Ephippioceras pygops, Korn & Klug, 2023

Korn, Dieter & Klug, Christian, 2023, Early Carboniferous coiled nautiloids from the Anti-Atlas (Morocco), European Journal of Taxonomy 885, pp. 156-194 : 182-183

publication ID	https://doi.org/ 10.5852/ejt.2023.885.2199
publication LSID	lsid:zoobank.org:pub:8432EEFF-391F-4778-81F6-14F3F6ECAA5F
DOI	https://doi.org/10.5281/zenodo.8222739
persistent identifier	https://treatment.plazi.org/id/498203A9-1F48-441C-B413-35C683103AE1
taxon LSID	lsid:zoobank.org:act:498203A9-1F48-441C-B413-35C683103AE1
treatment provided by	Felipe
scientific name	Ephippioceras pygops
status	sp. nov.

Treatment

Ephippioceras pygops sp. nov.

urn:lsid:zoobank.org:act:498203A9-1F48-441C-B413-35C683103AE1

Fig. 18 View Fig ; Table 8 View Table 8

Diagnosis

Species of Ephippioceras with thickly pachyconic, subinvolute conch, whorl profile moderately depressed (ww/wh ~1.60) with broadly rounded venter and rounded umbilical margin. Impressed zone deep (IZR ~ 0.37). Suture line with high, subangular ventral saddle.

Etymology

Named after the brachiopod genus Pygope , because of the shape of the septal surface.

Material examined

Holotype MOROCCO • Anti-Atlas, east of Gara el Itima , 36 km east-northeast of Taouz ; uppermost Zrigat Formation; Ebbighausen & Korn 2004 Coll.; illustrated in Fig. 18 View Fig ; MB.C.31292 .

Description

Specimen MB.C.31292 ( Fig. 18A View Fig ) is a fragment of a specimen with a phragmocone diameter of about 80 mm. The whorl profile is crescent-shaped with a broadly rounded venter that continues onto the flanks, a rounded umbilical margin and a convex umbilical wall. The whorl section is moderately depressed (ww/wh=1.60) and the whorl embraces the preceding one to a rather high degree (IZR =0.37). The septal surface shows the striking bilobate shape with a median ridge that separates the septum in two concave bulges. The suture line forms a narrow, subangular saddle on the venter, a wide, broadly rounded lobe on the flank and another smaller lobe on the umbilical wall ( Fig. 18C View Fig ).

Remarks

Ephippioceras pygops sp. nov. has a far less depressed whorl profile when compared with the other species of the genus. While the ww/wh ratio is only 1.60 in E. pygops , it is close to a value of 2.00 or even higher in E. clitellarium and E. sphaericum ( Shimansky 1967) . In E. bilobatum , E. ferratum and E. verneuili , the whorl overlap is much lower (IZR ~ 0.20) than in E. pygops (IZR ~0.37). Ephippioceras spirale is difficult to compare because of the small size (19 mm dm) of the only one specimen.