Tremadocian trilobites of the Prague Basin, Czech Republic
A revision of the trilobites of the Třenice and Mílina Formations (Upper Tremadocian) confirms the presence of 29 species. Celdometopus gen. n. is established, and six new species, Agerina clymene, Hemibarrandia klouceki, Holoubkocheilus asopus, Parabathycheilus krafti, Platypeltis perseis, and Pricyclopyge oceanitis are described. All formerly described species of the genera Geragnostus, Ottenbyaspis, Hemibarrandia, Holoubkovia, Anacheirurus, Parapilekia, Parabathycheilus, Holoubkocheilus, Proteuloma, Harpides, Holubaspis, Dikelokephalina, Ceratopyge, Niobina, Apatokephalus, Celdometopus, and Eulomina, are re-described or further commented on. Old and new data about their morphology, distribution, and affinity are summarized. The fauna contains numerous cosmopolitan taxa, but most of the species show Gondwanan affinity, especially among calymenaceans and by the presence of an early cyclopygid. Compared with other regions, the total absence of olenid trilobites is characteristic. A high taxonomic diversity with dominant cheirurids and illaenids makes this one of the richest late Tremadocian trilobite faunas ever described.