Mangelia odovychenae, Scarponi & Bella & Dell’Angelo & Huntley & Sosso, 2016
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publication ID |
https://doi.org/ 10.4202/app.00158.2015 |
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persistent identifier |
https://treatment.plazi.org/id/A8608798-FF83-FFBC-1F63-7090FDA642A0 |
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treatment provided by |
Felipe |
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scientific name |
Mangelia odovychenae |
| status |
sp. nov. |
Mangelia odovychenae View in CoL sp. nov.
Figs. 3D View Fig , 4E View Fig , 5F− H View Fig ; SOM 1: fig. 3D, SOM 2.
Etymology: Named after Nadiia Odovychena (wife of Bruno Dell’Angelo) for the support provided during fieldwork in Ukraine.
Type material: Holotype, MGGC-24411 , adult, moderately well preserved shell, outer lip slightly broken . Paratypes, MGGC-24512 /1–9 and MGGC-24512 /11–14 from the type locality, and MGGC-24512 /10 from Horodok (SOM 2) .
Type locality: Velyka Levada , Ukraine .
Type horizon: White sandstone of the Pidhirtsi Beds early Serravallian (~14.0−12.7 Ma).
Material.— Three topotypes from Velyka Levada: IGS- NANU-B-I-16-17/2015 (2 shs) and ZISP-62076 (1 sh) .
Diagnosis.—A small Mangelia species (shell lengthm 6.2 mm, sd 0.5 mm; shell widthm 2.6 mm, sd 0.3 mm), characterised by a relatively large, cone-shaped multispiral protoconch (lengthm 0.68 mm, sd 0.02 mm; widthm 0.61 mm, sd 0.02 mm), a turreted spire, a straight columellar lip, and a teleoconch sculpture of rounded ribs (max 11 on the second whorl), along with a dense pattern of quite uniform spiral threads. The latter are densely indented and/or beaded at the intersection with growth lines.
Description.—Shell small-sized, fusiform; spire slightly turreted (0.36 shell lengthm, sd 0.02); last whorl slightly rounded, elongated (4.0 mm, sd 0.3 mm). Protoconch tall, cone-shaped of 2.7 convex whorls (sd 0.1 wh); nucleus very small, erect, smooth as remaining whorls except the latter half, where spaced, opisthocline, curved riblets are overrun, at the protoconch transition, by faint cordlets. Protoconch-teleoconch boundary abrupt, marked by a sinusigera. Teleoconchm of 4.4 whorls (sd 0.3 wh), evenly rounded in profile, with axial and subdued spiral sculpture; suture slightly undulating. Axial sculpture of opisthocline, spaced, rounded ribs (usually 9 on second whorl), extending across the sutures on spiral whorls until the base on the last whorl; growth lines evident. Spiral sculpture of dense, fairly uniform, thin threads separated by incised lines; however on early whorls and below periphery spiral elements less homogeneous. Spiral elements densely indented (or beaded) by growth lines, the thinner sometimes truncated as in M. pseudorugulosa ). Aperture moderately narrow, sub-rectangular (lengthm 2.8 mm, sd 0.2 mm); siphonal canal short but distinct. Outer lip thin-edged, rarely preserved, slightly rounded in profile, internally thickened; anal sinus C-shaped; columellar lip straight.
Remarks.—This species shows affinities to M. pseudorugulosa with regard to the teleoconch ornamentation pattern and overall outline. However, most of the measured teleoconch features show reduced overlap between the two species (see
Fig. 2 View Fig , SOM 2) and statistical tests allow us to reject the null hypothesis for all the measured features except for the number of teleoconch whorls (e.g., M. pseudorugulosa 4.5 vs.
4.4 M. odovichenae , p = 0.52; for further details see Table 1,
SOM 3). In detail, M. odovychenae can be reliably and easily separated from M. pseudorugulosa on the basis of the bigger teleoconch (e.g., lengthm 6.3 vs. 5.3 mm, p << 0.01),
the higher last whorl (lengthm 4.0 vs. 3.3 mm, p << 0.01) and aperture size (lengthm 2.8 vs. 2.3 mm, p << 0.01) at comparable number of teleoconch whorls. In addition, M. odovychenae shows a bigger and conical-shaped protoconch with a higher number of whorls (e.g., diameterm 0.61 vs. 0.51 mm,
p << 0.01; for further details see Table 1, SOM 3). Lastly,
M. odovychenae compared to M. pseudorugulosa shows weaker and more reduced protoconch spiral sculpture and smaller, more erect nucleus ( Fig. 4E View Fig vs. Fig. 4D View Fig , SOM 2).
Stratigraphic and geographic range.—Pidhirtsi Beds, early Serravallian of the Central Paratethys.
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