New data on Paleocene-Eocene fauna (gastropods, ostracods, fishes) and palynoflora of the Boltysh impact structure (Ukraine) with biostratigraphical and paleoecological inferences

摘要

The Boltysh impact structure (Ukraine) has preserved Paleocene to Eocene sediments that provide pollen, dinocysts, remains of plants, gastropods, ostracods, fishes and amphibians, which have all been previously described from that locality. Although fossil records from the locality are known from the second half of the 20th century, it gets in the focus again, because the crater structure was newly dated at 65.59 +/- 0.64 Ma. Here we describe some new material comprising palynomorphs (in total 10 plant species, fungal spores), as well as two species of gastropods, 17 species of ostracods (with three species introduced as new to science) and five taxa of actinopterygian fishes. Although some of the original material was not available for direct study, important data from literature (i.e. diagnoses, type specimens and significant comments) are presented. The ostracod assemblages suggest that the sediments were deposited in lake environments under marine influence causing changes in water salinity. The fish fauna is comparable to Paleogene localities of Central and Western Europe, especially the Menat locality (late Paleocene, Thanetian), and the Eocene (Lutetian) localities of Geiseltal and Montmartre. In summary, the publication presents overview of the selected fossil groups with new interpretations and description of several taxa.