Lilloiconcha galbao Gargominy 2025, sp. nov.
Creators: name: Gargominy, Olivier
name: Fontaine, Benoît
name: Tercerie, Sandrine
name: Zuccon, Dario
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Gastropoda
Stylommatophora
Cystopeltidae
Lilloiconcha
Lilloiconcha galbao

description: Lilloiconcha galbao Gargominy sp. nov.
Figs 6, 7
Type locality.
French Guiana, Saül, Mont Galbao.
Type material.
Holotype. French Guiana • 1 dried specimen; Saül, Mont Galbao (SAUL 47); 3.60183 ° N, 53.27239 ° W; alt. 650 m; 27 Nov. 2018; OG, SS, ST, BF (PAG & MNHN) leg.; DZ brulée et cambrouse à l’est; MNHN-IM-2013-75668. Paratypes (20). French Guiana • 1 95 % ethanol specimen; same data as the holotype; GenBank: PQ 629092; Bold: DREAL 909-23; MNHN -IM-2013-75966 • 3 95 % ethanol specimens; same data as the holotype; MNHN -IM-2013-75667 • 1 dry specimen; same data as the holotype; MNHN -IM-2012-21986 • 4 dry adult specimens; same data as the holotype; MNHN -IM-2018-896 • 11 dry juvenile specimens; same data as the holotype; MNHN -IM-2018-897.
Diagnosis.
A Lilloiconcha species with more than five whorls, as high as large, with a small umbilicus and strong ribs.
Description.
Holotype: Shell minute (height 2.2 mm, diameter 2.6 mm), dextral, globose, dome-shaped to gibbous, thin; colour corneous; whorls 5.4, inflated, rounded, separated by a deep suture; spire coiling regularly increasing. Protoconch two whorls, smooth; protoconch / teleoconch transition distinct because of change in sculpture; teleoconch sculpture of regular radial ribs, 60 on the body whorl, and a reticulate pattern consisting of fine growth-striae and dense microscopical spiral threads between the ribs. Body whorl rounded. Aperture almost circular; upper insertion of the peristome not descending towards the aperture; suture impressed. Peristome simple, sharp, neither expanded nor thickened. Umbilicus U-shaped, almost cylindrical, contained 3.8 × in the shell greater diameter.
Animal greyish, sole paler; tail without distinct caudal pit, not distinctly truncated; ocular tentacles long and gracile, inflated at the tip; eyes black, small, on the upper front of the tentacles (Fig. 7).
Paratypes: Juveniles have internal lamellae which are dissolved (not present) in adult specimens (more than 4.5–5 whorls, as the holotype): a longitudinal lamella in the middle of the parietal wall formed by up to three (one or two in subadult specimens) elongate, high (~ 40 % of the aperture diameter) teeth separated by gaps of half their length, covering ~ 1 / 8 whorl in length; at the opposite palatal side of each parietal tooth, there is a transversal lamella, extending from the outermost side of the aperture towards half of the columellar wall, principally thickened in front of its corresponding parietal tooth and extending a little bit inside along the whorl. In early juveniles this palatal lamella is reduced to a simple denticle. The lamellar complex reduces the aperture diameter to half its value.
Etymology.
The species is named after the type locality, Mont Galbao; treated as a noun in apposition.
Distribution.
This species is only known from its type locality, Mont Galbao.
Habitat.
Primary forest, under leaf litter on alkaline soils.
Remarks.
This species is attributed to genus Lilloiconcha Weyrauch, 1965 based on the conchological characters given by Weyrauch (1965), who established the name for a single species which usually has basal and parietal denticles in juvenile stages, Austrodiscus superbus tucumanus Hylton Scott, 1963 (see Schileyko 2001; Hausdorf 2005; Miquel et al. 2007). The anatomy of the new species is not known: the only adult specimen is the holotype and its body is dried and contracted inside the shell, thus not available for anatomy without cracking the shell. However, it would not help much for generic attribution as the anatomy of the type species of Lilloiconcha and its related genera (for example Radioconus Baker, 1927, type species Helix bactriola Guppy, 1868) are not known, as indicated by Hausdorf (2005).
We provide the COI sequence of one paratype which relates to the congeneric Lilloiconcha superba from Brazil (p - distance 12.5 %, GenBank MN 792606; Salvador et al. 2020).
The presence of Lilloiconcha in French Guiana is not surprising regarding the distribution of the widespread Lilloiconcha gordurasensis (Thiele, 1927) (Hausdorf 2005). However, the distribution of the genus in French Guiana seems to be limited to the mountainous habitats of the Galbao range, as it has never been collected on the Mitaraka, Trinité, or Nouragues mountains despite intensive collecting. The new species represents the first record of the superfamily Punctoidea and of the family Cystopeltidae in French Guiana.
description: Published as part of Gargominy, Olivier, Fontaine, Benoît, Tercerie, Sandrine & Zuccon, Dario, 2025, New species and new records of families, genera and species of land snails (Mollusca, Gastropoda) from French Guiana, pp. 155-194 in ZooKeys 1230 on pages 155-194, DOI: 10.3897/zookeys.1230.133585