The Upper Ordovician (Sandbian) Letná Formation of Bohemia (Czech Republic) provides an important insight into the Early Palaeozoic diversification of marine ecosystems. In this formation, several levels can be interpreted as Konservat-Lagerstätten: they yielded abundant fossil remains, including exceptionally preserved, non-mineralized and poorly mineralized organisms. Non-trilobite arthropods (e.g. Duslia, Furca, Zonozoe) occur together with well-preserved trilobites, echinoderms, brachiopods and bivalves. Recently, a new locality at Chrustenice was discovered in the Letná Formation. It is characterized by mass occurrences of articulated echinoderms, which can be interpreted as storm-induced levels of accumulations (Konzentrat-Lagerstätten) of living or freshly killed individuals. The Chrustenice echinoderm assemblages are particularly diverse and dominated by solutans, associated with various asterozoans, blastozoans, crinoids, edrioasteroids, and stylophorans. The forthcoming description of these new assemblages will bring a wealth of new data on their systematics, functional morphology, taphonomy, palaeoecology, palaeobiogeography, and evolutionary implications. Preliminary investigations of the Chrustenice faunas show the occurrence of several ontogenetic stages in ophiuroids, as well as examples of ecological interaction, e.g. between solutans and edrioasteroids.