Late Permian ichthyofauna from the North-Sudetic Basin, SW Poland

The late Permian time was a transformative period before the most severe mass extinction known. Even though fishes constitute a key component of marine ecosystems since the Silurian, their biogeographic patterns during the late Permian are currently insufficiently known. The new ichthyofaunal material described here comes from the southeastern part of the Zechstein Basin, from the calcareous storm sediments alternating with marls, which were deposited in less energetic conditions. Chondrichthyans and osteichthyans are reported here for the first time from the Nowy Kosciol quarry in the SW Poland. The assemblage consists of various euselachian dermal denticles, actinopterygian scales and teeth, and isolated hybodontoid tooth putatively assigned as extremely rare ?Gansuselache sp. from the Permian. The diverse actino-pterygian tooth shapes show significant ecological differentiation of fishes exploring sclerophagous, durophagous, and herbivory modes of feeding in the given part of the Zechstein Basin suggesting the presence of complex ecosystems even in hyper-saline conditions of an epicontinental sea.

Automated summary

This study presents new ichthyofaunal material from the Zechstein Basin, revealing the presence of chondrichthyans and osteichthyans for the first time in the Nowy Kosciol quarry in SW Poland. The diverse actino-pterygian tooth shapes suggest significant ecological differentiation of fishes exploring different modes of feeding in the late Permian, even in hyper-saline conditions of an epicontinental sea.