Fossil fishes from northern Bohemia targetted by scientists again

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.