Review of collections in Prague and at Harvard University, supplemented by additional field observations, has allowed taxonomic updating and revision of Barrandian trinucleid trilobites. Genera identified are Bergamia, Declivolithus, Nankinolithus, Tretaspis, Marrolithus, Deanaspis, and Onnia. One earlier described species is assigned to the new genus Marekolithus.

Although partly isolated from the rest of north Gondwana during the Ordovician, the Prague Basin shares faunas with Sardinia and Morocco, as all show the transition from Deanaspis to Onnia. Spain, Britain, and the Baltic also share some species with Bohemia, particularly in the high Caradoc and Ashgill (Bohdalec and Králův Dvůr Formations).