Georissa digitinota Klongkaew, Poeaim & Dumrongrojwattana 2024, sp. nov.
Georissa digitinota Klongkaew, Poeaim & Dumrongrojwattana sp. nov. Figs 2 D, 4 M – P, 5 M – P Type examined. Holotype • ZRCBUU 0906 (Fig. 2 D); SH = 2.27 mm, SW = 1.68 mm, AH = 0.85 mm, AW = 1.03 mm, W = 4.25–4.5. Paratypes • ZRCBUU 0907 (Fig. 4 M – P) (9 shells); Shell measurements: SH = 2.34–2.72 mm (2.46 ± 0.12 mm), SW = 1.66–1.86 mm (1.76 ± 0.06 mm), AH = 0.87–1.00 mm (0.93 ± 0.04 mm), AW = 0.96–1.06 mm (1.00 ± 0.04 mm), W = 4–4.5 (all type material from type locality; 24 June 2021, P. Dumrongrojwattana leg). Type locality. Thailand, Khao Noi Bodhiyan Temple, Mueang Satun district, Satun Province; 06 ° 45 ' 24.2 " N, 100 ° 01 ' 54.2 " E. Etymology. The specific designation “ digitinota ” is for the fingerprints-like sculpture on the protoconch. Diagnosis. Shell minute, globosely conical, orangish to brownish, protoconch round to slightly ellipsoid and ellipsoidal to irregular sculpture with oval fingerprint-like indentation. Body whorl peripherally rounded with more than 30 spiral lines. Aperture semi-rounded. Umbilicus closed. Operculum corneous with apophysis, paucispiral, opaque white, and semi-rounded. Description. Shell minute, dextral, orangish to brownish, globosely conical with 4.25–4.5 whorls. Protoconch brownish consists of 1 whorl, round to slightly ellipsoid, covered with ellipsoidal to irregular sculpture and a large oval fingerprint-like indentation present (Fig. 4 N, O). Teleconch, orangish to brownish, consists of 3.25–3.5 whorls. Body whorl peripherally rounded, sculptured with more than 30 spiral lines on the body whorl, crossed with very weak oblique growth lines at the basal part of the body whorl (Fig. 4 M). Suture incised. Aperture semi-rounded. Peristome thin, sharp, unexpanded or thickened and not reflected. Umbilicus closed. Operculum paucispiral, nucleus submarginal, corneous, opaque white, semi-rounded, thin, smooth outside surface with apophysis, inside surface with an arched peg arising from base (Fig. 4 P). Radula. Ribbon-like, slender, longer and delicate towards the outside, rhipidoglossate (Fig. 5 M – P). Central tooth five small teeth, trapezoid shape. Lateral teeth five teeth present, claw-like with 7–13 alternately long and short denticles decreasing in size from the first lateral tooth toward the 5 th lateral tooth. Marginal teeth two teeth, claw-like with 12–14 equal-sized denticles. Radula formula 2: 5: 1 + 1 + 1 + 1 + 1 + 1: 5: 2. Differential diagnosis. Georissa digitinota sp. nov. resembles G. monterosatiana Godwin-Austen & Neville, 1879. Georissa monterosatiana differs in having a less convex body whorl, smooth protoconch, and more lirae (9–11 instead of more than 30 spiral lines).
Institutions
- Burapha University (TH)
- King Mongkut's Institute of Technology Ladkrabang (TH)
Publication Details
- Journal
- Zenodo (CERN European Organization for Nuclear Research)
- Published
- 2024-10-04
- DOI
- https://doi.org/10.5281/zenodo.13891565
- Primary Topic
- Diatoms and Algae Research
- Type
- article
- Field-Weighted Citation Impact
- 0.00