Vestinautilus angulatus Korn & Bockwinkel 2022, sp. nov.
Creators: name: Korn, Dieter
name: Bockwinkel, Jürgen
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Cephalopoda
Nautilida
Trigonoceratidae
Vestinautilus
Vestinautilus angulatus

description: Vestinautilus angulatus sp. nov.
urn:lsid:zoobank.org:act: 6A498E25-5D60-4511-8BF2-5C868B8D12DF
Figs 14–15, Table 8
Diagnosis
Species of Vestinautilus with depressed, rounded-trapezoidal whorl profile (ww/wh ~1.50), venter flattened, bordered by two sharp ridges, ventrolateral shoulder angular with sharp longitudinal ridges. Whorls not embracing. Ornament with two or three weak but sharp ridges on the flank.
Etymology
From the Latin ‘ angulatum ’, referring to the two angular ventrolateral ridges.
Type material
Holotype ALGERIA • Mouydir, south of Oued Temertasset (locality MOU-E07); Argiles de Teguentour (Upper Pericyclus-Progoniatites Assemblage; early late Tournaisian); Korn et al. 2002 Coll.; illustrated in Fig. 14B; MB.C.30461.1.
Paratypes ALGERIA • 1 specimen; Mouydir, south of Oued Temertasset (locality MOU-D1); Argiles de Teguentour (Upper Pericyclus-Progoniatites Assemblage; early late Tournaisian); Korn et al. 2002 Coll.; illustrated in Fig. 14A; MB.C.30462.1 • 1 specimen; Mouydir, south of Oued Temertasset (locality MOU-E07); Argiles de Teguentour (Upper Pericyclus-Progoniatites Assemblage; early late Tournaisian); Korn et al. 2002 Coll.; illustrated in Fig. 14C; MB.C.30461.2 • 19 specimens; Mouydir, south of Oued Temertasset (localities MOU-D1, MOU-A, MOU-B1, MOU-C4, MOU-D2, MOU-V, MOU-Z); Argiles de Teguentour (Upper Pericyclus-Progoniatites Assemblage; early late Tournaisian); Korn et al. 2002 Coll.; MB.C.30462.2 – MB.C.30462.5, MB.C.30463.1 – MB.C.30463.5, MB.C.30464.1 – MB.C.30464.2, MB.C.30465.1 – MB.C.30465.3, MB.C.30466.1 – MB.C.30466.3, MB.C.30467, MB.C.30468 • 1 specimen; Sebkha de Timimoun 11 km south-west of Timimoun (locality TIM-B0); Grès de Kahla supérieur (Upper Pericyclus-Progoniatites Assemblage; early late Tournaisian); Korn et al. 2002 Coll.; MB.C.30469.
Description
Holotype MB.C.30461.1 is a phragmocone segment of about a quarter whorl with almost 9 mm whorl height (Fig. 14B). It shows a triangular whorl profile with a shallow, almost flat venter that is bordered on both sides by two elevated, sharp longitudinal ridges. Flanks, umbilical wall and dorsum form a broadly curved, semi-circular unit. On the flanks there are two longitudinal ridges, which are considerably weaker than the ridges on the ventrolateral shoulder (Fig. 15C). The suture line shows a deep, broadly rounded outer lobe and a ventrolateral saddle which has two crests because of the two longitudinal ridges. The lateral lobe is very broad and continues into a very low internal saddle (Fig. 15D).
The two paratypes MB.C.30462.1 (9 mm wh; Fig. 14A) and MB.C.30461.2 (7 mm wh; Fig. 14C) are very similar to the holotype in conch form and suture line. The two-humped ventrolateral saddle is also pronounced in paratype MB.C.30462.1 (Fig. 15B).
Remarks
Vestinautilus angulatus sp. nov. belongs to the few species of the genus with a moderately depressed whorl profile (ww/wh ~1.50) and a very weak longitudinal sculpture; in these respects, the new species differs from all other species of the genus in which the whorls are not embracing.
description: Published as part of Korn, Dieter & Bockwinkel, Jürgen, 2022, Early Carboniferous nautiloids from the Central Sahara, southern Algeria, pp. 67-108 in European Journal of Taxonomy 831 on pages 86-87, DOI: 10.5852/ejt.2022.831.1871, http://zenodo.org/record/6885198