Otoliths of fish from the Early Cretaceous of Poland

About 140 million years ago, Poland was a sea connecting the Tethys Ocean with the Boreal Sea. The fish that inhabited this sea left no skeletal remains, but have been identified based on otoliths, found in Wąwał, central Poland. Those “earstones” are responsible (among others) for sense of balance. This study shows that Early Cretaceous seas covering Poland were populated by the ancestors of silverfish, Japanese gisu fish, and cousins of slanderers, albulas and marine relatives of arapaima. Interestingly, some otolith species were previously known from younger marine sediments.