Epidomatoceras Turner, 1954

Korn, Dieter & Klug, Christian, 2023, Early Carboniferous coiled nautiloids from the Anti-Atlas (Morocco), European Journal of Taxonomy 885, pp. 156-194 : 173-174

Genus Epidomatoceras Turner, 1954

Type species

Nautilus planotergatus M‘Coy, 1844 ; original designation.

Diagnosis

Genus of the family Trigonoceratidae with discoidal to pachyconic, usually subevolute conch. The first whorl is 12–20 mm in diameter with an umbilical foramen about 4–8 mm wide; the conch is rapidly increasing in height with a high coiling rate (WER usually higher than 2.50). Whorls weakly embracing, their profile is rectangular with more or less angular umbilical margin and ventrolateral shoulder. Sculpture with faint longitudinal ridges around the ventrolateral shoulder. Septa without inflexions, moderately concave. Suture line with moderately deep ventral and lateral lobes. The siphuncle has a position between the centre of the aperture and the venter (after Shimansky 1967).

Included species

British Isles ( Phillips 1836; M‘Coy 1844; Foord 1900; Turner 1954, 1965): Nautilus Doohylensis Foord, 1900 , Ireland; Epidomatoceras maccoyi Turner, 1954 , Derbyshire; Nautilus planotergatus M‘Coy, 1844 , Ireland; Epidomatoceras neilsoni Turner, 1965 , Scotland; Epidomatoceras flemingi Turner, 1965 , Scotland; Nautilus subsulcatus Phillips, 1836 , Yorkshire.

Urals and Kazakhstan ( Shimansky 1967): Epidomatoceras aemulum Shimansky, 1967 , Kazakhstan; Epidomatoceras vivum Shimansky, 1967 , South Urals.

North Africa (this paper): Epidomatoceras ebbighausenorum sp. nov., Anti-Atlas.

Remarks

Epidomatoceras belongs to a group of Early Carboniferous nautiloids of which the phylogenetic and taxonomic relationships are far from being solved ( Dzik & Korn 1992). Unlike most other late Tournaisian and Viséan evolute nautiloids, it shows the formation of a distinct umbilical margin.

The genus has a wide distribution across facies boundaries; it occurs in both shallow and deep shelf strata. For this reason, it is often found together with ammonoids.