BOLIVINOIDES (BENTHIC FORAMINIFERA) FROM THE UPPER CRETACEOUS OF POLAND AND WESTERN UKRAINE: TAXONOMY, EVOLUTIONARY CHANGES AND STRATIGRAPHIC SIGNIFICANCE

摘要

The taxonomy of Late Cretaceous genus Bolivinoides is revised on the basis of rich, newly collected material from central and eastern Poland and western Ukraine. Twelve species are described of which one is new: Bolivinides intermedius nov. sp. This species differs from the other bolivinoidid taxa in possessing two parallel medial rows of tubercles. The stratigraphic ranges of most of the taxa are compared with the macrofossil standard zonation, which allowed a correlation with the occurrence of bolivinoidids of distinct regions of Europe and other continents. The evolutionary trends of Bolivinoides are also discussed and two distinct lineages, Bolivinoides strigillatus and Bolivinoides laevigatus, are distinguished.