News archive

Modern gobies (Gobioidei, Teleostei) are classified to eight families, although exclusively fossil representatives of this suborder have been reported too. One of these extinct forms is the small fish of the genus Pirskenius, which was originally placed into a specific family Pirskeniidae, or to the family Eleotridae (sleeper gobies). Its specimens are known only from Oligocene deposits of northern Bohemia. New research published in journal Plos One, also contributed by T. Přikryl of the Institute of Geology, focused on this Oligocene genus and compared it with other gobiids using modern methods including micro-CT scanning. Detailed analyses validated the separate family Pirskeniidae and resulted in more precise diagnoses for the genus Pirskenius and the family Pirskeniidae. The results of phylogenetic analysis suggest that the family Pirskeniidae represents a sister group of the clad Thalasseleotridae + Gobiidae + Oxudercidae. In a broader context, the intrusion of gobiids into the Oligocene freshwater environment can be viewed as an impus generating new forms which became extinct shortly after their spread.

On the 20th August this year, we said our last good-bye to Dr. Vojen Ložek – an outstanding Czech naturalist of worldwide reputation, and an emeritus employee of the Institute of Geology. He was a foremost expert in European nature, focusing his effort on the study of the Quaternary and especially molluscan biology. Vojen Ložek was not only an excellent scientist receiving many awards (e.g., the golden Albrecht Penck medal in honour of his advances in Quaternary studies in global scale and the Award of the Minister of the Environment CR) but also an endowed teacher and a highly vital man: he was loving his fieldwork and was always ready to deliver brilliant lectures to the professional audience as well as to the public. His passing is a great loss to many of his students, colleagues and followers. Nevertheless, his work is staying with us. His memory be honoured.

A newly published paper in the Geomorphology journal precisely described the origin of the recently recognized sandstone weathering forms – arcade cavities, but also the closely related hourglass-shaped pillars. It benefits from advanced numerical modeling. In general, this study relates to the application of a completely new approach, which yielded, within a short time, quite surprising results for the understanding of weathering of granular rocks. The research is carried out in close cooperation with the Faculty of Science of Charles University in Prague and the Skolkovo Institute of Science and Technology in Moscow. This particular publication was substantially contributed by Michal Filippi of the Institute of Geology of the CAS.

The study of several thousand Ordovician (i.e., early Palaeozoic) fossils, mostly trilobites, bivalves, gastropods and echinoderms, demonstrated that most carcasses have become a subject of systematic and sophisticated feeding since the Mid Ordovician. Feeding traces have been preserved as thin tunnels insubstrate inside shells of dead organisms. For a certain period, the substrate had been enriched by microbial consortia; firm fibrous tissues could function as the source of organic matter. Feeding patterns tend to recur for each fossil group; thereby, the positions and shapes of certain non-preserved tissues can be estimated. The above mentioned complex feeding strategies appeared around the GOBE (i.e., Great Ordovician Biodiversification Event) which occurred mainly from 465 to 460 Ma. Paper.