tumpeesuwan, Sakboworn (2025): Two new species of terrestrial microsnails of the genus Hypselostoma W. H. Benson, 1856 (Gastropoda, Eupulmonata, Hypselostomatidae) from northeastern Thailand. ZooKeys 1265: 49-67, DOI: 10.3897/zookeys.1265.160661
2F106A505E7D525E8B8B6631EFACD4B5.taxon	distribution	Distribution. Limestone wall at Phu Kham, Si Chomphu District, Khon Kaen Province.	en	Tanmuangpak, Kitti, Nahok, Benchawan, Chanlabut, Utain, Tumpeesuwan, Chanidaporn, Tumpeesuwan, Sakboworn (2025): Two new species of terrestrial microsnails of the genus Hypselostoma W. H. Benson, 1856 (Gastropoda, Eupulmonata, Hypselostomatidae) from northeastern Thailand. ZooKeys 1265: 49-67, DOI: 10.3897/zookeys.1265.160661
86B5930D29B45365B27AC01885FAD0ED.taxon	diagnosis	Diagnosis. Shell tiny, turbinate, high-spired, or discoidal. Peristome adnate or separated from the adjacent body whorl forming a tuba; edge of peristome expanded. Aperture with four or more parietal and angular apertural lamellae or plicae (barriers), except in Hypselostoma edentatum (Panha & J. B. Burch, 2002 d) and H. pongrati sp. nov. which have no apertural barriers and H. sichomphuense sp. nov. which has only three barriers (Panha and Burch 2008; Gojšina et al. 2025). The genitalia of Hypselostoma possess a penis that is more swollen than the epiphallus; gametolytic sac connects to vagina very close to atrium, divided into two parts, with the proximal part swollen and larger than the penis (except in H. cultura (Tanmuangpak & Dumrongrojwattana, 2022), in which the gametolytic sac has a long duct between proximal and distal part, while there is no swollen proximal part in H. depressispira (Berry, 1963 )). These anatomical characters differ from the genus Aulacospira Möllendorff, 1890, whose gametolytic sac connects to the vagina far from the atrium (Dumrongrojwattana and Tanmuangpak 2020)	en	Tanmuangpak, Kitti, Nahok, Benchawan, Chanlabut, Utain, Tumpeesuwan, Chanidaporn, Tumpeesuwan, Sakboworn (2025): Two new species of terrestrial microsnails of the genus Hypselostoma W. H. Benson, 1856 (Gastropoda, Eupulmonata, Hypselostomatidae) from northeastern Thailand. ZooKeys 1265: 49-67, DOI: 10.3897/zookeys.1265.160661
