Hunyadiscus Páll-Gergely, 2016

Páll-Gergely, Barna, 2018, Systematic revision of the Plectopylinae (Gastropoda, Pulmonata, Plectopylidae), European Journal of Taxonomy 455, pp. 1-114 : 68-69

Genus Hunyadiscus Páll-Gergely, 2016

Hunyadiscus Páll-Gergely in Páll-Gergely et al., 2016: 6 .

Type species

Hunyadiscus saurini Páll-Gergely, 2016 , by original designation.

Species included

Hunyadiscus andersoni ( Blanford, 1869) , H. saurini Páll-Gergely, 2016 and H. tigrina sp. nov.

Diagnosis

The discovery of Hunyadiscus tigrina sp. nov. extends our knowledge of the geographic distribution and shell morphology of the genus Hunyadiscus . Most importantly, however, it represents the first known record of the anatomy of this genus. Therefore, the diagnosis of Hunyadiscus is extended.

Shell dextral, body whorl bluntly keeled or bluntly shouldered; protoconch with strong spiral and radial lines (spiral lines stronger than or as strong as radial lines); apertural fold absent; parietal wall with only a single lamella, or with a lamella and some additional plicae/denticles anteriorly and/or posteriorly; palatal plicae slightly sinuate, usually horizontal. Penis short, inner penial wall with a thickened, flashy structure that is rounded in the proximal part of the penis, and divided in the middle towards the distal penial part; bursa copulatrix short with ovoid bursa; diverticulum absent.

Differential diagnosis

Hunyadiscus differs from all other plectopylid genera by the protoconch sculpture, which is characterized by both radial and spiral lines, the spirals being dominant or as strong as the radial lines. The most closely related genus is probably Naggsia Páll-Gergely & Muratov, 2016 , because of the similar dextral coiling direction, the presence of spiral striation on the protoconch, the apertural fold absent or very weak and the absence of an epiphallus and because of the close geographic proximity. The two genera differ from each other in the following shell and anatomical characters: the shape of the body whorl is keeled/shouldered in Hunyadiscus and rounded in Naggsia ; the protoconch bears a strong spiral striation in Hunyadiscus , and has extremely fine spiral lines in Naggsia ; the inner penial wall has parallel folds in Naggsia , but a proximally rounded and distally divided, fleshy structure in Hunyadiscus ; the diverticulum is well-developed in Naggsia , and absent in Hunyadiscus .

Distribution

Northern Laos, northern Thailand, southern Kachin State of Myanmar, and the bordering Chinese region.

Remarks

Table 1 summarizes the key characters of species of Hunyadiscus .