Eocanites tener ( Vöhringer, 1960 )

Korn, Dieter & Weyer, Dieter, 2023, The ammonoids from the Gattendorfia Limestone of Oberrödinghausen (Early Carboniferous; Rhenish Mountains, Germany), European Journal of Taxonomy 882, pp. 1-230 : 202-203

Eocanites tener ( Vöhringer, 1960)

Fig. 123A ; Table 117

Protocanites planus tener Vöhringer, 1960: 176 , pl. 6 fig. 4.

Protocanites (Eocanites) planus tener – Weyer 1965: 458, pl. 8 fig. 5.

Eocanites tener – Korn 1994: 83, text-fig. 73g.

Diagnosis

Species of the genus Eocanites with a conch reaching 35 mm diameter. Conch at 12 mm dm evolute (uw/ dm ~0.50) with weakly compressed whorl profile (ww/wh ~0.90) and broadly rounded venter; conch at 20 mm dm evolute (uw/dm ~0.50) with weakly compressed whorl profile (ww/wh ~0.90) and broadly rounded venter. Ornament with very fine, rursiradiate, concavo-convex growth lines with moderately deep ventral sinus. Without ribs.

Material examined

Holotype

GERMANY • Rhenish Mountains, Oberrödinghausen , railway cutting; Hangenberg Limestone , bed 3c; Vöhringer Coll .; illustrated by Vöhringer (1960: pl. 6 fig. 4) and Korn (1994: text-fig. 73g); re-illustrated here in Fig. 123A ; GPIT-PV-64006.

Paratype

GERMANY • Rhenish Mountains , Oberrödinghausen, railway cutting; Hangenberg Limestone, bed 3b; Vöhringer Coll.; GPIT-PV-63994 .

Additional material

GERMANY • 1 specimen; Rhenish Mountains, Oberrödinghausen, railway cutting; Hangenberg Limestone, bed 3c; Vöhringer Coll.; MB.C. 31240 • 7 specimens; Rhenish Mountains, Oberrödinghausen , railway cutting ; Hangenberg Limestone , bed 3a ; Weyer 1993–1994 Coll.; MB.C. 31241.1–7 • 1 specimen; Rhenish Mountains, Oberrödinghausen , railway cutting ; Hangenberg Limestone , bed 3b ; Weyer 1993–1994 Coll.; MB.C. 31242 • 2 specimens; Rhenish Mountains, Oberrödinghausen , railway cutting ; Hangenberg Limestone , bed 3c1 ; Weyer 1993–1994 Coll.; MB.C. 31243.1–2 • 5 specimens; Rhenish Mountains, Oberrödinghausen , railway cutting ; Hangenberg Limestone , bed 3d1 ; Weyer 1993– 1994 Coll.; MB.C. 312441.1–5 • 2 specimens; Rhenish Mountains, Oberrödinghausen , railway cutting ; Hangenberg Limestone , bed 3d1 b; Weyer 1993–1994 Coll .; MB.C. 31245.1–2 .

Description

Holotype GPIT-PV-64006 is a specimen with a diameter of 18 mm ( Fig. 123A ). It is extremely discoidal and evolute (ww/dm ~0.25; uw/dm ~0.50) with an oval whorl profile (ww/wh ~0.80). The shell appears to be almost smooth, but it bears very fine growth lines with concave course on the flank.

Remarks

Eocanites tener is separated from most other species of the genus by its almost smooth shell surface. Only E. planus also has an almost smooth shell, but has a narrower umbilicus (uw/dm is less than 0.45 in E. planus , but ~ 0.50 in E. tener ).

Figures

Fig. 123. Eocanites from the Oberrödinghausen railway cutting, all Vöhringer Coll. A. Eocanites tener (Vöhringer, 1960), holotype GPIT-PV-64006 from bed 3c B. Eocanites spiratissimus (Schindewolf, 1926), neotype GPIT-PV-64007 from bed 3c. C. Eocanites spiratissimus (Schindewolf, 1926), cross section of specimen GPIT-PV-64012 from bed 3c. D–F. Eocanites spiratissimus (Schindewolf, 1926), ontogenetic development of the conch width index (ww/dm), umbilical width index (uw/dm), whorl width index (ww/wh) and whorl expansion rate (WER) of selected specimens. Scale bar units =1 mm.