Helcionelloids, stenothecoids and hyoliths from the Tannenknock Formation (traditional lower middle Stage 4/Wuliuan boundary interval) of the Franconian Forest, Germany

The early middle Cambrian Tannenknock Formation of the Franconian Forest, traditionally subdivided into the Galgenberg and Wildenstein strata, yields a relatively diverse fauna. This fauna includes a number of molluscs, which portrays a fairly diverse assemblage that can be regarded as paradigmatic for the lower-middle Cambrian boundary interval in West Gondwana, with the helcionelloid genera Helcionella, Bemella, Igorella, Latouchella, Leptostega, Yochelcionella, the pelagiellid Pelagiella, a stenothecoid, and the Hyolithida Hyolithes?, Hexitheca?, Jincelites, Maxilites?, Aladraco, Cambrachelous, the Orthothecida Brevitheca?, Nephrotheca?, and a number of helcionelloid and hyolith forms dealt with under open nomenclature. New species include the helcionelloids Helcionella lemdadensis sp. nov. and Leptostega frankenwaldensis sp. nov. and the hyoliths Grantitheca? klani sp. nov. and Cambrachelous diploprosopus gen. et sp. nov. The stenothecoid discovered in the Wildenstein Member of the formation is the first report of the group from West Gondwana.