Trilobite biostratigraphy of the Králův Dvůr Formation (Upper Katian, Prague Basin, Czech Republic): Global faunal changes or facies-related distribution?
Abstract
Eight trilobite associations and sub-associations have been distinguished in the Králův Dvůr Formation. Their spatial distribution reflects lithology; their succession was dictated by global climatic changes and palaeogeography. Locally developed "Podolí Ore Horizon" Assoc. contains survivals from the Bohdalec Formation and the late Katian taxa. The Amphitryon-Kloucekia Assoc. is newly established for the lower two thirds of the formation. Within this association can be distinguished four sub-association
1) the newly established Onnia ultima sub-Assoc. with dominance of Onnia and Flexicalymene
2) the deeper-water Nankinolithus granulatus sub-Assoc.,
3) brachiopod-dominated Dedzetina-Tretaspis sub-Assoc. and
4) the Tretaspis anderssonni sub-Assoc. Impure limestone below top of the formation contains a temperate-water Marekolithus kosoviensis Assoc. The Mucronaspis Assoc. is characteristic for the uppermost portion of formation. It persisted till the onset of the glaciation at the base of Hirnantian.