Vestinautilus angulatus, Korn & Bockwinkel, 2022

Korn, Dieter & Bockwinkel, Jürgen, 2022, Early Carboniferous nautiloids from the Central Sahara, southern Algeria, European Journal of Taxonomy 831, pp. 67-108 : 86-87

publication ID	https://doi.org/ 10.5852/ejt.2022.831.1871
publication LSID	lsid:zoobank.org:pub:EAA2EAE2-DA8B-4516-B332-CB8423B8EEAA
DOI	https://doi.org/10.5281/zenodo.6903114
persistent identifier	https://treatment.plazi.org/id/6A498E25-5D60-4511-8BF2-5C868B8D12DF
taxon LSID	lsid:zoobank.org:act:6A498E25-5D60-4511-8BF2-5C868B8D12DF
treatment provided by	Felipe
scientific name	Vestinautilus angulatus
status	sp. nov.

Treatment

Vestinautilus angulatus sp. nov.

urn:lsid:zoobank.org:act:6A498E25-5D60-4511-8BF2-5C868B8D12DF

Figs 14–15 View Fig View Fig , 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 View Fig ; 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 View Fig ; 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 View Fig ; 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 View Fig ). 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 View Fig ). 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 View Fig ).

The two paratypes MB.C.30462.1 (9 mm wh; Fig. 14A View Fig ) and MB.C.30461.2 (7 mm wh; Fig. 14C View Fig ) 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 View Fig ).

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.