Diplommatina fusiformis Dumrongrojwattana, Kamtuptim & Wongkamhaeng 2020

Dumrongrojwattana, Pongrat, Kamtuptim, Chanakarn & Wongkamhaeng, Koraon, 2020, A review of Diplommatina species in eastern Thailand with the descriptions of five new species, Biodiversity Data Journal 8, pp. 57689-57689 : 57689

Diplommatina fusiformis Dumrongrojwattana, Kamtuptim & Wongkamhaeng 2020 sp. n.

Materials

Type status: Holotype. Occurrence: catalogNumber: ZRCBUU-0105 ; recordedBy: Pongrat Dumrongrojwattana; individualCount: 1; lifeStage: adult; preparations: dry shell material; Taxon: scientificName: Diplommatinafusiformis; Location: country: Thailand; stateProvince: Rayong; locality: Wat Rattanatrikoon, Khaochamao District ; verbatimCoordinates: 12°56'53.1"N 101°46'37.1"E; georeferenceProtocol: GPS; Identification: identifiedBy: Pongrat Dumrongrojwattana; dateIdentified: 2015; Event: samplingProtocol: hand collecting; eventDate: 2020; habitat: limestone hills; Record Level: language: en; collectionCode: Mollusc; basisOfRecord: PreservedSpecimen Type status: Paratype. Occurrence: catalogNumber: ZRCBUU-0104 ; recordedBy: Pongrat Dumrongrojwattana; individualCount: 18; lifeStage: adult; preparations: dry shell material; Taxon: scientificName: Diplommatinafusiformis; Location: country: Thailand; stateProvince: Rayong; locality: Wat Rattanatrikoon, Khaochamao District ; verbatimCoordinates: 12°56'53.1"N 101°46'37.1"E; georeferenceProtocol: GPS; Identification: identifiedBy: Pongrat Dumrongrojwattana; dateIdentified: 2015; Event: samplingProtocol: hand collecting; eventDate: 2020; habitat: limestone hills; Record Level: language: en; collectionCode: Mollusc; basisOfRecord: PreservedSpecimen

Description

Holotype. Shell height 2.66 mm, shell width 1.22 mm. Aperture height 0.76 mm, aperture width 0.94 mm. Shell width/shell height ratio = 0.46. Aperture width/aperture height ratio = 1.23 (Fig. 3 A).

Paratypes (5 shells). Shell height 2.66-2.74 mm (2.65 ± 0.07 mm) shell width 1.21-1.29 mm (1.25 ± 0.03 mm). Aperture height 0.76-0.87 mm (0.78 ± 0.06 mm). Aperture width 0.82-0.98 mm (0.91 ± 0.06 mm). Shell width/shell height ratio = 0.47 ± 0.02. Aperture width/aperture height ratio = 1.18 ± 0.10.

Description. Shell minute dextral, fusiform, translucent, light orange, with about 6 ½ whorls that increase regularly in size and diameter until the last whorl which is slightly smaller in diameter than the penultimate whorl; protoconch orange, smooth, consisting of 1 ¼ whorls; teleoconch light orange, about 5 ¼ whorls; sculpture consists of thin, widely-spaced radial ribs with discernible spiral striae between the ribs; there are about 10 ribs/mm on the penultimate whorl and about 8 ribs/mm on the body whorl; sutures deep; umbilicus closed; aperture rounded, peristome thickened and expanded; columellar lamella relatively small (Fig. 4 ).

Diagnosis

Diagnosis. Shell minute, dextral, translucent light orange, teleoconch sculpture consisting of widely-spaced axial ribs with spiral striae between the ribs; aperture rounded, columellar lamella relatively small, peristome, thickened and expanded.

Etymology

We named this new species " fusiformis " based on its fusiform shell shape.

Distribution

Only known from the type locality.

Taxon discussion

Diplommatina fusiformis sp. n. is similar to the southern species, D. hidagai Panha, 1998, but it differs by its more widely-ribbed shell, its more slender spire and its less prominent columellar lamella.

Figures

Figure 3. 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.

Figure 4. Synopsis of eastern diplommatind species. A) Diplommatina crispata khaochamaoensis, B-C) Holotype and paratypes of D. burapha sp. n., D-E) Holotype and paratypes of D. chadathongae sp. n., F-G) Holotype and paratypes of D. chantaburiensis sp. n., H-I) Holotype and paratypes of D. fusiformis sp. n. and J-K) Holotype and paratypes of D. khwantongae sp. n. Scale bar = 1 mm.