Costulodonta acinaces Herbert 2020, gen. et comb. nov.
Creators: name: Herbert, David G.
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Gastropoda
Stylommatophora
Charopidae
Costulodonta
Costulodonta acinaces

description: Costulodonta acinaces (Connolly, 1933) gen. et comb. nov.
Figs 10 A–D, 11, 18I–J
Afrodonta acinaces Connolly, 1933; 149, text-fig. 1(8), pl. 7, figs 12–15.
Afrodonta acinaces – Connolly 1939: 253, text-fig. 19(8). — Solem 1970: 355. — Herbert & Kilburn 2004: 250, text-fig.
Diagnosis
Shell small, spire flat or at most fractionally raised; protoconch with close-set axial riblets (diameter ±410 μm); teleoconch sculpture of compound axial riblets with 3–4 intermediary axial threads; spiral sculpture faint; parietal region with an in-running lamella well below mid-whorl (crest sometimes nodular), plus an in-running row of 2–4 small denticles at mid-whorl, sometimes joined by a low ridge (at most two denticles visible though aperture); baso-columellar region with a deeply recessed, inrunning ridge-like denticle, scarcely visible through aperture; palatal region with two in-running ridges, narrow at first but broadening internally and each grooved medially by a furrow; an additional, deeply recessed, narrow, ridge-like denticle present just below suture; umbilicus of moderate width. Shell pale corneous brown; diameter up to 1.6 mm.
Material examined
Holotype SOUTH AFRICA • KwaZulu-Natal, Van Reenen; Mar. 1918; H.C. Burnup leg.; NHMUK 1931.6.4.2.
Paratypes SOUTH AFRICA • 12 specimens; same collection data as for holotype; NHMUK 1937.12.30.2711 to 2722.
Other material
SOUTH AFRICA – KwaZulu-Natal • 5 specimens; Van Reenen; 28.40° S, 29.39° E; Mar. 1918; H.C. Burnup leg.; NMSA A9182 • 71 specimens; same collection data as for preceding; NMSA A9183 • 10 specimens; same collection data as for preceding; NMSA A9185 • 3 specimens; same collection data as for preceding; NMSA A9208 • 15 specimens; same collection data as for preceding; NMSA A9210.
Distribution and conservation
A narrow-range endemic (Fig. 11), known only from the vicinity of Van Reenen, KwaZulu-Natal, no accurate altitude or habitat data available, presumably in leaf-litter of northern afrotemperate forest at 1500–1800 m a.s.l. Forested habitats in nature reserves along the Free State / KwaZulu-Natal border (e.g. Ingula Nature Reserve) need to be surveyed in the hope of finding extant colonies of this species in formally protected areas.
Remarks
Connolly (1939) mentioned material from Mount Vengo (on the Zimbabwe / Mozambique border) collected by Bernard Cressy. No such material is in NMSA, but a single specimen is present in NHMUK (1937.12.30.2727). This is damaged and the apertural dentition is missing (J. Ablett pers. comm., Dec. 2019). As a result it is unidentifiable, but the external sculpture is somewhat coarser than in topotypic C. acinaces gen. et comb. nov. and it seems unlikely that it is conspecific therewith. Thus, the original samples collected by Henry Burnup remain the only ones known. Judging by the number of specimens in these samples, the species must be locally common.
description: Published as part of Herbert, David G., 2020, Revision of the aperturally dentate Charopidae (Gastropoda: Stylommatophora) of southern Africa - genus Afrodonta s. lat., with description of five new genera, twelve new species and one new subspecies, pp. 1-55 in European Journal of Taxonomy 629 on pages 28-30, DOI: 10.5852/ejt.2020.629, http://zenodo.org/record/3762280