Brachiopods from the Early Carboniferous Erdbach limestones in Hesse (Germany, Kulm Basin)

The Early Carboniferous Erdbach limestones I, II, and III, deposited in crevasses (karst, tectonics) developed within Devonian carbonate reefs and submarine rises of volcanogenic origin in the eponymous area (Hesse, Germany), yielded a poorly diverse brachiopod fauna that was first studied by E. Holzapfel at the end of the nineteenth century. Re-investigation of the brachiopods based on recently collected material has led to the recognition of at least eleven species within the Tournaisian (Ivorian) Erdbach Limestone II (Scaliognathus anchoralis Zone), thus about twice as many as previously reported in the literature. The brachiopods, including both linguliforms and rhynchonelliforms, are very small (generally <= 10 mm in width) and thin-shelled; smooth spiriferides include homeomorphic species. Productidines, rhynchonellides and spire-bearers (athyridides, spiriferides) are specifically predominant among the Rhynchonelliformea. Former reports of Roemerithyris macrogaster (Roemer, 1852) from the Bromberg Formation (Goniatites crenistria Horizon; Asbian) at Elsoff in North Rhine-Westphalia are discussed. Four species from the historical type area of the Tournaisian Stage (Tournai, Belgium) are also discussed and/or illustrated, namely Orbiculoidea davreuxiana (De Koninck, 1843 in 1842-1844), O. portlockiana Demanet, 1934, O. tornacensis Demanet, 1934 (Linguliformea), and Acanthocrania psammophora (de Ryckholt, 1851) (Craniiformea), whose lectotype is selected.

Automated summary

The study focuses on the brachiopod fauna found in the Early Carboniferous Erdbach limestones in Hesse, Germany. The research reveals the presence of at least eleven species, which is double the number previously reported. The brachiopods are characterized by their small size, thin shells, and dominance of linguliforms and rhynchonelliforms.