Cotyorica nemethi, Grego & Szekeres, 2017

Grego, Jozef & Szekeres, Miklós, 2017, Cotyorica nemethi n. gen. n. sp., a remarkable Tertiary relict of the subfamily Phaedusinae (Gastropoda: Pulmonata: Clausiliidae) from northern Turkey, Ecologica Montenegrina 10, pp. 26-30 : 27-29

Cotyorica nemethi n. sp.

( Figs 1 , 2 )

Type material: Turkey, Ordu Province, coastal slope between Perşembe and Mersin (41°07' N 37°47' E), 20 m, leg. L. Németh 30.06.1991. Holotype, HNHM 100140 , to be deposited at the Hungarian Natural History Museum (Budapest).

Diagnosis: Non-decollated small species of the Phaedusinae with strongly costate neck, all around serrate peristome, high positioned, deep divided lamella inferior ending in two parallel branches, uninterrupted lamella subcolumellaris, as well as short upper and longer lower plicae on the lateral side.

Description: The colourless shell with slightly bent spire consists of 9 1 / 3 flat whorls. The dense ribs of the surface become stronger, sharper and widely spaced at the neck. The ovoid peristome is projected, at the basis not backward-bent. Its wide, reflexed margin has strong plicae all around, except at the sinulus. The lamella superior is moderately emerged, in front view not more conspicuous than the interlamellar plicae. Inward it is smoothly continuous with the lamella spiralis. Deeper than visible through the aperture the lamella inferior divides in two parallel branches, which descend along the lamella spiralis and terminate marginally as strong plicae above half height of the aperture. The uninterrupted lamella subcolumellaris also ends marginally, separated from the lower branch of the inferior by a strong plica. The plica principalis starts ventrolaterally and, gradually converging toward the suture, reaches close to the aperture. On the lateral side it is accompanied by a short upper and a farther forward reaching, twice longer lower palatal plica. The deep clausilium plate is not visible through the aperture.

Dimensions of the holotype: shell height 11.5 mm, shell width 2.9 mm, aperture height 2.2 mm, aperture width 1.7 mm.

Etymology: The new species is named after László Németh, the collector of the type specimen and an esteemed friend of the authors, who substantially contributed to the research of the Turkish malacofauna.

Habitat: Cotyorica nemethi n. sp. was recovered as an empty shell from a litter-soil sample collected at a cliff. As its closest relatives Graecophaedusa sperrlei Rähle, 1982 and Nothoserrulina subterranea Németh & Szekeres, 1995 were found in narrow underground passages between rocks ( Németh & Szekeres 1995; Reischütz et al. 2008), it is assumed that this species may have similar habitat preference. This is also suggested by the highly local occurrence of the new species in a zoogeographically well researched region. The holotype may have been washed out from crevices of the cliff by rain water.

Remarks

Among non-decollated western Phaedusinae C. nemethi n. sp. shows superficial similarity to Serrulina serrulata (Pfeiffer, 1847) that differs markedly by its steeply descending and low ending lamella inferior, a feature shared between members of the genera Serrulina Mousson, 1873 , Dobatia Nordsieck, 1973 , Sciocochlea Boettger, 1935 , and Tsoukatosia Gittenberger, 2000 . By contrast, the high positioned lamellae inferior and subcolumellaris of the new species ( Fig. 2 ) resemble those seen in the monotypic genera Graecophaedusa Rähle, 1982 and Nothoserrulina Németh & Szekeres, 1995 . Nevertheless, C. nemethi n. sp. is well distinguishable from Graecophaedusa sperrlei by the narrow apex and less retracted palatal plicae, from Nothoserrulina subterranea by the spindle-shaped shell and the absence of minor folds between the upper and lower plicae, and from both species by the projected aperture with non-recessed basal rim, and the strongly serrate parietal peristome margin. Considering these differences relative to the morphological coherence of species in the non-monotypic genera (e.g., Serrulina , Sciocochlea, Tsoukatosa ), they justify the classification of the new species in a distinct genus.

Ample all year round rainfall and the narrow, within 15°C range of monthly average temperatures of the southern and eastern Black Sea coast provide ideal climatic conditions for the survival of Phaedusinae species, which were abundant elements of the European Clausiliidae fauna before the Pleistocene period ( Nordsieck 2000; Reischütz et al. 2016). This temperate region is home to four highly endemic species ( Fig. 3 ), all of which live in shallow subterranean habitats ( Culver & Pipan 2014) and, in accordance with their relict status, belong to monotypic genera.

Figures

Figure 1. Cotyorica nemethi n. sp. Holotype, 11.5 mm.

Figure 2. Lamella positions in the aperture of Cotyorica nemethi n. sp. The lamellae superior (Lsu), inferior (Lin) and subcolumellaris (Lsc) are marked.

Figure 3. Occurrence of highly endemic Phaedusinae species along the northeastern Aegean and the Black Sea coast. Graecophaedusa sperrlei Rähle, 1982 (1); Nothoserrulina subterranea Németh & Szekeres, 1995 (2); Cotyorica nemethi n. sp. (3); Pontophaedusella ofensis Nordsieck, 1994 (4); Truncatophaedusa evae Majoros, Németh & Szili- Kovács, 1994 (5).