taxonID	type	description	language	source
C91866474203895BFD8658D2FB2FC4F3.taxon	diagnosis	Diagnosis Gephuroceratoidea with sutural formula (E 2 E 1 E 2) L: I or (E 2 E 1 E 2) L: U I; lateral lobe simple, usually rounded.	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C91866474203895BFE6A5FA8FCC2C646.taxon	diagnosis	Diagnosis Ponticeratidae with moderately wide to wide umbilicus; growth lines with high ventrolateral projection.	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C91866474203895AFDD35D7DFCDDC2FA.taxon	type_taxon	Type species Pseudoprobeloceras nebechense Bensaïd, 1974 (original designation).	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C91866474203895AFDD35D7DFCDDC2FA.taxon	diagnosis	Diagnosis Genus of the subfamily Ponticeratinae with extremely discoidal, subevolute conch. Without ventrolateral grooves. Suture line with relatively narrow external lobe, very low median saddle, very small E 2 lobe, shallow and rounded lateral lobe. Suture line formula (E 2 E 1 E 2) L: I.	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C91866474203895AFDD35D7DFCDDC2FA.taxon	discussion	Remarks Pseudoprobeloceras can be considered the stratigraphically earliest and morphologically simplest genus of the gephuroceratids. The most important morphological feature is the very low median saddle, which is indicative of a newly acquired trait. In the early forms of Ponticeras, which have the same suture line formula as Pseudoprobeloceras, the median saddle is already much more prominent and the external lobe is much wider than in Pseudoprobeloceras.	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C918664742028956FDB859BCFEFCC373.taxon	description	Figs 4 A, C, 5 – 6	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C918664742028956FDB859BCFEFCC373.taxon	diagnosis	Diagnosis Species of Pseudoprobeloceras reaching about 70 mm conch diameter with thinly discoidal, subevolute conch between 30 and 50 mm dm (ww / dm decreasing from ~ 0.30 to ~ 0.25; uw / dm increasing from ~ 0.30 to ~ 0.38); coiling rate moderate (WER ~ 1.95). Whorl profile weakly compressed (ww / wh = 0.65 – 0.80); umbilical wall oblique, umbilical margin broadly rounded, venter rounded. Growth lines very fine. Suture line with V-shaped external lobe with strongly diverging flanks, median saddle low, E 2 lobe small, rounded or pointed, ventrolateral saddle almost symmetrically rounded, lateral lobe broadly rounded.	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C918664742028956FDB859BCFEFCC373.taxon	materials_examined	Material examined Lectotype GERMANY • Rhenish Mountains, Oberscheld (Grube Prinzkessel); late Givetian (Red Ironstone); Welsch 1912 Coll.; SMF. Mbg. 2322. Illustrated by Wedekind (1918: pl. 21 figs 1 – 2) and House & Ziegler (1977: pl. 1 figs 21 – 22); re-illustrated here in Fig. 4 A. Additional material GERMANY • 1 specimen; Rhenish Mountains, Oberscheld; late Givetian (Red Ironstone); Erbreich Coll.; MB. C. 7696 • 1 specimen; Rhenish Mountains, Oberscheld (Grube Gründchesseite); late Givetian (Red Ironstone); Lotz 1901 – 1902 Coll.; MB. C. 30415 • 1 specimen; Rhenish Mountains, Oberscheld (Grube Prinzkessel); late Givetian (Red Ironstone); Fremdling 1922 Coll.; MB. C. 4287 • 1 specimen; Rhenish Mountains, Oberscheld (Grube Volpertseiche); late Givetian (Red Ironstone); Bender 1901 Coll.; MB. C. 30416 • 3 specimens; Rhenish Mountains, Oberscheld (“ Tiefe Grube ”); late Givetian (Red Ironstone); Etzold 1910 Coll.; MB. C. 22164, MB. C. 30417.1, MB. C. 30417.2 • 1 specimen; Rhenish Mountains, Oberscheld; late Givetian (Red Ironstone); MB. C. 30418 • 1 specimen; Rhenish Mountains, Oberscheld (Grube Prinzkessel); late Givetian (Red Ironstone); Welsch 1913 Coll.; SMF. MB. C. 2326.	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C918664742028956FDB859BCFEFCC373.taxon	description	Description Seven specimens are selected for description and illustration:	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C918664742028956FDB859BCFEFCC373.taxon	materials_examined	Lectotype SMF. Mbg. 2322: rather well-preserved specimen with 38 mm diameter, shell surface and suture line preserved (Fig. 4 A). Specimen Mbg. 2326, the holotype of “ Gephyroceras Barroisi ”: is a specimen with 51 mm diameter (Fig. 4 C).	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C918664742028956FDB859BCFEFCC373.taxon	description	MB. C. 22164: fragmentary, somewhat corroded specimen with 53 mm conch diameter in haematitic, micritic limestone; one third of the last volution belongs to the body chamber (Fig. 5 B). MB. C. 4287: rather complete, somewhat corroded specimen with 46 mm conch diameter in haematitic, sparitic limestone; one quarter of the last volution belongs to the body chamber (Fig. 5 C). MB. C. 7696: rather complete, somewhat corroded specimen with 45 mm conch diameter in haematitic limestone; one half of the last volution belongs to the body chamber (Fig. 5 D). MB. C. 30417.1: exfoliated specimen with 37 mm conch diameter in haematitic limestone; only a small part belongs to the body chamber (Fig. 5 E). MB. C. 30418: deformed but otherwise rather well-preserved specimen with 59 mm conch diameter in haematitic sparitic limestone; conch widely covered with shell. Part of the external suture line visible (Fig. 5 A). Lectotype SMF. Mbg. 2322 is a specimen with 38 mm diameter (Fig. 4 A). It is thinly discoidal; the venter is weakly flattened. It is separated, on the last quarter whorl, from the converging flanks by a pronounced ventrolateral shoulder. The specimen has rather coarse growth lines, particularly in inner whorls; they become lamellar on last volution with a high ventrolateral projection. Specimen SMF. Mbg. 2326, the holotype of Pseudoprobeloceras barroisi, is a specimen 51 mm in diameter (Fig. 4 C). Its umbilical wall is oblique, the flanks converge and the ventrolateral shoulder is prominent. On the last half volution, the specimen shows the transformation from the preadult stage into the adult stage by a rather rapid opening of the umbilicus. The shell ornamentation is poorly preserved. The additional material allows the study of the proportions, ornamentation and suture lines of the shell in a growth interval between 27 and 59 mm diameter (Fig. 5). In the interval between 30 and 50 mm diameter, the conch becomes slenderer (ww / dm decreasing from ~ 0.35 to ~ 0.25) and more widely umbilicate (uw / dm increasing from ~ 0.30 to ~ 0.28). The coiling rate is moderately high (WER ~ 1.95) at 50 mm dm. The compressed whorl profile (ww / wh decreasing from ~ 0.80 to ~ 0.65) has an oblique umbilical wall, rounded umbilical margin, weakly converging flanks and rounded venter. Shell remains are poorly preserved in the material; the ornament is obviously very weak. Specimen MB. C. 30418 shows the transformation from the pre-adult to adult morphology (Fig. 5 A). Up to a conch diameter of 45 mm the proportions are similar to the other specimens, but thereafter there is a rapid change in the rate of overlap of the earlier whorls and a reduction in the rate of coiling. Although the specimen is somewhat distorted by tectonics, it shows the differences from the pre-adult stage. At 59 mm conch diameter, the whorl profile is compressed with a rounded umbilical margin, weakly convergent flanks, subangular ventrolateral shoulders and a weakly flattened venter. Parts of the suture line are visible in several specimens. In specimen MB. C. 30417.1 it shows the outline characteristic of the genus with a V-shaped external lobe with strongly diverging flanks, a very low lateral saddle, a deep E 1 lobe and narrowly rounded E 2 lobe. The ventrolateral saddle is almost symmetrical and broadly rounded, the lateral lobe is broadly rounded (Fig. 6 A).	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C918664742028956FDB859BCFEFCC373.taxon	discussion	Remarks Pseudoprobeloceras barroisi is here synonymised with P. pernai, although its holotype is not well preserved and thus does not allow an accurate description. Up to about 40 mm conch diameter, it closely resembles the typical morphology of P. pernai; on the last half volution it shows the transformation to the adult morphology with its opened umbilicus. Pseudoprobeloceras pernai differs from P. applanatum (Wedekind, 1918) in the shape of the venter; this is rounded in P. pernai, whereas in P. applanatum it is slightly flattened and bordered by a narrow, rounded ventrolateral shoulder on the flanks. The specimens from Hassi Nebech attributed to P. pernai by Petter (1959), House et al. (1985) and Bockwinkel et al. (2013 a) differ by their much higher coiling rate (WER = 2.30 – 2.45 between 27 and 32 mm dm) from the material from the type region (WER ~ 1.90 at 45 mm dm). They have to be attributed to the species Pseudoprobeloceras nebechense Bensaïd, 1974, as originally stated by Bensaïd (1974).	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C9186647420E8955FD9B5832FD60C536.taxon	description	Figs 4 B, 7	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C9186647420E8955FD9B5832FD60C536.taxon	diagnosis	Diagnosis Species of Pseudoprobeloceras reaching about 50 mm conch diameter with thinly discoidal, subinvolute conch at 30 mm dm (ww / dm ~ 0.35; uw / dm ~ 0.28); coiling rate moderate (WER ~ 1.95). Whorl profile weakly compressed (ww / wh ~ 0.85); umbilical wall oblique, umbilical margin broadly rounded, venter weakly flattened, ventrolateral shoulder narrowly rounded. Growth lines very fine, strongly biconvex with linguiform ventrolateral projection. Suture line with V-shaped external lobe with diverging flanks; median saddle low, E 2 lobe small, rounded, ventrolateral saddle almost symmetrically rounded, lateral lobe asymmetrically rounded.	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C9186647420E8955FD9B5832FD60C536.taxon	materials_examined	Material examined Holotype GERMANY • Rhenish Mountains, Oberscheld (Grube Prinzkessel); late Givetian (Red Ironstone); Welsch 1912 Coll.; SMF. Mbg. 2323. Illustrated by Wedekind (1918: pl. 21 fig. 3) and House & Ziegler (1977: pl. 1 figs 26 – 27); re-illustrated here in Fig. 4 B. Additional material GERMANY • 1 specimen; Rhenish Mountains, Oberscheld (Grube Volpertseiche); late Givetian (Red Ironstone); Koch Coll.; MB. C. 22157.	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C9186647420E8955FD9B5832FD60C536.taxon	description	Description Two specimens are selected for description and illustration: Holotype SMF. Mbg. 2323: rather well-preserved specimen with 24 mm diameter in haematitic limestone (Fig. 4 B). MB. C. 22157: incomplete specimen with about 44 mm diameter in haematitic limestone; more than half of the last volution belong to the body chamber (Fig. 7 A). Holotype SMF. Mbg. 2323 with 24 mm diameter is discoidal and subinvolute (Fig. 4 B). Its umbilical wall is rounded; the flanks slightly flattened and converge to the rather broad venter. A pronounced, weakly angular ventrolateral shoulder is present on the entire last volution. The growth lines are lamellar; there are faint riblets around the umbilicus. The suture line has a large, subdivided external lobe with very small E 1 prongs, a low median saddle and a very deep E m lobe. Specimen MB. C. 22157, 35 mm in diameter, has a thinly discoidal and subinvolute conch with a compressed whorl profile (Fig. 7 A). It is widest near the mid-flank and has an oblique umbilical wall and broadly rounded umbilical margin; the flanks are convex and weakly convergent, the outer flanks are weakly concave and separated from the weakly flattened venter by a narrowly rounded ventrolateral shoulder. The shell remains show rhythmically strengthened growth lines with broadly rounded dorsolateral projection, a wide lateral sinus and a narrow and high, lingulate ventrolateral projection. The suture line is barely visible in the ventral portion because of poor preservation; it possesses a V-shaped external lobe, a narrowly rounded ventrolateral saddle and a broadly rounded lateral lobe (Fig. 7 B).	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C9186647420E8955FD9B5832FD60C536.taxon	discussion	Remarks Pseudoprobeloceras applanatum differs in the slightly stouter conch shape (ww / dm ~ 0.35) from P. pernai (ww / dm = 0.20 – 0.30) and the narrower umbilicus (uw / dm ~ 0.28 in contrast to ~ 0.33). The main distinguishing character to separate P. applanatum from P. pernai is the shape of the venter; while this is rounded in P. pernai, in P. applanatum it is slightly flattened and bordered by a narrowly rounded ventrolateral shoulder from the flanks.	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C9186647420C8954FD155A60FE2AC5EE.taxon	type_taxon	Type species Ammonites aequabilis Beyrich, 1837 (original designation).	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C9186647420C8954FD155A60FE2AC5EE.taxon	diagnosis	Diagnosis Genus of the subfamily Ponticeratinae with extremely discoidal, subevolute to evolute conch. Often with ventrolateral grooves. Suture line with very wide external lobe, moderately high median saddle, small E 2 lobe, shallow and rounded lateral lobe. Suture line formula (E 2 E 1 E 2) L: I or (E 2 E 1 E 2) L: U I.	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C9186647420C8954FD155A60FE2AC5EE.taxon	discussion	Remarks Ponticeras is, next to Pseudoprobeloceras, the stratigraphically oldest genus of the Gephuroceratoidea. The two genera mainly differ in the shape of the external lobe; in Pseudoprobeloceras it is quite narrow with a low median saddle and in Ponticeras it is very broad with a quite high median saddle. The genera of the closely related family Gephuroceratidae differ from Ponticeras in the acute lateral lobe, which is rounded in Ponticeras.	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C9186647420C8950FDF65EAEFC70C283.taxon	description	Figs 4 D, 8 – 10	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C9186647420C8950FDF65EAEFC70C283.taxon	diagnosis	Diagnosis Species of Ponticeras reaching about 120 mm conch diameter with extremely discoidal, subevolute conch between 40 and 60 mm dm (ww / dm = 0.20 – 0.25; uw / dm = 0.40 – 0.45); coiling rate low (WER = 1.70 – 1.75). Whorl profile weakly compressed (ww / wh = 0.65 – 0.75); umbilical wall oblique and flattened, venter narrowly rounded. Growth lines very fine, strongly biconvex. Flanks often with a spiral ridge on the outer side of the umbilicus parallel to the umbilical seam. Suture line with V-shaped external lobe; median saddle moderately high, E 2 lobe small, pointed, ventrolateral saddle and lateral lobe asymmetrically rounded.	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C9186647420C8950FDF65EAEFC70C283.taxon	materials_examined	Material examined Lectotype GERMANY • Rhenish Mountains, Oberscheld (Sessacker); late Givetian (Red Ironstone); Beyrich 1835 Coll.; MB. C. 4289.1. Illustrated here in Fig. 8 D. Paralectotypes GERMANY • 1 specimen; Rhenish Mountains, Oberscheld (Sessacker); late Givetian (Red Ironstone); Beyrich 1835 Coll.; MB. C. 30425 • 1 specimen; Rhenish Mountains, Oberscheld; late Givetian (Red Ironstone); Beyrich 1835 Coll.; MB. C. 5600. Additional material GERMANY • 1 specimen; Rhenish Mountains, Dillenburg; late Givetian (Red Ironstone); Erbreich Coll.; MB. C. 4293 • 1 specimen; Rhenish Mountains, Dillenburg; late Givetian (Red Ironstone); MB. C. 30419 • 1 specimen; Rhenish Mountains, Nanzenbach (Grube Königszug); late Givetian (Red Ironstone); Dannenberg Coll.; MB. C. 30420 • 2 specimens; Rhenish Mountains, Oberscheld; late Givetian (Red Ironstone); Erbreich Coll.; MB. C. 4289.2, MB. C. 5576 • 3 specimens; Rhenish Mountains, Oberscheld; late Givetian (Red Ironstone); Kauth Coll.; MB. C. 4290, MB. C. 30421.1, MB. C. 30421.2 • 1 specimen; Rhenish Mountains, Oberscheld; late Givetian (Red Ironstone); Liebe Coll.; MB. C. 30422 • 1 specimen; Rhenish Mountains, Oberscheld (Grube Königszug); late Givetian (Red Ironstone); Jung 1902 Coll.; MB. C. 30423 • 1 specimen; Rhenish Mountains, Oberscheld (Grube Volpertseiche); late Givetian (Red Ironstone); Kauth Coll.; MB. C. 30424 • 1 specimen; Rhenish Mountains, Oberscheld (Grube Volpertseiche); late Givetian (Red Ironstone); Koch Coll.; MB. C. 4291 • 1 specimen; Rhenish Mountains, Oberscheld (Sessacker); late Givetian (Red Ironstone); Dannenberg Coll.; MB. C. 30426 • 1 specimen; Rhenish Mountains, Oberscheld (Staatliche Grube); late Givetian (Red Ironstone); Hubach 1920 Coll.; MB. C. 4300 • 1 specimen; Rhenish Mountains, Oberscheld (Grube Königszug); late Givetian (Red Ironstone); Meuhsen 1855 Coll.; SMF. Mbg. 2324 • 1 specimen; Rhenish Mountains, Langenaubach; late Givetian (Red Ironstone); GZG 389 - 82.	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C9186647420C8950FDF65EAEFC70C283.taxon	description	Description Nine specimens are selected for description and illustration: Holotype MB. C. 4289.1: rather poorly preserved, worn specimen with 43 mm conch diameter in haematitic ironstone. Shell ornament barely visible (Fig. 8 D). MB. C. 4291: fully septate, incomplete but rather well-preserved specimen with 61 mm conch diameter in haematitic limestone, phragmocone filled with white calcite (Fig. 8 A). MB. C. 4290: rather well-preserved specimen with 50 mm conch diameter in haematitic ironstone; fully covered with shell (Fig. 8 B). MB. C. 4289.2: moderately preserved specimen with 42 mm diameter in haematitic ironstone, phragmocone filled with white calcite (Fig. 8 E). MB. C. 5576: incomplete specimen with 45 mm diameter in haematitic limestone; shell surface wellvisible (Fig. 8 C). MB. C. 30421.1: rather well-preserved, laterally deformed specimen with 36 mm conch diameter in reddish-ochre limestone; almost fully covered with shell. MB. C. 30419: sectioned specimen with 60 mm conch diameter in haematitic limestone (Fig. 9 A). Specimen SMF. Mbg. 2324, the holotype of “ Gephyroceras Kayseri ”, is a specimen with 58 mm diameter (Fig. 4 C). Specimen GZG 389 - 82, the invalid neotype of Ponticeras aequabile, is an incomplete specimen with about 105 mm conch diameter in haematitic limestone (Fig. 10). The material allows the study of conch geometry between 36 and 105 mm conch diameter. Only slight changes in proportions can be recognised in this growth interval (Fig. 9 A). The conch is always extremely discoidal and subevolute to evolute (ww / dm = 0.20 – 0.25; uw / dm = 0.39 – 0.47) with a weak tendency towards a wider umbilicus at a larger diameter. The whorl profile of the sectioned specimen MB. C. 30419 is always compressed (ww / wh = 0.64 – 0.70) with a broadly rounded or slightly flattened and oblique umbilical wall, a rounded umbilical margin, strongly converging flanks and a narrowly rounded venter. Rarely, as in specimen MB. C. 4290, there is a weak depression visible in the ventrolateral area (Fig. 8 B). The ornament is preserved in several specimens. In specimen MB. C. 4290 the shell is decorated with irregular coarse growth lines with a strongly biconvex course; the dorsolateral projection is low, the ventrolateral projection is very high and narrow and the ventral sinus is narrow and very deep. Specimen MB. C. 4291 shows three faint spiral lines in the middle flank area (Fig. 8 A). Several of the specimens, such as MB. C. 4291, possess a spiral ridge, of approximately 0.5 mm width, on the midflank parallel to the umbilical seem of the next volution. In specimen MB. C. 4290, such a ridge is only developed on the right side.	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C9186647420C8950FDF65EAEFC70C283.taxon	discussion	Remarks House in House & Ziegler (1977: 77: pl. 1 fig. 25) stated that the original specimen could not be traced and proposed a neotype from the Göttingen Collection (GZG 389 - 82), which was figured by Wedekind (1918: pl. 21 fig. 6). However, specimen MB. C. 4289.1 (Beyrich 1835 Coll.) is stored in the MfN collection; it was figured by Beyrich (1837: pl. 2 fig. 1) and is re-illustrated here in Fig. 8 D. As there were other specimens in the Beyrich collection, it is designated the lectotype here. Wedekind (1913) regarded specimens with a weakly applanate venter as belonging to P. aequabile var. nov. In a later paper, Wedekind (1918) introduced the new species “ Gephyroceras Kayseri ” (Fig. 4 D) that is characterised by a narrow, blunt venter but clearly shows the morphology of the lectotype of P. aequabile. Ponticeras aequabile differs from P. materni sp. nov., which also occurs in the Oberscheld assemblages, in the narrowly rounded venter, which is flattened in the latter species. Ponticeras aequabile is also distinguished from the other species of the genus by the closely rounded venter, which is either broadly rounded (P. lebedeffi, P. uralicum, P altaicum, P. uchtense, P. discoidale), flattened (P. auritum) or separated from the flanks by ventrolateral longitudinal grooves (P. tschernyschewi, P. domanicense, P. keyserlingi, P. regale).	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C91866474208894DFD0D5D8BFE02C847.taxon	description	urn: lsid: zoobank. org: act: 498 BFB 7 B-FB 0 D- 46 D 1 - 8 BE 5 - 89323 D 1 C 8628 Figs 11 – 12	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C91866474208894DFD0D5D8BFE02C847.taxon	diagnosis	Diagnosis Species of Ponticeras reaching about 80 mm conch diameter with thinly discoidal, subevolute conch at 5 mm dm (ww / dm ~ 0.45; uw / dm ~ 0.42), with extremely discoidal, subevolute conch at 15 mm dm (ww / dm ~ 0.32; uw / dm ~ 0.33) and with extremely discoidal, subevolute conch at 50 mm dm (ww / dm ~ 0.25; uw / dm ~ 0.40); coiling rate usually low to moderately high (WER = 1.70 – 1.85). Whorl profile depressed in early ontogeny (ww / wh ~ 1.40 at 5 mm dm) and compressed in late ontogeny (ww / wh ~ 0.70 at 50 mm dm); umbilical wall oblique and broadly rounded, venter weakly flattened. Growth lines fine, rhythmically strengthened to weak plications, strongly biconvex. Sometimes with a spiral ridge on the outer side of the umbilicus parallel to the umbilical seam. Suture line with V-shaped external lobe with strongly diverging flanks; median saddle comparatively high, E 2 lobe deep, pointed, ventrolateral saddle and lateral lobe rounded.	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C91866474208894DFD0D5D8BFE02C847.taxon	etymology	Etymology Named after Hans Matern to honour his work on Devonian ammonoids.	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C91866474208894DFD0D5D8BFE02C847.taxon	materials_examined	Material examined Holotype GERMANY • Rhenish Mountains, Oberscheld (Grube Volpertseiche); late Givetian (Red Ironstone); Koch Coll.; MB. C. 22159. Illustrated in Fig. 11 A. Paratypes GERMANY • 1 specimen; Rhenish Mountains, Dillenburg; late Givetian (Red Ironstone); Kauth Coll.; MB. C. 22178 • 1 specimen; Rhenish Mountains, Oberscheld (?); late Givetian (Red Ironstone); Dannenberg Coll.; MB. C. 4297 • 1 specimen; Rhenish Mountains, Oberscheld (?); late Givetian (Red Ironstone); MB. C. 22158 • 1 specimen; Rhenish Mountains, Oberscheld (Grube Prinzkessel; late Givetian (Red Ironstone); Zimmermann 1936 Coll.; MB. C. 22175 • 1 specimen; Rhenish Mountains, Oberscheld (Sessacker); late Givetian (Red Ironstone); Dannenberg Coll.; MB. C. 30427.	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C91866474208894DFD0D5D8BFE02C847.taxon	description	Description Five specimens are selected for description and illustration: MB. C. 22159: incomplete but rather well-preserved specimen with 49 mm conch diameter in haematitic ironstone (Fig. 11 A). MB. C. 22175: moderately preserved specimen with 38 mm conch diameter in haematitic ironstone; the last quarter of the last volution belongs to the body chamber (Fig. 11 B). MB. C. 22178: well-preserved specimen with 25 mm conch diameter in haematitic limestone (Fig. 11 C). MB. C. 22158: specimen with 68 mm conch diameter in micritic haematite-rich limestone; cut for a cross section (Fig. 12 A). MB. C. 4297: incomplete specimen with approximately 80 mm conch diameter in micritic haematite-rich limestone. Holotype MB. C. 22159 is, at 49 mm conch diameter, extremely discoidal and subevolute (Fig. 11 A); the whorl profile shows a flattened, oblique umbilical wall, a rounded umbilical margin, weakly convergent flanks with a faint longitudinal ventrolateral depression and a rounded venter that is separated from the flanks by a weakly angular shoulder. The shell ornament is not well-preserved, but it appears that growth lines are fine and only strengthened rhythmically on the umbilical wall. The penultimate whorl shows very weak, short plications on the umbilical margin. Only a small portion of the ventral suture line is visible in the specimen; it shows the shape of the external lobe typical for Ponticeras. Paratype MB. C. 22175 has an extremely discoidal and subevolute conch with moderate coiling rate at 38 mm diameter; the whorl profile is compressed with oblique, broadly rounded umbilical wall that continues into the broadly rounded umbilical margin (Fig. 11 B). The flanks are subparallel and separated from the narrowly rounded venter by a weakly angular ventrolateral shoulder. The venter becomes subacute during the last volution. Few shell remains show biconvex growth lines that form a very high, narrow ventrolateral projection and a deep ventral sinus. The suture line has a V-shaped external lobe with a median saddle reaching almost half of the height of the lobe depth. The ventrolateral saddle is rounded; the lateral lobe reaches only 60 % of the E lobe depth and is broadly rounded (Fig. 12 B). The smaller paratype MB. C. 22178 with 25 mm conch diameter does not show the suture line, species assignment is thus not completely clear. However, it shows the shell ornament well-preserved with strongly concavo-convex growth lines, which form a high linguiform ventrolateral salient. As in the holotype, the growth lines are strengthened rhythmically on the umbilical wall and the umbilical margin has weak plications (Fig. 11 C). The specimens allow the study of a growth interval between 25 and nearly 60 mm diameter. The material is somewhat variable with respect to the shape of the whorl profile, which in specimens MB. C. 22159 and MB. C. 22158 (the sectioned one) has a slightly flattened, oblique umbilical wall and a more pronounced umbilical margin when compared with specimen MB. C. 4297. The shape of the venter also shows some variation; it is more strongly flattened in specimen MB. C. 22158 (Fig. 12 A) than in specimen MB. C. 22159 (Fig. 11 A). All of the specimens show the shell ornament, which consists of very fine but rhythmically strengthened growth lines. These have a biconvex course with a low dorsolateral projection, a wide and shallow lateral sinus, a high and narrow ventrolateral projection and a deep ventral sinus. In the immature stage between about 15 and 30 mm diameter, there are weak and short radial plications visible on the umbilical margin. In specimen MB. C. 22158, a faint spiral ridge accompanies the umbilical seam. Specimen MB. C. 22158 was sectioned and allows the study of conch geometry from the initial stage up to 68 mm conch diameter (Fig. 12 A). The ontogenetic trajectories of the cardinal conch parameters are strikingly different: (1) The ww / dm and the ww / wh ratios are nearly monophasic with nearly continuously decreasing values; between 1 and 68 mm conch diameter, the ww / dm ratio decreases from 0.80 to 0.24 and the ww / wh ratio from nearly 2.00 to 0.75. (2) The uw / dm trajectory is triphasic with early ontogenetic increase from 0.32 to 0.43 between 1 and 4.5 mm dm, followed by a decrease to 0.33 at 16 mm dm and an adult re-increase to 0.40 at 40 mm. The umbilical ratio then remains at this value. (3) The WER trajectory is also triphasic with an early juvenile decrease from 2.00 at 1 mm dm to 1.73 at 2 mm dm, followed by an accelerated increase to a maximum value of 2.06 at 16 mm dm and a terminal decrease to around 1.70 in the largest stage. The whorl profile is crescent-shaped in the early juvenile stage up to 2 mm diameter and then becomes increasingly compressed. At about 10 mm conch diameter, the ww / wh ratio becomes lower than 1.00. Already at 8 mm diameter, the umbilical wall becomes very flat and connects with the preceding whorl in a very small angle. At 22 mm diameter, the umbilical wall is weakly incurved, a character that is maintained until the terminal stage. The venter is narrowly rounded at 30 mm diameter, but in the last one and a half whorls, it becomes flattened and gets bordered from the flanks by a pronounced, subangular ventrolateral shoulder.	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C91866474208894DFD0D5D8BFE02C847.taxon	discussion	Remarks Ponticeras materni sp. nov. is similar to P. aequabile but differs in the flattened venter, which is narrowly rounded in the latter species. Ponticeras materni sp. nov. differs from the other species with a flattened venter (P. auritum) in the much wider umbilicus (uw / dm = 0.35 – 0.40 in P. materni sp. nov. but only ~ 0.20 in P. auritum).	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C91866474214894CFE5C58AEFD9BC693.taxon	type_taxon	Type species Timanites meridionalis Petter, 1959 (original designation).	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C91866474214894CFE5C58AEFD9BC693.taxon	diagnosis	Diagnosis Genus of the family Taouzitidae with extremely discoidal, subinvolute to involute conch; venter subacute or acute in the adult stage. With single ventrolateral grooves. Suture line with wide external lobe, high median saddle, V-shaped E 2 lobe, V-shaped lateral lobe and shallow, rounded umbilical lobes. Suture line formula (E 2 E 1 E 2) L U 2 U 4: U 3 U 1 I.	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C91866474214894CFE5C58AEFD9BC693.taxon	discussion	Remarks Darkaoceras (with subacute venter and four umbilical lobes) is morphologically intermediate between Mzerrebites (with narrowly rounded venter and three umbilical lobes) and Taouzites (with sharp venter and up to eight umbilical lobes).	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C91866474214894CFD155A60FB95C3FB.taxon	diagnosis	Diagnosis Gephuroceratoidea with sutural formula (E 2 E 1 E 2) L U 2: U 3 U 1 I to (E 2 E 1 E 2) L U 2 U 4 U 6 U 8: U 7 U 5 U 3 U 1 I; lateral saddle narrow, rounded; lateral lobe simple, rounded or acute.	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C91866474214894CFD155A60FB95C3FB.taxon	discussion	Remarks The lineage of the family Taouzitidae partly resembles the morphological evolution of two Frasnian lineages of gephuroceratids, the koenenitids and the beloceratoids (e. g., Korn 2001). However, the major difference between the taouzitids and the beloceratids is that in the taouzitids the external lobe retained its original shape, whereas in the beloceratids there was a proliferation of both the umbilical lobes and the external lobes. In the koenenitids, the external lobe remained tripartite and there was the development of only three umbilical lobes in the terminal genus Timanites.	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C918664742148949FDCC5C51FEFEC477.taxon	description	Figs 13 – 14	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C918664742148949FDCC5C51FEFEC477.taxon	diagnosis	Diagnosis Species of Darkaoceras reaching about 60 mm conch diameter with extremely discoidal, subinvolute conch between 30 and 50 mm dm (ww / dm = 0.25 – 0.30; uw / dm = 0.15 – 0.25). Whorl cross section strongly compressed (ww / wh = 0.45 – 0.60); venter acute with pronounced keel. Growth lines fine, bundled around the umbilicus, strongly biconvex with moderately high dorsolateral projection and very high and narrow ventrolateral projection; ventrolateral shoulder with weak spiral groove. Suture line with high median saddle, V-shaped prongs of the E lobe, V-shaped L lobe, and shallow and rounded U 2 lobe.	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C918664742148949FDCC5C51FEFEC477.taxon	materials_examined	Material examined Holotype GERMANY • Rhenish Mountains, Oberscheld (Westfeld der Grube Königszug, Firste der 120 – 150 m-Sohle); late Givetian (Red Ironstone); Ahlburg Coll.; MB. C. 3652. Illustrated by Matern (1931: pl. 2 fig. 10 a, d), re-illustrated here in Fig. 13 C. Paratypes GERMANY • 10 specimens; Rhenish Mountains, Oberscheld (Westfeld der Grube Königszug, Firste der 120 – 150 m-Sohle); late Givetian (Red Ironstone); Ahlburg Coll.; MB. C. 3629, MB. C. 3633, MB. C. 3635, MB. C. 3645, MB. C. 3649, MB. C. 3650, MB. C. 3651, MB. C. 3657, MB. C. 3658, MB. C. 3665. Additional material GERMANY • 1 specimen; Rhenish Mountains, Nanzenbach (Grube Königszug); late Givetian (Red Ironstone); Dannenberg Coll.; MB. C. 30428 • 1 specimen; Rhenish Mountains, Oberscheld; late Givetian (Red Ironstone); Hubach Coll.; MB. C. 3616 • 1 specimen; Rhenish Mountains, Oberscheld (Grube Gründchesseite); late Givetian (Red Ironstone); Lotz 1901 – 1902 Coll.; MB. C. 22153 • 1 specimen; Rhenish Mountains, Oberscheld (Grube Prinzkessel); late Givetian (Red Ironstone); Fremdling Coll.; MB. C. 30429.	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C918664742148949FDCC5C51FEFEC477.taxon	description	Description Five specimens are selected for description and illustration: MB. C. 3658: well-preserved, slightly deformed specimen with 48 mm conch diameter in iron-rich micritic limestone; largely covered with shell (Fig. 13 A). MB. C. 3635: laterally deformed specimen with 48 mm conch diameter in iron-rich micritic limestone; largely covered with shell (Fig. 13 B). MB. C. 3633: deformed specimen with about 50 mm conch diameter in iron-rich micritic limestone; cut for a cross section but inner whorls not preserved. Outer suture line visible (Fig. 14 A). Holotype MB. C. 3652: rather poorly preserved, slightly deformed specimen with about 42 mm conch diameter in iron-rich micritic limestone; specimen suffered from rough preparation (Fig. 13 C). MB. C. 30429: incomplete, slightly deformed specimen with 24 mm conch diameter in iron-rich sparitic limestone; partly covered with shell (Fig. 13 D). The two specimens MB. C. 3658 and MB. C. 3635, both with about 48 mm conch diameter, have an extremely discoidal and subinvolute conch with very high coiling rate and strongly compressed whorl profile (Fig. 13 A – B). The umbilical wall is very shallow and the flanks converge towards the subacute venter. The ornament consists of fine growth lines with biconvex course; the ventrolateral projection is high and narrow. Faint short riblets are present around the umbilicus. The suture line of specimen MB. C. 3633 has a wide external lobe; this is subdivided by a median saddle that has a height of two thirds of the external lobe depth (Fig. 14 A). The prongs of the external lobe are slightly asymmetric and V-shaped. On the flank follows a V-shaped lateral lobe and, on the umbilial margin, a broadly rounded umbilical lobe.	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C918664742148949FDCC5C51FEFEC477.taxon	discussion	Remarks The specimens from Dillenburg are quite large; smaller specimens from 3 up to 38 mm conch diameter were described by Bockwinkel et al. (2013 b) from Hagen-Herbeck, northern margin of the Rhenish Mountains. A similar species to D. galeatum is D. meridionale, but this species differs in having slightly thicker inner whorls. D. velox Bockwinkel, Becker & Ebbighausen, 2013 also differs by the broader inner whorls.	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C918664742118949FD015F2CFB85C75C.taxon	type_taxon	Type species Pharciceras taouzensis Termier & Termier, 1950 (original designation).	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C918664742118949FD015F2CFB85C75C.taxon	diagnosis	Diagnosis Genus of the family Taouzitidae with extremely discoidal, involute conch; venter acute in the adult stage. With single ventrolateral grooves in the juvenile and pre-adult stage. Suture line with wide external lobe, high median saddle, lanceolate E 2 lobe, V-shaped lateral lobe and acute or rounded umbilical lobes. Suture line formula formula (E 2 E 1 E 2) L U 2 U 4 U 6 U 8: U 7 U 5 U 3 U 1 I.	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C918664742118949FD015F2CFB85C75C.taxon	discussion	Remarks Taouzites presents the morphological end member of an evolutionary series in the Givetian, which, starting from simple gephuroceratids, is characterised by a flattening of the conch with a sharpening venter and simultaneous proliferation of the umbilical lobes (Korn 2001).	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C918664742118947FDE95C01FEBBC2F8.taxon	description	Fig. 15	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C918664742118947FDE95C01FEBBC2F8.taxon	diagnosis	Diagnosis Species of Taouzites reaching about 60 mm conch diameter with extremely discoidal, involute conch at 30 mm dm (ww / dm ~ 0.30; uw / dm ~ 0.10); coiling rate very high (WER ~ 2.40). Whorl profile strongly compressed (ww / wh ~ 0.55); umbilical wall oblique and flattened, venter sharply acute. Growth lines very fine, strongly biconvex. Suture line with wide external lobe, high, narrow median saddle, pointed E 2 and E 4 lobes and rounded lateral and umbilical saddles and lobes.	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C918664742118947FDE95C01FEBBC2F8.taxon	materials_examined	Material examined Holotype GERMANY • Rhenish Mountains, Oberscheld (“ Tiefe Grube ”); late Givetian (Red Ironstone); Etzold 1910 Coll.; MB. C. 3664. Illustrated by Matern (1931: pl. 2 fig. 8), re-illustrated here in Fig. 15 A. Paratype GERMANY • Rhenish Mountains, Oberscheld (“ Tiefe Grube ”); late Givetian (Red Ironstone); Etzold 1910 Coll.; MB. C. 30430. Additional material GERMANY • 1 specimen; Rhenish Mountains, Oberscheld (Grube Königszug); late Givetian (Red Ironstone); Krecke 1903 Coll.; MB. C. 22193.	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C918664742118947FDE95C01FEBBC2F8.taxon	description	Description Two specimens are selected for description and illustration: Holotype MB. C. 3664: slightly deformed specimen with 29 mm conch diameter in tuffitic ironstone (Fig. 15 A). MB. C. 22193: fragmentary specimen with 56 mm diameter in haematitic, micritic limestone. Holotype MB. C. 3664 has a thinly discoidal and involute conch with very high coiling rate (Fig. 15 A). The whorl profile strongly compressed; the umbilical wall is very shallow and the flanks converge towards the acute venter that possesses a fine keel. Rather coarse growth lines with biconvex course are visible on the flanks; they extend with a low dorsolateral projection and a high, narrow ventrolateral projection. The suture line possesses a wide, parallel-sided external lobe, a V-shaped lateral lobe, a small and V-shaped U 2 lobe and a shallow, rounded U 4 lobe (Fig. 15 B).	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C918664742118947FDE95C01FEBBC2F8.taxon	discussion	Remarks Taouzites acutus resembles T. taouzensis from the Anti-Atlas but, at a comparable diameter (30 mm) the conch dimensions are different in T. taouzensis with ww / dm = 0.25, uw / dm = 0.15, ww / wh = 0.45, WER = 2.60.	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C9186647421F8947FDE65FFDFE5BC842.taxon	type_taxon	Type species Goniatites lamellosus Sandberger & Sandberger, 1851 (original designation).	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C9186647421F8947FDE65FFDFE5BC842.taxon	diagnosis	Diagnosis Genus of the family Koenenitidae with extremely discoidal, subinvolute to involute conch; venter rounded in all stages. Suture line with wide external lobe, moderately high median saddle, narrowly V-shaped E 2 lobe, U-shaped or V-shaped lateral lobe and rounded umbilical lobes. Suture line formula (E 2 E 1 E 2) L U 2: U 1 I.	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C9186647421F8947FDE65FFDFE5BC842.taxon	discussion	Remarks Koenenites is the only genus of the family Koenenitidae in which the conch has a rounded venter. Koenenites, along with Hoeninghausia, also has the simplest suture line in the family with only two umbilical lobes.	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C9186647421F8947FDA35990FB64C4CB.taxon	diagnosis	Diagnosis Family of the superfamily Gephuroceratoidea with discoidal conch with moderately narrow to closed umbilicus; rounded venter in early species but acute venter in late species. Growth lines with high ventrolateral projection. Sutural evolution with proliferation of umbilical lobes during phylogeny. Sutural formula (E 2 E 1 E 2) L U 2: U 1 I to (E 2 E 1 E 2) L U 2: U 3 U 1 I; lateral lobe simple, usually V-shaped.	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C9186647421E8942FE795A60FA58C3C9.taxon	description	Figs 16 – 18	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C9186647421E8942FE795A60FA58C3C9.taxon	diagnosis	Diagnosis Species of Koenenites reaching about 90 mm conch diameter with thickly discoidal, evolute conch at 5 mm dm (ww / dm ~ 0.50; uw / dm ~ 0.45); coiling rate moderate (WER ~ 1.85); with thinly discoidal, subinvolute conch at 20 mm dm (ww / dm ~ 0.40; uw / dm ~ 0.28); with extremely discoidal, subinvolute conch at 75 mm dm (ww / dm ~ 0.25; uw / dm ~ 0.23); coiling rate moderate at 5 mm dm (WER ~ 1.85) and very high above 30 mm dm (WER ~ 2.40). Whorl profile compressed (ww / wh ~ 0.50) in the adult stage; umbilical wall steep and rounded, venter rounded. Growth lines lamellar, strongly biconvex with very narrow, high ventrolateral projection. Suture line simple, with V-shaped external lobe, high median saddle, pointed asymmetrical prongs of the E lobe, slightly asymmetrically rounded lateral saddle and pointed L lobe.	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C9186647421E8942FE795A60FA58C3C9.taxon	materials_examined	Material examined Lectotype GERMANY • Rhenish Mountains, Nanzenbach; early Frasnian (Red Ironstone); Wiesb. 40 a. Illustrated by Sandberger & Sandberger (1850 – 1856: pl. 8 fig. 1) and Korn & Klug (2002: text-fig. 108 a), reillustrated here in Fig. 16 A. Paralectotype GERMANY • Rhenish Mountains, Nanzenbach; early Frasnian (Red Ironstone); Wiesb. 40 b. Illustrated by Sandberger & Sandberger (1850 – 1856: pl. 8 fig. 1 a-c) and Korn & Klug (2002: text-fig. 108 b), reillustrated here in Fig. 16 D. Additional material GERMANY • 4 specimens; Rhenish Mountains, Oberscheld (Grube Anna); early Frasnian (Red Ironstone); Koch Coll.; MB. C. 4306.1, MB. C. 34306.2, MB. C. 4306.3, MB. C. 22184 • 1 specimen; Rhenish Mountains, Oberscheld (Grube Königszug, 120 m-Sohle); early Frasnian (Red Ironstone); MB. C. 22201 • 2 specimens; Rhenish Mountains, Oberscheld (Grube Rinkenbach); early Frasnian (Red Ironstone); Dannenberg Coll.; MB. C. 22183, MB. C. 22189 a – b • 1 specimen; Rhenish Mountains, Oberscheld (Sessacker); early Frasnian (Red Ironstone); Dannenberg Coll.; MB. C. 30431 • 2 specimens; Rhenish Mountains, Oberscheld (Staatliche Grube); early Frasnian (Red Ironstone); Hubach 1913 Coll.; MB. C. 4303.2, MB. C. 4303.3.	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C9186647421E8942FE795A60FA58C3C9.taxon	description	Description Eight specimens are selected for description and illustration: Lectotype Wiesb. 40 a: incomplete specimen with 65 mm conch diameter in haematitic ironstone (Fig. 16 A). Paratype Wiesb. 40 b: incomplete specimen with about 50 mm conch diameter in haematitic ironstone (Fig. 16 D). MB. C. 22184: incomplete specimen with 73 mm conch diameter in haematitic iron ore, the last whorl is partly crushed (Fig. 17 A). MB. C. 22183: incomplete specimen with 53 mm conch diameter in haematitic ironstone (Fig. 17 B). MB. C. 22201: sectioned specimen with 77 mm conch diameter in haematite ore (Fig. 18 A). MB. C. 4306.1: well-preserved, complete steinkern specimen with 36 mm conch diameter in haematitic ironstone (Fig. 17 C). MB. C. 4306.2: well-preserved, complete specimen with 25 mm conch diameter in haematitic ironstone, ornament perfectly preserved (Fig. 17 D). MB. C. 4306.3: well-preserved, complete specimen with 20 mm conch diameter in haematitic ironstone, ornament perfectly preserved (Fig. 17 E). The three specimens MB. C. 4306.1, MB. C. 4306.2 and MB. C. 4306.3 allow the study of conch proportions and ornament between 19 and 36 mm diameter (Fig. 17 C-E). They are similar in shape with a weak ontogenetic trend towards a slenderer conch (ww / dm decreasing from 0.35 to 0.29). They show an oblique, broadly convex umbilical wall and flanks that converge slowly towards the narrowly rounded venter. The ornament shows lamellar growth lines, which in the two smaller specimens MB. C. 4306.2 and MB. C. 4306.3 are particularly well-preserved; they extend with a low dorsolateral projection, a deep and wide lateral sinus and a very narrow, very high linguiform ventrolateral projection across the flanks and then turn back to form a narrow, very deep ventral sinus. The larger specimens MB. C. 22183 (53 mm dm) and MB. C. 22184 (73 mm dm) are thinly discoidal and subinvolute with a compressed whorl profile; the umbilical wall is steep and the flanks converge towards the narrowly rounded venter (Fig. 17 A – B). The ornament shows biconvex growth lines, which are fine on the inner flank and lamellar on the outer flank. They extend with a moderately high dorsolateral projection and a high and subangular ventrolateral projection. The external sinus is deep and semicircular. The suture line is partly visible in specimen MB. C. 22184, showing a V-shaped lateral lobe on the inner flank (Fig. 18 B). The sectioned specimen MB. C. 22201 (Fig. 18 A) shows significant ontogenetic changes in the conch parameters: (1) the ww / dm ratio has a nearly monophasic ontogeny with a rather continuous decrease from 0.75 at 1 mm dm to = 0.25 at 77 mm dm. (2) The ww / wh ratio has a similar course (from 2.05 to 0.50) but with more accelerated decrease between 3 and 10 mm dm. (3) The uw / dm ratio is conspicuously biphasic with a juvenile increase from 0.35 to 0.45 at 5 mm dm and an adult decrease to 0.23. (4) The coiling rate is also biphasic, but not parallel to the uw / dm ratio; the WER shows a juvenile decrease to 1.68 at 3.5 mm dm, followed by a decelerated increase with asymptotic approximation of a value of 2.40 at 30 mm dm (Fig. 18 C – F). The ontogeny of the whorl profile is rather simple with a continuous transformation of a depressed shape into a compressed shape; the value falls below a value of 1.00. Above this diameter, the whorl profile has a steep umbilical wall, a broadly rounded umbilical margin, moderately strong converging flanks and a rounded venter.	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C9186647421E8942FE795A60FA58C3C9.taxon	discussion	Remarks Matern (1931: 74, pl. 2 fig. 7) proposed a neotype from the Senckenberg Collection (specimen XI 329 a) and stated that the original specimen is missing. However, two syntypes figured by Sandberger & Sandberger (1850 – 1856) are preserved (specimens 40 a = old 62.11. / W. 15 a and 40 b = old 62.11. / W. 15 b) in the Sandberger collection, which is stored at the Wiesbaden Museum. House (1978: 48, pl. 7 fig. 5) designated specimen 40 a as the lectotype; it was illustrated by Sandberger & Sandberger (1850 – 1856: pl. 8 fig. 1) and is re-illustrated here (Fig. 16 A). Sandberger & Sandberger (1850 – 1856) described the two new species “ Goniatites sublamellosus ” and “ Goniatites lamellosus ”, which apparently are conspecific. Of these two, mostly “ G. lamellosus ” was refigured and is therefore here used as the valid species (despite the page priority of “ G. sublamellosus ”).	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C9186647421A8942FDB658A1FC78C57E.taxon	diagnosis	Diagnosis Family of the superfamily Beloceratoidea with sutural formula (E 2 E 1 E 2) L U: I; lateral saddle narrow, narrowly rounded to subacute; lateral lobe simple, rounded.	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C9186647421A8941FDF25E15FD1EC19B.taxon	type_taxon	Type species Clymenia (Cyrtoclymenia) Neapolitana Clarke, 1892 (original designation).	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C9186647421A8941FDF25E15FD1EC19B.taxon	diagnosis	Diagnosis Genus of the family Acanthoclymeniidae with extremely discoidal, subinvolute to subevolute conch; venter flattened or concave. Suture line with relatively narrow wide lobe, moderately high median saddle, V-shaped E 2 lobe, shallow and rounded lateral lobe. Suture line formula (E 2 E 1 E 2) L: U I.	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C9186647421A8941FDF25E15FD1EC19B.taxon	discussion	Remarks In the description of the type species as well as its assignment to a genus, it was erroneously assumed that it was a clymeniid; this error was corrected by House (1961) and the species was classified among the gephuroceratids, although in the genus Manticoceras. Acanthoclymenia is considered the stratigraphically earliest and morphologically simplest genus of the superfamily Beloceratoidea (Korn & Klug 2002). It still has a suture line of the early gephuroceratids (for example Ponticeras), consisting of a divided external lobe and a lateral, umbilical and internal lobe each. The genus is distinguished from the ponticeratids by the concave venter; a character that persists in subsequent forms of the Beloceratoidea.	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C91866474219897FFE5E5959FCDBC5BC.taxon	description	Figs 19 – 20	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C91866474219897FFE5E5959FCDBC5BC.taxon	diagnosis	Diagnosis Species of Acanthoclymenia reaching about 40 mm conch diameter with extremely discoidal, subinvolute conch between 12 and 28 mm dm (ww / dm = 0.20 – 0.25; uw / dm ~ 0.28); coiling rate very high (WER increasing from 2.25 to 2.60). Whorl profile strongly compressed (ww / wh ~ 0.50); umbilical wall shallow and rounded, whorl profile pear-shaped, ventrolateral margin angular, venter flat or slightly concave. Growth lines very fine, strongly biconvex.	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C91866474219897FFE5E5959FCDBC5BC.taxon	materials_examined	Material examined Lectotype GERMANY • Rhenish Mountains, Oberscheld; early Frasnian (Red Ironstone); Wiesb. 36 a. Illustrated by Sandberger & Sandberger (1850 – 1856: pl. 6 fig. 3), re-illustrated by House in House & Ziegler (1977: pl. 3 figs 28 – 29) and here (Fig. 19). Additional material GERMANY • 1 specimen; Rhenish Mountains, Oberscheld (Eiserne Hand, Betagrube); early Frasnian (Red Ironstone); Trempel Coll.; MB. C. 30432 • 1 specimen; Rhenish Mountains, Oberscheld (Eiserne Hand, Grube Friedrich); early Frasnian (Red Ironstone); Kegel Coll.; MB. C. 3669 • 9 specimens; Rhenish Mountains, Oberscheld (Grube Anna); early Frasnian (Red Ironstone); Koch Coll.; MB. C. 22199.1, MB. C. 22199.2, MB. C. 22199.3, MB. C. 22200, MB. C. 30433.1, MB. C. 30433.2, MB. C. 30433.3 • 1 specimen; Rhenish Mountains, Oberscheld (Grube Sahlgrund, 205 m-Sohle); early Frasnian (Red Ironstone); MB. C. 30434 • 1 specimen; Rhenish Mountains, Oberscheld (Grube Stillingseisenzug); early Frasnian (Red Ironstone); Möbus 1901 Coll.; MB. C. 30435 • 1 specimen; Rhenish Mountains, Oberscheld (Grube Ypsilanta); early Frasnian (Red Ironstone); Etzold 1910 Coll.; MB. C. 30436 • 1 specimen; Rhenish Mountains, Oberscheld (Grube Ypsilanta); early Frasnian (Red Ironstone); Lotz 1901 – 1902 Coll.; MB. C. 30437.	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C91866474219897FFE5E5959FCDBC5BC.taxon	description	Description Six specimens are selected for description and illustration: Lectotype Wiesb. 36 a: fully septate specimen with 16 mm conch diameter in haematitic ironstone (Fig. 19). MB. C. 22199.1: rather well-preserved specimen with 28 mm conch diameter in haematitic iron ore; largely covered with shell (Fig. 20 A). MB. C. 22199.2: well-preserved, slightly deformed specimen with 14 mm conch diameter in haematitic iron ore; largely covered with shell (Fig. 20 D). MB. C. 30433.1: well-preserved, slightly deformed specimen with 27 mm conch diameter in haematitic iron ore; largely covered with shell (Fig. 20 B). MB. C. 30433.2: well-preserved, slightly deformed specimen with 22 mm conch diameter in haematitic iron ore; largely covered with shell (Fig. 20 C). MB. C. 30433.3: fragmentary specimen co-occurring in a block of haematitic iron ore together with a specimen Crickites Wedekind, 1913. The specimens MB. C. 22199.2 (14 mm dm), MB. C. 30433.2 (22 mm dm), MB. C. 30433.1 (27 mm dm) and MB. C. 22199.1 (28 mm dm) show that, during this growth interval, no significant changes in the conch proportions can be recognised (Fig. 20). The conchs are extremely discoidal and subinvolute with very high coiling rate; the whorl profile is compressed. The umbilical wall is very shallow; the flanks converge towards the angular ventrolateral shoulder, the outer flanks are weakly incurved and the venter is flat. The ornament consists of fine growth lines with biconvex course; they extend with a very low dorsolateral projection on the umbilical margin and a high and narrow ventrolateral projection across the flanks. Faint short riblets are present around the umbilicus.	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C91866474219897FFE5E5959FCDBC5BC.taxon	discussion	Remarks When Sandberger & Sandberger (1850 – 1856) described the new species Goniatites forcipifer, they did not make it clear whether the species name (“ carrying a fire tong ”) was a noun or an adjective. Since such species names are usually considered adjectives, we here decline it to the feminine form. Acanthoclymenia forcipifera differs from the second species of the genus from Oberscheld, A. planorbis (Sandberger & Sandberger, 1851), in the much narrower umbilicus at 12 mm conch diameter (uw / dm ~ 0.30 in A. forcipifera but ~ 0.50 in A. planorbis).	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C91866474227897DFE465D61FE55C436.taxon	description	Figs 21 – 22	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C91866474227897DFE465D61FE55C436.taxon	diagnosis	Diagnosis Species of Acanthoclymenia reaching about 30 mm conch diameter with small, extremely discoidal, evolute conch between 12 and 32 dm (uw / dm decreasing from ~ 0.50 to ~ 0.45). Whorl profile compressed; umbilical wall shallow and rounded, whorl profile pear-shaped, ventrolateral margin angular, venter flat. Growth lines very fine, strongly biconvex.	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C91866474227897DFE465D61FE55C436.taxon	materials_examined	Material examined Lectotype GERMANY • Rhenish Mountains, Oberscheld; middle Frasnian (Red Ironstone); Wiesb. 46 a. Illustrated by Sandberger & Sandberger (1850 – 1856: pl. 9 fig. 3 a); re-illustrated here (Fig. 21 A). Paralectotype GERMANY • 1 specimen; Rhenish Mountains, Oberscheld; middle Frasnian (Red Ironstone); Wiesb. 46 b. Illustrated by Sandberger & Sandberger (1850 – 1856: pl. 9 fig. 3) re-illustrated here (Fig. 21 B). Additional material GERMANY • 1 specimen; Rhenish Mountains, Oberscheld (Grube Königszug); middle Frasnian (Red Ironstone); Kauth Coll.; MB. C. 30438 • 1 specimen; Rhenish Mountains, Oberscheld; middle Frasnian (Red Ironstone); Koch Coll.; MB. C. 30439.	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C91866474227897DFE465D61FE55C436.taxon	description	Description Four specimens are selected for description and illustration: Lectotype Wiesb. 46 a: incomplete specimen with 32 mm conch diameter in haematitic ironstone (Fig. 21 A). Paralectotype Wiesb. 46 b: incomplete specimen with 22 mm conch diameter in haematitic ironstone (Fig. 21 B). MB. C. 30438: slab and counterslab with two specimens (13 and 7 mm conch diameter) co-occuring with Mesobeloceras kayseri in haematite ore (Fig. 22 A). MB. C. 30439: moderately well-preserved specimen with 12 mm conch diameter in haematitic iron ore (Fig. 22 B). The specimens contribute only little to our knowledge of the species. All are embedded on rock slabs (Fig. 22), which prevents precise measurement of the whorl width, but it is clear that the conch is extremely discoidal. It is also clear that the whorl profile is pear-shaped with a rounded umbilical wall, convex flanks, a subangular ventrolateral shoulder and a flattened venter. The umbilicus has nearly exactly half the value of the conch diameter.	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
C91866474227897DFE465D61FE55C436.taxon	discussion	Remarks Acanthoclymenia planorbis differs from the other species of the genus from Oberscheld, A. forcipifera, in the much wider umbilicus at 12 mm conch diameter (uw / dm ~ 0.50 in A. planorbis but ~ 0.30 in A. forcipifera).	en	Korn, Dieter, Bockwinkel, Jürgen (2022): The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea). European Journal of Taxonomy 823: 10-47, DOI: 10.5852/ejt.2022.823.1811, URL: http://zoobank.org/d5ac626b-4a10-4cd9-b77b-6d7efe8d180e
