Cambrian biostratigraphy in the Pribram-Jince Basin (Barrandian area, Czech Republic)

Previously published biostratigraphical subdivisions of the middle Cambrian succession of the Pribram-Jince Basin in the Barrandian area are summarized and a modified subdivision of twelve biozones proposed. Nine of the biozones are delimited by the first appearance of the eponymous species; five of these are interval zones and four are taxon-range zones. The youngest stratigraphical levels of the fossiliferous sequence in the Litavka River Valley, which lack any characteristic taxa, are assigned to one assemblage zone that is subdivided into two levels defined by the presence of two trilobites and two lingulate brachiopods. The Kodymirus vagans, Hypagnostus parvifrons and Dawsonia bohemica zones, and the Barren interzone between Paradoxides (Eccaparadoxides) pusillus-Paradoxides (Paradoxides) paradoxissimus gracilis, are newly established; the other zones are redefined or the earlier definitions retained.