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

Abstract

The ammonoids of the suborder Tornoceratina from the Middle to Late Devonian 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 species Tornoceras typus (Sandberger & Sandberger, 1851), Tornoceras frechi Wedekind, 1918 and Epitornoceras mithracoides (Frech, 1888) are re-described based on the original material from the Red Ironstone. The new genus Lentitornoceras gen. nov. is proposed for the new species L. materni gen. et sp. nov.; the new genus Paucitornoceras gen. nov. is proposed with the type species Goniatites paucistriatus. Epitornoceras transmediterraneum sp. nov. is described from the Anti-Atlas of Morocco and compared with E. mithracoides.

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

“…In the meantime, two monographs on the ammonoids of the Red Ironstone have been published; these dealt with the suborders Pharciceratina (Korn & Bockwinkel 2021) and Tornoceratina (Korn & Bockwinkel 2022). In a third step of the revision, we here present the re-description of the ammonoids of the suborder Gephuroceratina, of which eight species are described.…”

“…The stratigraphic occurrence of the species of the suborder Pharciceratina has already been discussed by Korn & Bockwinkel (2022). There, it was concluded that these forms originate from three intervals, in ascending order: (1) Maenioceras terebratum Zone, (2) Pseudoprobeloceras pernai Zone and (3) Sandbergeroceras costatum Zone.…”

The ammonoids from the Gattendorfia Limestone of Oberrödinghausen (Early Carboniferous; Rhenish Mountains, Germany)

“…The genus Kornia was introduced by for very small specimens which are characterised by their spindle-shaped conch and conspicuous umbilical shape, thus differing strongly from all other known early Tournaisian ammonoids. Juvenile ammonoids with such a shape, however, occur repeatedly in the fossil record, as shown for the Late Viséan genera Goniatites de Haan, 1825 (Klug et al 2016;Korn 2017) and Hibernicoceras Moore & Hodson, 1958(Schmidt 1925Korn 1988a).…”

“…In the Treatise revision, Kullmann (2009) expressed a view of the family Gattendorfiidae that is clearly different from previously published concepts (Bartzsch & Weyer 1987, 1988aKorn 1994;. His scheme differs, on the one hand, in that the gattendorfiid and pseudarietitid clades are not considered as sister groups and, on the other hand, in that genera such as Acutimitoceras and Stockumites are also placed in the family Gattendorfiidae.…”

“…Species of the Gattendorfiinae are nearly worldwide distributed and were described from the Rhenish Mountains (Schmidt 1924(Schmidt , 1925Vöhringer 1960;Korn 1994Becker 1997;Korn & Vöhringer 2004;Becker et al 2021), Thuringian Mountains (Schindewolf 1924(Schindewolf , 1926a(Schindewolf , 1952Pfeiffer 1954;Weyer 1976Weyer , 1977Bartzsch & Weyer 1982, 1987, 1988a, 1988b, Upper Franconia (Münster 1839;Schindewolf 1923), Silesia (Weyer 1965;Dzik 1997), the Carnic Alps (Korn 1992b;Schönlaub et al 1992), the Montagne Noire . They are also known from Anti-Atlas , western Algeria (Conrad 1984;), the South Urals (Popov 1975;Popov & Kusina 1997), Karaganda (Librovitch 1940) and Mongolia (Kusina & Lazarev 1994).…”