New marine reptile fossils from the Late Jurassic of Poland with implications for vertebrate faunas palaeobiogeography

Abstract

A new marine vertebrate assemblage from the Late Jurassic (late Kimmeridgian) at Krzyżanowice near Iłża in the NE margin of the Holy Cross Mountains in Poland is described. This new locality is rich in fossils of coastal and pelagic reptiles. The most frequent fossils are plesiochelyid turtle shell fragments and pliosaurid skull bones and teeth. The Krzyżanowice vertebrate assemblage is similar to the Late Jurassic Boreal/Sub-Boreal localities of the Kimmeridge Clay in Great Britain and Svalbard Archipelago in the Arctic, in the presence of pliosaurids and long-necked plesiosaurids. However, plesiochelyid turtles and crocodylomorphs are similar to those from the Mediterranean/Sub-Mediterranean sites of the northern border of the Tethys Ocean, as, for example, in the Swiss Jura Mountains and Southern Germany. This unique composition of the Krzyżanowice vertebrate fauna demonstrates that, during the Late Jurassic this new locality was located in the transitional palaeobiogeographic line referred to in this paper as the “Matyja-Wierzbowski Line”. The new palaeobiogeographical reconstructions of Late Jurassic of Europe are based on the composition of the Krzyżanowice locality and other sites with similar turtle-pliosaurid faunas which formed a long-term, stable ecological sympatry in marine ecosystems of the European Archipelago.