Lingulate brachiopods from Lower Ordovician [Tremadoc] chalcedonites, Holy Cross Mountains, Poland

Lingulate brachiopods from chalcedonites of Tremadoc age are redescribed based on new material from the Holy Cross Mountains, Poland. The fauna includes 18 species, of which Elliptoglossa polonica and Siphonotretella popovi are new. The enigmatic Orbiculoidea? subovalis Biernat is redescribed as a species of the recently erected aberrant paterulids Diencobolus Holmer, Popov, Koneva, and Bassett. The fauna includes also Acrotreta dissimilis (Biernat), ?Ditreta dividua Biernat, Semitreta maior Biernat, Eurytreta minor Biernat, Mamatia retracta (Popov), Orbithele ceratopygarum (Brøgger), Siphonobolus uralensis (Lermontova), Alichovia analogica Biernat, Pomeraniotreta sp., Akmolina sp., Rowellella sp., Acanthambonia sp. A, Acanthambonia? sp. B, Leptembolon cf. lingulaeformis (Mickwitz), and the earliest known species of Eoconulus. Most of the recorded lingulate species are endemic, but a significant number are now known also from eastern Kazakhstan and the South Urals, as well as from the Tremadoc of Sweden and Norway.