Cochlis ukrainensis, Pedriali & Sosso & Dell’Angelo, 2019

Pedriali, Luca, Sosso, Maurizio & Dell’Angelo, Bruno, 2019, Naticid gastropods from the middle Miocene of western Ukraine, Zootaxa 4700 (2), pp. 151-195 : 166-168

Cochlis ukrainensis sp. nov.

(Fig. 24.1−6)

Type material. Holotype and 6 paratypes ( Table 5 ).

Type locality. Varovtsi , Ukraine .

Type stage. Middle Miocene (Upper Badenian) .

Etymology. The name refers to Ukraine, the country where the village of Varovtsi is located.

Other material. Varovtsi: NP 10023 (2 shells); MZB 50516 (1 shell, Fig. 24.6); BD 164 (2 shells); MS 103 (2 shells). Horodok: NP 10022 (1 shell).

Diagnosis. Shell globose with depressed, low-conical spire and globular last whorl. Umbilicus deep, mediumsized. Parietal callus subrectangular, thick; anterior lobe flat and rounded. Funicle cord-like, thick; umbilical callus small, thick, semicircular in outline and separated from parietal callus by broad, regularly arched notch. Colour pattern of whitish to brown, uneven collabral stripes over a uniform light brown to brown background.

Description. Protoconch small, depressed turbiniform, of 1.75 gently convex, apparently smooth whorls, tip medium-sized. Teleoconch globose, solid. Spire low-conical, rather depressed, whorls convex, suture slightly incised. Last whorl globular, moderately produced toward aperture, slightly expanded in a few young specimens. Subsutural shelf wide, flat or gently sloping, periphery above midline. Aperture D-shaped, in prosocline plane. Pari- etal callus moderately thick, subrectangular, with rounded, flat anterior lobe at level of umbilical border. Umbilicus deep, medium-sized. Funicle cord-like, moderately thick, separated from umbilical wall by narrow spiral furrow. Umbilical callus small, thick, semicircular in outline, located at abapical one-third of inner lip, separated from parietal callus by broad, regularly arched notch. Basal fasciole wide, depressed. Surface with rather dense, thin growth lines, stronger on subsutural shelf and basal fasciole; faint spiral striation present on body whorl. Background uniform light brown to brown, with pattern of uneven whitish collabral stripes. No opercula found.

Remarks. Cochlis ukrainensis sp. nov. is quite similar to the late Miocene to early Pleistocene South European subspecies C. raropunctata raropunctata (Fig. 24.7−9), but differs from it in having: 1) a protoconch with 0.5 more whorls, with smaller diameter of the first half-whorl (average values 0.195 mm and 0.357 mm, respectively); 2) a wider, subrectangular parietal callus, with a better developed anterior lobe; 3) a smaller umbilicus; 4) an umbilical callus demarcated from the parietal callus by a broad, arched notch (reverse J-shaped in C. raropunctata raropunctata ); 5) a depressed basal fasciole, not sharply edged abaxially by a low step; and 6) a different and less variable colour pattern of uneven whitish to brown collabral stripes (a reddish-brown pattern of dots or spots, often arranged in collabral rows, spirally elongated spots, chevron marks, and irregular spiral broken lines in C. raropunctata raropunctata ). It is also worth noting that C. ukrainensis sp. nov. attains a smaller size.

Distribution. Middle Miocene: Central Paratethys (Upper Badenian) in Ukraine (this paper).

Tables

TABLE 5. Cochlis ukrainensis sp. nov., type material, repository numbers and basic parameters. Spm stands for number of specimens; H stands for shell height (indicated as the maximum value if the paratype includes more than one shell)

type material	repository	locality	spm	material	H (mm)	figures
Holotype	MPUM 11735	Varovtsi	1	shell	35.41	24.1a–c
Paratype 1	MPUM 11736	Varovtsi	1	shell	21.27	24.2a–b
Paratype 2	MZB 32145	Varovtsi	1	shell	17.90	24.3
Paratype 3	ZISP 1/62193	Varovtsi	1	shell	26.27	24.4a–b
Paratype 4	IGS NANU B-III-3/2018	Varovtsi	1	shell	6.90	24.5
Paratype 5	MPUM 11737	Varovtsi	1	shell	21.22
Paratype 6	IGS NANU B-III-4/2018	Varovtsi	1	shell	17.56

TABLE 5. Cochlis ukrainensis sp. nov., type material, repository numbers and basic parameters. Spm stands for number of specimens; H stands for shell height (indicated as the maximum value if the paratype includes more than one shell)