| Popis: |
Paprothites kullmanni sp. nov. urn:lsid:zoobank.org:act: E347E068-0C6F-4263-BE30-7540C182E55C Fig. 109; Table 105 Diagnosis Species of Paprothites with a conch reaching 30 mm diameter. Conch at 25 mm dm extremely discoidal, evolute (ww/dm ~0.33; uw/dm ~0.50). Whorl profile at 25 mm dm weakly depressed (ww/wh ~1.25); coiling rate low (WER ~1.60). Flanks and venter flattened, umbilical margin rounded. Sculpture on the flank with 40 sharp ribs with concave course on the flanks. Etymology Named after Jürgen Kullmann (1931–2018) in appreciation of his studies on Carboniferous ammonoids. Material examined Holotype GERMANY • Rhenish Mountains, Oese, old quarry; Hangenberg Limestone; Kullmann 1968 Coll.; illustrated in Fig. 109A; MB.C.5270. Paratypes GERMANY • 2 specimens; Rhenish Mountains, Oberrödinghausen, railway cutting; Hangenberg Limestone, bed 3d2; Weyer 1993–1994 Coll.; MB.C.31210.1–2 • 1 specimen; Rhenish Mountains, Oberrödinghausen, railway cutting; Hangenberg Limestone, bed 3e; Weyer 1993–1994 Coll.; MB.C.31211. Description Holotype MB.C.5270 (Fig. 109A) is a specimen with 26 mm conch diameter, which allows the study of the conch geometry, the ornament and parts of the suture line. The conch is extremely discoidal with a wide umbilicus (ww/dm = 0.33; uw/dm = 0.52) and a low coiling rate (WER = 1.60). The whorl profile is weakly depressed (ww/wh = 1.23) and shows flattened, weakly convergent flanks, which are separated from the also flattened venter by a tightly rounded ventrolateral shoulder. On the penultimate half whorl, the venter shows a shallow longitudinal groove that is not located on the centre of the venter, but asymmetrically on the right side. The sculpture consists of sharp ribs confined to the flanks, which are highest on the middle of the flank and emerge as small nodes in the ventrolateral area. There are 24 of these ribs on the last half whorl; the penultimate half whorl has 16 ribs. They run across the flank with a concave arc directed forward. The suture line shows a lanceolate, narrow and deep external lobe. Paratype MB.C.31211 (109B) is a fragment of a specimen of about 25 mm conch diameter. It shows a modification of the sculpture in that the ribs extend beyond the venter and form chevron-shaped sinuses. In the other aspects it largely agrees with the holotype. Remarks Paprothites kullmanni sp. nov. differs from P. dorsoplanus, P. raricostatus and P. beckeri sp. nov. by the very sharp ribs. Paprothites ruzhencevi has sharp ribs, but shows a rounded whorl profile without the distinct ventrolateral shoulder present in P. kullmanni; furthermore, P. ruzhencevi has a more depressed whorl profile (ww/wh ~1.50 or more) than P. kullmanni (w/wh ~1.25). |
