Deltoceras beluga Kröger & Pohle 2021, sp. nov.
Deltoceras beluga sp. nov. urn:lsid:zoobank.org:act: 197BA0EF-574D-4EEF-ADC3-DF120829D7C5 Figs 41A, 42–43, 44A Diagnosis Discoidal, slightly involute conch with moderately expanding whorls with relative whorl width (rW) of ca 0.7–08 and with slightly flattened venter. Ornamented with fine growth lin...
| Main Authors: | , |
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| Format: | Other/Unknown Material |
| Language: | unknown |
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2021
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| Online Access: | https://zenodo.org/record/5794338 https://doi.org/10.5281/zenodo.5794338 |
| Summary: | Deltoceras beluga sp. nov. urn:lsid:zoobank.org:act: 197BA0EF-574D-4EEF-ADC3-DF120829D7C5 Figs 41A, 42–43, 44A Diagnosis Discoidal, slightly involute conch with moderately expanding whorls with relative whorl width (rW) of ca 0.7–08 and with slightly flattened venter. Ornamented with fine growth lines, which form broad lateral lobe and deep hyponomic sinus. Etymology From the Beluga whale Delphinapterus leucas (Pallas, 1776) a common guest offshore of Profilstranda in the Hinlopen Strait, Svalbard. Type material Holotype Specimen FMNH-P30321. Paratypes Two additional specimens, FMNH-P30322 and FMNH-P30326, from type locality and horizon. Type locality and horizon From Profilstranda section, Ny Friesland, Svalbard, from bed PO 07, 4 m above base of Olenidsletta Member, V 1a trilobite zone, Blackhillsian, Floian. Description The holotype is a complete specimen of ca 2.5 volutions, with a conch diameter of 42 mm and an apertural conch width and height of 12 mm and 15 mm, respectively (WWI = 0.8) (Fig. 42). The relative whorl width (rW) varies between 0.7 and 0.8 in the holotype. The conch grows with a WER of 2.78–1.96 between the first and last whorl and thus decreases with increasing diameter (Fig. 43). The whorls are rounded at the flanks with greatest width at ca the first third of the conch height from dorsum, ventral side slightly flattened and dorsum with shallow zone of impression (Fig. 44A). Zone of impression ca 1 mm deep at aperture. The conch surface is ornamented with irregularly spaced fine growth lines which form a broad lobe across the flanks and a deep, rounded, V-shaped hyponomic sinus. Hyponomic sinus at aperture of holotype ca 10 mm deep. The completely preserved body chamber has a length of 250° at the dorsum and 220° at the distal end of the hyponomic sinus. The septa form a broad lateral sinus and have a ventral distance of ca 4 mm at a conch diameter of 28 mm. The umbilical window is ca 3 mm in diameter in the holotype. Comparison Besides the type species only one other species of Deltoceras ... |
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