The oldest hyolith fauna of the Jince Formation (mid-Cambrian, Barrandian area, Czech Republic)

摘要

The mid-Cambrian Jince Formation of the Barrandian area is globally renowned as a classical repository of exceptionally diverse and well preserved hyoliths. However, our knowledge about hyoliths of the mid-Cambrian Jince Formation of the Pribram-Jince Basin is quite incomplete and the locally abundant and well preserved hyolith specimens are not adequately studied. The hyolith association studied herein consists of three hyolithids and three orthothecids from the lower stratigraphic levels of the Jince Formation and constitutes a considerable increase of our knowledge. The studied material is preserved as internal and external moulds in calcareous nodules, fine greywackes and shales. Except for one taxon, Maxilites sp., the other five hyolith species, Oboedalites oboediens MAREK, 1981, Slehoferites slehoferi MAREK, 2011, Circotheca sp., Gracilitheca triangularis VALENT et al., 2013, and Probactrotheca briketa MAREK, 2012 are new for the Pribram-Jince Basin; previously these species have been known exclusively from the Buchava Formation of the Skryje-Tyrovice Basin of the Barrandian area.