Vestinautilus concinnus, Korn & Miao & Bockwinkel, 2022

Korn, Dieter, Miao, Luyi & Bockwinkel, Jürgen, 2022, The nautiloids from the Early Carboniferous Dalle à Merocanites of Timimoun, western Algeria, European Journal of Taxonomy 789, pp. 104-129 : 122-123

publication ID	https://doi.org/ 10.5852/ejt.2022.789.1635
publication LSID	lsid:zoobank.org:pub:A475F919-D925-457E-B007-3FE2B55659A3
DOI	https://doi.org/10.5281/zenodo.6302060
persistent identifier	https://treatment.plazi.org/id/B1F94168-8870-4D86-9220-ADC18E85D2AB
taxon LSID	lsid:zoobank.org:act:B1F94168-8870-4D86-9220-ADC18E85D2AB
treatment provided by	Felipe
scientific name	Vestinautilus concinnus
status	sp. nov.

Treatment

Vestinautilus concinnus sp. nov.

urn:lsid:zoobank.org:act:B1F94168-8870-4D86-9220-ADC18E85D2AB

Fig. 11 View Fig ; Table 7 View Table 7

Etymology

After the Latin ‘ concinnus ’, meaning ‘harmonic, elegant’ and referring to the ornament.

Type material

Holotype ALGERIA • Gourara , Sebkha de Timimoun 14.5 km west-southwest of Timimoun; “Dalle à Merocanites ” (Tournaisian-Viséan boundary interval); illustrated in Fig. 11 View Fig ; MB.C.30384 .

Diagnosis

Species of Vestinautilus with weakly depressed, trapezoidal whorl profile (ww/wh ~ 1.45), venter flattened, ventrolateral shoulder defined by an angular margin produced by a distinct ridge. Another four sharp ridges are located on the outer umbilical wall and two on the outer ventral area. Whorls weakly embracing. Ornament with sharp growth lines on the flank, producing elongate granulation when crossing the spiral ridges; growth lines delicate on the venter forming a deep sinus.

Description

Holotype MB.C.30384 is an incomplete specimen 32 mm in diameter ( Fig. 11 View Fig ). It is a thickly discoidal, subevolute conch (ww/dm ~ 0.50; uw/dm ~ 0.45) with a weakly depressed whorl profile (ww/wh ~ 1.45). The whorl profile is subtrapezoidal with a broadly rounded umbilical wall, flattened and weakly converging flanks, a narrowly rounded ventrolateral shoulder and an almost flat venter. The flanks and the marginal part of the venter bear seven ridges. The interspace between the 4 th and the 5 th ridges is deepened to a longitudinal groove. The shell ornament consists of sharp, biconvex growth lines, which are coarsest on the flank; they are even coarser and produce a granulation when crossing the ridges. The suture line is only visible in some parts; broadly rounded ventral and lateral lobes are visible.

Remarks

Vestinautilus concinnus sp. nov. belongs to the species of the genus with a rather slender conch and hence a rather low ratio of whorl width and whorl height; therefore, the new species is easily distinguishable

from most species of the genus including V. padus sp. nov. A fairly similar species is only V. semiglaber , but this species has seven spiral ridges on the flank ( V. concinnus sp. nov. has only four) and a weakly concave venter (convex in V. concinnus sp. nov.) ( Foord 1900).