Paprothites ruzhencevi Korn & Weyer, 2003

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 : 177-178

Paprothites ruzhencevi Korn & Weyer, 2003

Figs 107–108 ; Table 104

Paprothites ruzhencevi Korn & Weyer, 2003: 100 , pl. 1 figs 21–24.

Paprothites ruzhencevi – Korn 2006: text-fig.4b–c.

Diagnosis

Species of Paprothites with a conch reaching 40 mm diameter. Conch at 15 mm dm thinly discoidal, evolute (ww/dm ~0.40; uw/dm ~0.50). Whorl profile at 15mm dm moderately depressed (ww/wh ~1.60); coiling rate low (WER ~1.55). Venter rounded, umbilical margin rounded. On the flank 25 very sharp ribs with concave course. Venter in the adult stage with incipient grooves.

Material examined

Holotype

GERMANY • Rhenish Mountains, Hasselbachtal ; Hangenberg Limestone , bed 57 ; Trostheide Coll.; illustrated by Korn & Weyer (2003: pl. 1, figs 21–24) and Korn (2006: text-fig. 4b–c), re-illustrated here in Fig. 107 ; MB.C.5240.6.

Paratypes

GERMANY • 4 specimens; Rhenish Mountains , Hasselbachtal ; Hangenberg Limestone, bed 57 ; Weyer 1993–1994 Coll.; MB.C.5240.11–14 .

Additional material

GERMANY • 40 specimens; Rhenish Mountains , Oberrödinghausen , railway cutting ; Hangenberg Limestone , bed 3d1b ; Weyer 1993–1994 Coll.; MB.C.31209.1–40 .

Description

Two well-preserved adult specimens from Oberrödinghausen are illustrated here, MB.C.31209.1 (22 mm dm; Fig. 108A ) and MB.C.31209.2 (ca. 26 mm dm; Fig. 108B ), both 22 mm in diameter. In both, at 22 mm dm, the umbilicus has exactly half of the width of the conch diameter, but the specimens differ in the shape of their whorl profile. The ww/wh ratio is 1.45 in specimen MB.C.31209.1 but 1.65 in specimen MB.C.31209.2. Both specimens show coarse ribbing. In specimen MB.C.31209.1, there are 28 ribs on the last volution, about 25 in the penultimate volution and also 25 in the volution before. The ribs are sharp and extend with a concave arch across the flank. Both specimens show two barely visible longitudinal grooves on the venter.

Remarks

Paprothites ruzhencevi differs from P. dorsoplanus and P. raricostatus in the shape and course of the ribs, which are rounded and extend almost straight across the flanks in the latter two species. Both species have a much narrower umbilicus (uw/dm = 0.35–0.40) than P. ruzhencevi (uw/dm ~0.50). Paprothites ruzhencevi differs from P. kullmanni sp. nov. in the more strongly depressed whorl profile (ww/wh ~1.50 or more in P. ruzhencevi but only ~ 1.25 in P. kullmanni ) and in the lack of a midventral groove.

Figures

Fig. 107. Paprothites ruzhencevi Korn & Weyer, 2003, holotype MB.C.5240.6 (Trostheide Coll.) from Hasselbachtal, bed 57. Scale bar units =1 mm.

Fig. 108. Paprothites ruzhencevi Korn & Weyer, 2003 from the Oberrödinghausen railway cutting, both Weyer 1993–1994 Coll. A. Specimen MB.C.31209.1 from bed 3d1b. B. Specimen MB.C.31209.2 from bed 3d1b. Scale bar units = 1 mm.