Radek Vodrážka

Entobia exogyrarum (Frič, 1883) from the Upper Cretaceous of the Bohemian Cretaceous Basin

The validity of the little-known ichnospecies Entobia exogyrarum (Frič) is verified. Shells of an oyster, Rhynchostreon suborbiculatum (Lam.), represent the substrate for the sponge borings. The borings occur in many Upper Cenomanian to Middle Turonian localities of the Bohemian Cretaceous Basin. This study revealed that the sponges attacked shells of living oysters. Entobia exogyrarum (Frič) also represents one of the shallowest occurrences of Entobia borings in the Upper Cretaceous rocks.

Foraminifera from the Upper Cretaceous of northern James Ross Island (Antarctica): a preliminary report

The Cretaceous biostratigraphy of the James Ross Island region is generally based on palynomorphs and macrofossils (bivalves, ammonites). During geological mapping of the northern James Ross Island a number of samples from Upper Cretaceous lithologies were gathered to test the presence of foraminifers as a possible tool for stratigraphic evaluation of Upper Cretaceous strata. Limited number of samples did not provide foraminiferal content large enough to give relevant information for biostratigraphic conclusions. Samples from older sediments of Whisky Bay and Kotick Point formations (Albian – Turonian) were either not fossiliferous or contained scarce specimens of agglutinated foraminifers. Foraminiferal assemblages from younger sediments of Hidden Lake and Santa Marta formations (Coniacian – Campanian) contained species with both agglutinated and calcareous types of tests. Many of studied marine sediments were barren of foraminifers, probably due to late diagenetic secondary decalcification. Taxonomy of low-diversified assemblages was carried out and a biostratigraphical and palaeobiogeographical significance discussed.