Pleuronautiloidea Hyatt, 1900

Korn, Dieter, 2025, A revised classification of the Carboniferous and Permian Nautilida, European Journal of Taxonomy 1017, pp. 1-85 : 48

Superfamily Pleuronautiloidea Hyatt, 1900

Diagnosis

Superfamily of the suborder Tainoceratina with a discoidal, subinvolute to subevolute conch. Whorl profile in early species subquadrate with distinct ventrolateral shoulder and distinct umbilical margin. Derived species show a variation of modifications including trapezoidal, inverted trapezoidal or hexagonal whorl profiles with a less angular ventrolateral shoulder and umbilical margin. Whorl overlap is always very small. Sculpture in early species with transverse ribs and ventrolateral nodes, in derived species often with ribs and several rows of nodes. Septa simply domed, in derived species with a dorsal inflexion that produces an annular process. Suture line with broadly rounded lateral lobe and shallow lobe or low saddle on the venter.

Included families

Pleuronautilidae Hyatt, 1900 (Middle Permian to Late Triassic; 1 Permian genus, 10 Permian species).

Gzheloceratidae Ruzhencev & Shimansky, 1954 (Early Carboniferous to Early Permian; 5 genera, 37 species).

Mosquoceratidae Ruzhencev & Shimansky, 1954 (Late Carboniferous to Early Permian; 3 genera, 11 species).

Aktubonautilidae Ruzhencev & Shimansky, 1954 (Early Permian; 2 genera, 2 species).

Rhiphaeoceratidae Ruzhencev & Shimansky, 1954 (Early to Late Permian; 6 genera, 15 species).

Metacoceratidae fam. nov. (Late Carboniferous to Late Permian; 12 genera, 101 species).

Foordiceratidae fam. nov. (Middle to Late Permian; 3 genera, 14 species).

Remarks

Based on the phylogenetic reconstruction that was proposed by Dzik (1984), six families within the superfamily Pleuronautiloidea are distinguished here and briefly characterised as follows:

Metacoceratidae fam. nov. – Ancestral taxa with a commonly subquadrate or weakly depressed whorl profile; sculpture with conical ventrolateral nodes and sometimes with dorsolateral nodes and ribs on the flank ( Fig. 24 ).

Gzheloceratidae Ruzhencev & Shimansky, 1954 . – Ancestral taxa with a small conch and an elliptical or reniform whorl profile; sculpture with short ribs or transversely elongated tubercles in the middle of the flank ( Fig. 25A ).

Aktubonautilidae Ruzhencev & Shimansky, 1954 . – Taxa with a semicircular or reniform whorl profile and a broadly rounded venter; sculpture with elongate nodes on the flank ( Fig. 25B ).

Mosquoceratidae Ruzhencev & Shimansky, 1954 . – Taxa with a trapezoidal whorl profile and a convex venter; sculpture with longitudinally elongated tubercles on the outer flank ( Fig. 26 ).

Rhiphaeoceratidae Ruzhencev & Shimansky, 1954 . – Taxa with an oval, reniform or trapezoidal whorl profile and a flattened venter; sculpture with short ribs on the flank ( Fig. 27 ).

Foordiceratidae fam. nov. – Derived taxa with a trapezoidal whorl profile and a flattened venter; sculpture with coarse ribs or coarse conical nodes on the outer flank ( Fig. 28 ).

Pleuronautilidae Hyatt, 1900 . – Derived taxa with parallel or convergent flanks and rounded ventrolateral shoulder; sculpture with coarse ribs and sometimes with multiple rows of nodes ( Fig. 29 ).

The absence of the midventral groove separates the Pleuronautiloidea from the Tainoceratoidea . In addition, the species of the Pleuronautiloidea usually have a rectangular, trapezoidal or inverted trapezoidal whorl profile, whereas the Tainoceratoidea have a polygonal whorl profile. The sculpture of the Pleuronautiloidea does not have the characteristic rows of nodes typical for the Tainoceratoidea .

Figures

Fig. 24. Family Metacoceratidae fam. nov. A. Pseudofoordiceras cooperi (Miller, 1945), from Miller (1945). B. Pseudofoordiceras gregarium (Miller, 1945), from Miller & Youngquist (1949). C. Pseudotemnocheilus artiense (Kruglov, 1928), from Ruzhencev & Shimansky (1954). D. Metacoceras cornutum Girty, 1911, from Girty (1915). E. Metacoceras perelegans Girty, 1911, from Girty (1915). Scale bar units = 1 mm.

Fig. 25. Families Gzheloceratidae Ruzhencev & Shimansky, 1954 and Aktubonautilidae Ruzhencev & Shimansky, 1954; both from Ruzhencev & Shimansky (1954). A. Gzheloceras ellipsoidale Ruzhencev & Shimansky, 1954. B. Aktubonautilus cruciformis Ruzhencev & Shimansky, 1954. Scale bar units = 1 mm.

Fig. 26. Family Mosquoceratidae Ruzhencev & Shimansky, 1954, both from Ruzhencev & Shimansky (1954). A. Mosquoceras simense Ruzhencev & Shimansky, 1954. B. Articheilus luxuriosum Ruzhencev & Shimansky, 1954. Scale bar units = 1 mm.

Fig. 27. Family Rhiphaeoceratidae Ruzhencev & Shimansky, 1954, all from Ruzhencev & Shimansky (1954). A. Rhiphaeoceras venustum Ruzhencev & Shimansky, 1954. B. Pararhiphaeoceras tastubense Ruzhencev & Shimansky, 1954. C. Sholakoceras bisulcatum Ruzhencev & Shimansky, 1954. Scale bar units = 1 mm.

Fig. 28. Family Foordiceratidae fam. nov. Foordiceras goliathum (Waagen, 1879), from Miller & Youngquist (1949), after Waagen (1879). Scale bar units = 10 mm.

Fig. 29. Family Pleuronautilidae Hyatt, 1900. New species to be described by Korn & Hairapetian (in press); lateral and dorsal views, reconstruction of apertural view, from Korn & Hairapetian (in press). Scale bar units = 1 mm.