Serometacoceras tuberculare ( Abich, 1878 ), 2025

Korn, Dieter & Ghaderi, Abbas, 2025, Late Permian nautiloids from Julfa (NW Iran), European Journal of Taxonomy 1018, pp. 1-113 : 46

Serometacoceras tuberculare ( Abich, 1878) gen. et comb. nov.

Fig. 3F

Nautilus tubercularis Abich, 1878: 20 , pl. 4 fig. 1.

Pleuronautilus tubercularis – Shimansky 1965b: pl. 15 fig. 1.

Remarks

The specimen illustrated by Abich (1878: pl. 9 fig. 1) as “ Nautilus tubercularis , nov. form.” has a conch diameter of about 85 mm and is obviously a weathered specimen ( Fig. 3F ). It suggests a discoidal, subevolute conch with a subquadrate whorl profile (ww/dm=0.38; uw/dm =0.35; ww/wh =0.91). The flanks are apparently flattened and are almost parallel; they are separated from the concave venter by a rounded ventrolateral shoulder. Half a volution bears ten ribs on the flank; these extend following a straight line in prorsiradiate direction. They begin at the umbilical margin and progressively increase to slightly raised nodules on the outer flank.

Shimansky (1965b: pl. 15 fig. 1) figured a specimen with a conch diameter of almost 40 mm. This shows an almost quadrate whorl profile with parallel flanks. The sculpture consists of five coarse ribs per quarter volution. These ribs begin at the umbilical margin and extend over the flank with a low projection. In the ventrolateral area they become stronger and form nodes.

Figures

Fig. 3. Reproductions of nautiloid figures of Abich (1878). A. “Nautilus dorso plicatus” Abich, 1878. B. “Nautilus dorso plicatus”. C. “Nautilus dorso armatus” Abich, 1878. D. “Nautilus incertus” von Arthaber, 1900. E. “Nautilus Pichleri” von Arthaber, 1900. F. “Nautilus tubercularis” Abich, 1878. Scale bar units =1 mm.