New insights on Tournaisian–Visean (Carboniferous, Mississippian) athyridide, orthotetide, rhynchonellide, and strophomenide brachiopods from southern Belgium

Twelve selected Carboniferous species belonging to seven genera of the orders Athyridida, Orthotetida, Rhynchonellida, and Strophomenida (Brachiopoda) from southern Belgium are revised and/or discussed, and sometimes photographed for the first time since their first description dating back to the 19 th century. The investigated material originates from the historical type areas of the Tournaisian and Visean stages (Tournai and Vis, respectively) and from the Waulsortian carbonate buildups developed in the Namur-Dinant Basin. Two species are new (Leptagonia franca sp. nov., Serratocrista scaldisensis sp. nov.), and a new name is proposed (Nucleospira hannoniae nom. nov.) to solve the primary homonymy between Athyris globulina de Koninck and A. globulina Waagen. Taxonomic discussion involves selection of the holotype of Retzia intermedia de Koninck (definitely not an athyridide) and of lectotypes for several species of athyridides (Athyris globulina de Koninck, A. vittata de Koninck, and Retzia davidsoni de Koninck), and strophomenides (Orthis cylindrica M'Coy, Schellwienella radialiformis Demanet, and S. ornata Demanet). The palaeoecology of the investigated species and their biotic interactions with other organisms (e.g., drill holes, epizoans) are described. The analysis of the published data on the athyridides, orthotetides, and strophomenides occurring in southern Belgium during the Devonian-Mississippian reveals that our knowledge of these suspension-feeders in this part of the southern margin of Laurussia is currently insufficient to assess the aftermath of the different biological crises that took place during this time span, notably the Hangenberg Crisis at the end of the Famennian.