A new ammonoid fauna from theGattendorfia-Eocanites Genozone of the Anti-Atlas (Early Carboniferous; Morocco)

From the eastern part of the Tafilalt (Anti-Atlas, Morocco), rich assemblages of ammonoids of the Gattendorfia-Eocanites Genozone are described. The detailed investigation of an outcrop near Mfis in the south-eastern Tafilalt yielded a diverse fauna with 24 species, of which 13 are new. The genus Weyerella n. gen. is newly erected with Weyerella protecta n. sp. as type species. Furthermore, the following new species are described: Paragattendorfia aboussalamae n. sp., Acutimitoceras hollardi n. sp., Acutimitoceras posterum n. sp., Acutimitoceras mfisense n. sp., Acutimitoceras occidentale n. sp., Imitoceras oxydentale n. sp., Kazakhstania nitida n. sp., Zadelsdorfia debouaaensis n. sp., Weyerella minor n. sp., Eocanites simplex n. sp., Eocanites rtbeckeri n. sp., and Eocanites dkorni n. sp. The state of preservation of the ammonoids as limonitic steinkern specimens permits a detailed study of sutures and conch ontogeny.Aus dem östlichen Tafilalt (Anti-Atlas, Marokko) wird eine Ammonoideen-reiche Abfolge aus der Gattendorfia-Eocanites Genus-Zone beschrieben. Ein im Detail untersuchtes Profil bei Mfis hat eine individuenreiche und diverse pelagische Fauna mit 24 Arten geliefert, von denen 13 neu sind. Die Gattung Weyerella n. gen. wird mit Weyerellaprotecta n. sp. als Typusart aufgestellt. Weitere neue Arten sind: Paragattendorfiaaboussalamae n. sp., Acutimitocerashollardi n. sp., Acutimitocerasposterum n. sp., Acutimitocerasmfisense n. sp., Acutimitocerasoccidentale n. sp., Imitocerasoxydentale n. sp., Kazakhstanianitida n. sp., Zadelsdorfiadebouaaensis n. sp., Weyerellaminor n. sp., Eocanitessimplex n. sp., Eocanitesrtbeckeri n. sp. und Eocanitesdkorni n. sp. Die in Limonit erhaltenen Steinkerne erlauben eine Detailuntersuchung der Lobenlinien und der Gehäuse-Ontogenie.doi:10.1002/mmng.20060000

The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea)

The ammonoids of the suborder Gephuroceratina from the Roteisenstein (Red Ironstone) Formation of the area around Dillenburg (eastern Rhenish Mountains) are revised, mainly based on historical collections stored in the Museum für Naturkunde, Berlin. The new species Ponticeras materni sp. nov. is described and the species Pseudoprobeloceras pernai (Wedekind, 1918), Pseudoprobeloceras applanatum (Wedekind, 1918), Ponticeras aequabile (Beyrich, 1837), Darkaoceras galeatum (Matern, 1931), Taouzites acutus (Matern, 1931), Koenenites lamellosus (Sandberger & Sandberger, 1851), Acanthoclymenia forcipifera (Sandberger & Sandberger, 1851) and Acanthoclymenia planorbis (Sandberger & Sandberger, 1851) are revised. The stratigraphic distribution of the genera is discussed; they are assigned to three assemblages: (1) Pseudoprobeloceras pernai Zone (latest Givetian; genera Pseudoprobeloceras, Ponticeras, Darkaoceras and Taouzites), (2) Koenenites lamellosus Zone (early Frasnian, containing Koenenites lamellosus and Acanthoclymenia forcipifera) and (3) Mesobeloceras kayseri Zone (middle Frasnian, containing Acanthoclymenia planorbis)

The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea)

The ammonoids of the suborder Gephuroceratina from the Roteisenstein (Red Ironstone) Formation of the area around Dillenburg (eastern Rhenish Mountains) are revised, mainly based on historical collections stored in the Museum für Naturkunde, Berlin. The new species Ponticeras materni sp. nov. is described and the species Pseudoprobeloceras pernai (Wedekind, 1918), Pseudoprobeloceras applanatum (Wedekind, 1918), Ponticeras aequabile (Beyrich, 1837), Darkaoceras galeatum (Matern, 1931), Taouzites acutus (Matern, 1931), Koenenites lamellosus (Sandberger &amp; Sandberger, 1851), Acanthoclymenia forcipifera (Sandberger &amp; Sandberger, 1851) and Acanthoclymenia planorbis (Sandberger &amp; Sandberger, 1851) are revised. The stratigraphic distribution of the genera is discussed; they are assigned to three assemblages: (1) Pseudoprobeloceras pernai Zone (latest Givetian; genera Pseudoprobeloceras, Ponticeras, Darkaoceras and Taouzites), (2) Koenenites lamellosus Zone (early Frasnian, containing Koenenites lamellosus and Acanthoclymenia forcipifera) and (3) Mesobeloceras kayseri Zone (middle Frasnian, containing Acanthoclymenia planorbis).</p

Fig. 8 in Early Carboniferous nautiloids from the Central Sahara, southern Algeria

Fig. 8. Stroborineceras felis gen. et sp. nov., holotype MB.C.30454 (Korn et al. 2002 Coll.) from Oued Temertasset. A. Ventral and lateral views. B. Whorl profile. C. Suture line, at ww = 15.6 mm, wh = 12.7 mm. Scale bar units = 1 mm.Published as part of Korn, Dieter & Bockwinkel, Jürgen, 2022, Early Carboniferous nautiloids from the Central Sahara, southern Algeria, pp. 67-108 in European Journal of Taxonomy 831 on page 78, DOI: 10.5852/ejt.2022.831.1871, http://zenodo.org/record/688519

Fig. 11 in The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea)

Fig. 11. Ponticeras materni sp. nov. A. Holotype MB.C.22159 (Koch Coll.) from Oberscheld (Volpertseiche Mine). B. Paratype MB.C.22175 (Zimmermann 1936 Coll.) from Oberscheld (Prinzkessel Mine). C. Paratype MB.C.22178 (Kauth Coll.) from Dillenburg. Scale bar units = 1 mm.Published as part of &lt;i&gt;Korn, Dieter &amp; Bockwinkel, Jürgen, 2022, The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea), pp. 10-47 in European Journal of Taxonomy 823&lt;/i&gt; on page 26, DOI: 10.5852/ejt.2022.823.1811, &lt;a href="http://zenodo.org/record/6628057"&gt;http://zenodo.org/record/6628057&lt;/a&gt

Epitornoceras mithracoides

Epitornoceras mithracoides (Frech, 1888) Figs 6–7; Table 3 Goniatites (Tornoceras) mithracoides Frech, 1888: 30, pl. 2 fig. 1. Tornoceras (Epitornoceras) mithracoides – Frech 1902a: 174, text-fig. 2a; 1902b: 52, text-fig. 14b. Goniatites (Tornoceras) mithracoides – Miller 1938: 141, text-fig. 30d. Epitornoceras mithracoides – House 1978: 60, pl. 10 figs 2–3. — Korn & Klug 2002: 158. — Bockwinkel et al. 2013: 268, text-figs 11–12. — Bockwinkel & Korn 2015: 358, text-figs 9–10. non Epitornoceras mithracoides – House et al. 1985: 5, text-figs 5a–b. — Dzik 2002: text-fig. 50n–o. — Korn & Klug 2002: text-fig. 144t. — Bockwinkel et al. 2009: 65, text-figs 1–2; 2013b: 57, textfigs 4d, 58–59; 2015: 148, text-figs 31–32; 2017: 346, text-figs 34–35. Diagnosis Epitornoceras reaching about 200 mm conch diameter. Thinly discoidal and involute adult stage (ww/dm ~ 0.35; umbilicus closed at 50 mm dm); whorl profile compressed (ww/wh ~ 0.65 at 50 mm dm); whorl expansion rate high (WER ~ 2.20). Flanks weakly convex, convergent, umbilical margin pronounced in the juvenile stage but continuously rounded in the adult stage. Without any ventrolateral grooves. Suture line with broadly rounded, asymmetric adventive lobe with convergent flanks; width of the adventive lobe equals the lobe depth. Type material Lectotype GERMANY • Rhenish Mountains, Oberscheld (Volpertseiche Mine); late Givetian (Red Ironstone); designated by Bockwinkel et al. (2009); figured by Frech (1888: text-fig. 1b, 1β) and House (1978: textfigs 2–3), re-illustrated here in Fig. 7A; Koch Coll.; MB.C.469. Paralectotype GERMANY • Rhenish Mountains, Oberscheld (Volpertseiche Mine); late Givetian (Red Ironstone); figured by Frech (1888: text-fig. 1a, 1α), re-illustrated here in Fig. 7C; Koch Coll.; MB.C.470. Description Two specimens are selected for description and illustration. Lectotype (MB.C.469) Completely chambered specimen with 53 mm conch diameter in haematitic limestone; it represents the inner portion of a phragmocone of a much larger specimen (Figs 6, 7A). It is a disc-shaped involute conch about 53 mm in diameter (ww/dm = 0.35). It is widest at the closed umbilicus, from where the flanks converge to the narrowly rounded venter. No shell remains are preserved; the specimen is covered by remains of the septa of the following volution. The suture line was already correctly illustrated by Frech (1888); it shows (Fig. 6) a V-shaped external lobe and a very narrow, subacute ventrolateral saddle. The adventive lobe is weakly asymmetric and broadly rounded with distinctly divergent flanks (Fig. 7B). Paralectotype (MB.C.470) Fragment of a completely chambered specimen with an estimated phragmocone diameter of 100 mm haematitic limestone (Figs 6, 7C). It is part of a phragmocone at least 100 mm in diameter; the total diameter together with the body chamber may therefore have been about 200 mm. The shape of the body corresponds to that of the lectotype. The paralectotype does not bear any shell remains either. Remarks Both specimens from Dillenburg are quite large; smaller specimens up to 15 mm in diameter were described by Bockwinkel et al. (2013b) and Bockwinkel & Korn (2015). Epitornoceras mithracoides cannot really be confused with any other ammonoid species from the Rhenish Mountains because of the subacute ventrolateral saddle. Very similar forms have been reported from the Anti-Atlas of Morocco and identified as this species (Bockwinkel et al. 2009, 2013a, 2015, 2017). These specimens have a very similar conch form to the red ironstone specimens, but show a suture line with a considerably deeper adventive lobe characterised by nearly parallel flanks. The differences become clear when the suture lines are morphometrically recorded. Measured at half the depth of the adventive lobe, the width of this lobe is 100% of the lobe depth in E. mithracoides, but only about 75% in the North African specimens (Bockwinkel et al. 2009), which are described below as E. transmediterraneum. The shape of the umbilicus can be mentioned as a further criterion; the umbilical wall is evenly rounded in the adult stage in E. mithracoides, but it is obliquely flattened caused by an umbilical shell thickening in E. transmediterraneum, leading to a funnel-shaped umbilicus with a distinct umbilical edge of the internal mould.Published as part of Korn, Dieter & Bockwinkel, Jürgen, 2022, The tornoceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea), pp. 32-51 in European Journal of Taxonomy 806 on pages 40-43, DOI: 10.5852/ejt.2022.806.1699, http://zenodo.org/record/637396

Lentitornoceras materni Korn & Bockwinkel 2022, gen. et sp. nov.

Lentitornoceras materni gen. et sp. nov. urn:lsid:zoobank.org:act: 267ABA4A-0287-4DEA-B888-4D391FB8D96D Fig. 8; Table 4 Diagnosis Lentitornoceras gen. nov. reaching about 45 mm conch diameter. Extremely discoidal and involute adult stage (ww/dm ~ 0.25; umbilicus nearly closed at 30 mm dm); whorl profile strongly compressed (ww/ wh ~ 0.40); whorl expansion rate moderate (WER ~ 1.80). Flanks weakly convex, umbilical margin continuously rounded, venter very narrowly rounded. Ornament with lamellar, wide-standing biconvex growth lines. Type material Holotype GERMANY • Rhenish Mountains, Oberscheld; late Givetian (from a Red Ironstone block together with Pharciceras oberscheldense); Lotz 1901–1902 Coll.; illustrated in Fig. 8; MB.C.30413. Etymology After Hans Matern, to honour his studies on the ammonoids from the Dillenburg region. Description Only the holotype is available for description and illustration. It is a specimen of almost 30 mm diameter in iron-rich limestone, largely preserved with its shell (Fig. 8A). The shape is that of a flat lens; the ww/ dm ratio is less than 25%. The umbilicus is almost completely closed; it is bounded by a very shallow umbilical margin. The flanks are slightly convex and converge slightly to the very narrowly rounded venter. The shell bears widespread, lamellar-appearing growth lines, which are biconvex with distinct dorsolateral projection and higher ventrolateral projection across the flank; the ventral sinus is narrow and deep (Fig. 8C). The growth lines are coarser on the venter than on the flanks. The suture line is typically tornoceratid with a wide, asymmetric adventive lobe, a narrow ventrolateral saddle and a small external lobe (Fig. 8B). Remarks Lentitornoceras materni gen. et sp. nov. can hardly be confused with another species from the red ironstone because of its peculiar conch morphology. Tornoceratids from other localities and stratigraphic horizons usually have a much more broadly arched venter. A comparable form is the late Givetian ‘ Lobotornoceras bensaidi ’ (Bockwinkel et al. 2013a); however, this form has a suture line with a very shallow adventive lobe. Subfamily Aulatornoceratinae Becker, 1993 Diagnosis Subfamily of the family Tornoceratidae with compressed conch, umbilicus narrow to moderately wide. With distinct ventrolateral grooves. Ornament with biconvex growth lines with very high ventrolateral projection, often with coarse ribs. Sutural formula E A L I. Included genera Aulatornoceras Schindewolf, 1922; Truyolsoceras Montesinos, 1988; Polonoceras Dybczy&nacute;ski, 1913; Planitornoceras Becker, 1995; Armatites Becker, 1993; Paucitornoceras gen. nov. Subfamily Aulatornoceratinae Becker, 1993 Diagnosis Subfamily of the family Tornoceratidae with compressed conch, umbilicus narrow to moderately wide. With distinct ventrolateral grooves. Ornament with biconvex growth lines with very high ventrolateral projection, often with coarse ribs. Sutural formula E A L I. Included genera Aulatornoceras Schindewolf, 1922; Truyolsoceras Montesinos, 1988; Polonoceras Dybczy&nacute;ski, 1913; Planitornoceras Becker, 1995; Armatites Becker, 1993; Paucitornoceras gen. nov.Published as part of Korn, Dieter & Bockwinkel, Jürgen, 2022, The tornoceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea), pp. 32-51 in European Journal of Taxonomy 806 on pages 45-46, DOI: 10.5852/ejt.2022.806.1699, http://zenodo.org/record/637396

Epitornoceras Frech 1902

Genus Epitornoceras Frech, 1902 Type species Tornoceras (Tornoceras) mithracoides Frech, 1888; by original designation. Diagnosis Genus of the subfamily Tornoceratinae with compressed conch, umbilicus closed in the pre-adult stage but slightly opened in the juvenile stage. Usually without ventrolateral grooves. Ornament with biconvex growth lines, without ribs. Sutural formula E A L I; adventive lobe broadly rounded, asymmetric with steep dorsal flank; ventrolateral saddle narrow, subacute. Included species Tornoceras (Tornoceras) mithracoides Frech, 1888, Rhenish Mountains; Goniatites peracutus Hall, 1876, New York; Epitornoceras transmediterraneum sp. nov., Anti-Atlas. Remarks Epitornoceras differs from the other genera of the subfamily by the very narrow ventrolateral saddle of the suture line.Published as part of Korn, Dieter & Bockwinkel, Jürgen, 2022, The tornoceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea), pp. 32-51 in European Journal of Taxonomy 806 on page 40, DOI: 10.5852/ejt.2022.806.1699, http://zenodo.org/record/637396

The pharciceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea)

The ammonoids of the suborder Pharciceratina from the Red Ironstone Formation of the area around Dillenburg (eastern Rhenish Mountains) are revised, mainly based on historical collections stored in the Museum für Naturkunde, Berlin. The genus Evopharciceras gen. nov. and the following species are newly described: Maenioceras ornatum sp. nov., Pharciceras beyrichi sp. nov., Pharciceras kruegeri sp. nov., Pharciceras ferrum sp. nov., Evopharciceras formosum gen. et sp. nov., Extropharciceras metallicum sp. nov., Lunupharciceras kochi sp. nov., Stenopharciceras lotzi sp. nov., Pluripharciceras ahlburgi sp. nov. and Sandbergeroceras archiaci sp. nov. Neotypes are proposed for the species Extropharciceras becheri (von Buch, 1832) and Sandbergeroceras costatum (d’Archiac &amp; de Verneuil, 1842). The stratigraphic distribution of the genera is discussed; they are assigned to three assemblages: (1) Maenioceras terebratum Zone (early Givetian; two species), (2) Pseudoprobeloceras pernai Zone (latest Givetian; fifteen species) and (3) Sandbergeroceras costatum Zone (early Frasnian; three species).</p