Abeskunus brusinianus (Clessin & W. Dybowski in W. Dybowski, 1887)

Neubauer, Thomas A., Velde, Sabrina van de, Yanina, Tamara & Wesselingh, Frank P., 2018, A late Pleistocene gastropod fauna from the northern Caspian Sea with implications for Pontocaspian gastropod taxonomy, ZooKeys 770, pp. 43-103 : 43

publication ID

https://dx.doi.org/10.3897/zookeys.770.25365

publication LSID

lsid:zoobank.org:pub:4D984FDD-9366-4D8B-8A8E-9D4B3F9B8EFB

persistent identifier

https://treatment.plazi.org/id/005B5BE1-EEEE-434C-4661-642B7389B175

treatment provided by

ZooKeys by Pensoft

scientific name

Abeskunus brusinianus (Clessin & W. Dybowski in W. Dybowski, 1887)
status

 

Abeskunus brusinianus (Clessin & W. Dybowski in W. Dybowski, 1887) Fig. 16A-I View Figure 16

Abeskunus brusinianus *1887 Zagrabica Brusiniana nob.; W. Dybowski: 52-53.

Abeskunus brusinianus 1888 Zagrabica Brusiniana n. sp. - W. Dybowski: 79, pl. 2, fig. 7.

Abeskunus brusinianus 1952 Zagrabica brusiniana W. Dyb., 1888. - Zhadin: 235, fig. 166 [partim].

Abeskunus brusinianus 1969 Pseudamnicola [( Abeskunus )] Abeskunus brusiniana (Cless. et W. Dyb.). - Logvinenko & Starobogatov: 381, fig. 367 (15).

Abeskunus brusinianus 2006 Pseudamnicola brusiniana (Clessin et W. Dybowski in W. Dybowski, 1888). - Kantor & Sysoev: 114, pl. 51, fig. J.

Abeskunus brusinianus 2016 Pseudamnicola brusiniana (Clessin et W. Dybowski in W. Dybowski, 1888). - Vinarski & Kantor: 222.

Material.

489 specimens ( RGM 1309834 , RGM 1309842 , RGM 1310194 , LV 201505 ) .

Type material.

Not traced.

Type locality.

“Kaspi-See” (Caspian Sea, no further details mentioned).

Dimensions.

4.12 × 3.82 mm ( RGM 1309834, Fig. 16A, F View Figure 16 ); 4.15 × 3.65 mm ( LV 201505, Fig. 16B, C, I View Figure 16 ); 3.00 × 2.74 mm ( RGM 1309842, Fig. 16D, E, G, H View Figure 16 ); 4.14 × 3.42 mm; 4.15 × 3.53 mm; 4.34 × 3.79 mm; 4.39 × 3.87 mm; 4.59 × 3.68 mm.

Description.

Shell broadly conical, comprising up to 4.5 whorls. Protoconch broadly domical, with almost immersed initial part; consists of 1.25 whorls, measures 525 µm in diameter; nucleus is ca. 160 µm wide; nucleus surface covered with irregular elongated wrinkles; protoconch surface wrinkled, bearing thin, irregular spiral grooves on first third, passing over irregular pattern of faint spiral grooves and wrinkles into numerous, regularly parallel spiral furrows on last third; P/T transition without growth rim, marked by onset of growth lines. Teleoconch whorls highly convex, with maximum convexity in adapical half, producing slightly stepped spire. Last whorl attains 77-85% of shell height. Aperture drop-shaped, slightly inclined, with marked adapical notch at contact to penultimate whorl. Outer peristome margin not or slightly thickened, columellar and parietal margins weakly thickened; peristome slightly expanded towards columella (protruding towards umbilicus in lateral view) and strongly towards base; weakly sinuate in lateral view, with broad but weak adapical protrusion and straight-sided abapical part. Umbilicus narrow, slit-like. Prosocline growth lines cover shell surface.

Discussion.

The species differs from the type species A. exiguus (Eichwald, 1838) in the conical shell, the taller spire, the less inflated last whorl, and the distinct umbilicus. Abeskunus brusinianus michelae Tadjalli-Pour, 1977 is much more globular than A. brusinianus . The latter species strongly reminds of and might be conspecific with A. exiguus . Pseudamnicola depressispira Logvinenko & Starobogatov, 1969, which these authors also included in the subgenus Abeskunus , differs from the presumed congeners in the valvatoid shape with very wide umbilicus and small but distinct riblets.

Pseudamnicola? brusiniana Pavlović, 1903 is a junior secondary homonym of this species, for which Neubauer et al. (2015b) introduced Pseudamnicola? babindolensis as replacement name. Because of the revised classification, P.? brusinianus [sic] Pavlović is reinstated as valid, with P.? babindolensis as its junior objective synonym ( ICZN 1999, Art. 59.4).

Distribution.

Endemic to the Caspian Sea, in the southern and middle part at a depth of> 250 m ( Logvinenko and Starobogatov 1969, Parr et al. 2007).

RGM

RGM

RGM

National Museum of Natural History, Naturalis

LV

Catholic University of Leuven

Kingdom

Animalia

Phylum

Mollusca

Class

Gastropoda

Order

Littorinimorpha

Family

Hydrobiidae

Genus

Abeskunus

Loc

Abeskunus brusinianus (Clessin & W. Dybowski in W. Dybowski, 1887)

Neubauer, Thomas A., Velde, Sabrina van de, Yanina, Tamara & Wesselingh, Frank P. 2018
2018
Loc

Abeskunus

Kolesnikov in Logvinenko & Starobogatov 1969
1969
Loc

Zagrabica Brusiniana

Clessin & W.Dybowski 1887
1887
Loc

Zagrabica Brusiniana

Clessin & W.Dybowski 1887
1887
Loc

Zagrabica brusiniana

Clessin & W.Dybowski 1887
1887