Abstract

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 & 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).

Highlights

  • The study of late Givetian ammonoid assemblages is closely linked to the Roteisenstein (Red Ironstone) Formation in the Dillenburg and Oberscheld district at the eastern margin of the Rhenish Mountains

  • The revision of the Central European Late Givetian ammonoid species is entirely based on historical collections

  • From the second half of the 20th century, diverse late Givetian ammonoid assemblages have been discovered in the Anti-Atlas of Morocco (Petter 1959; Bensaïd 1974; Bockwinkel et al 2009, 2013a, 2015, 2017)

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Summary

Introduction

The study of late Givetian ammonoid assemblages is closely linked to the Roteisenstein (Red Ironstone) Formation in the Dillenburg and Oberscheld district at the eastern margin of the Rhenish Mountains. Almost all Late Givetian ammonoid species newly described before 1960 originate from the Dillenburg area, and most of these specimens were collected in the course of intensive underground ironstone mining. From the second half of the 20th century, diverse late Givetian ammonoid assemblages have been discovered in the Anti-Atlas of Morocco (Petter 1959; Bensaïd 1974; Bockwinkel et al 2009, 2013a, 2015, 2017). This material is much better preserved than the Rhenish material and allows a substantially better understanding of the morphological spectrum. The Moroccan material consists of both calcareous specimens and limonitic internal moulds

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