Offshore marine actinopterygian assemblages from the Maastrichtian-Paleogene of the Pindos Unit in Eurytania, Greece

Thodoris Argyriou; Donald Davesne

doi:10.7717/peerj.10676

Offshore marine actinopterygian assemblages from the Maastrichtian-Paleogene of the Pindos Unit in Eurytania, Greece

PeerJ. 2021 Jan 20:9:e10676. doi: 10.7717/peerj.10676. eCollection 2021.

Authors

Thodoris Argyriou¹, Donald Davesne^{2

3}

Affiliations

¹ UMR 7207 (MNHN-Sorbonne Université-CNRS) Centre de Recherche en Paléontologie, Museum National d'Histoire naturelle, Paris, France.
² Department of Earth Sciences, University of Oxford, Oxford, UK.
³ UMR 7205 (MNHN-Sorbonne Université-CNRS-EPHE), Institut de Systématique, Évolution, Biodiversité, Museum National d'Histoire naturelle, Paris, France.

Abstract

The fossil record of marine ray-finned fishes (Actinopterygii) from the time interval surrounding the Cretaceous-Paleogene (K-Pg) extinction is scarce at a global scale, hampering our understanding of the impact, patterns and processes of extinction and recovery in the marine realm, and its role in the evolution of modern marine ichthyofaunas. Recent fieldwork in the K-Pg interval of the Pindos Unit in Eurytania, continental Greece, shed new light on forgotten fossil assemblages and allowed for the collection of a diverse, but fragmentary sample of actinopterygians from both late Maastrichtian and Paleocene rocks. Late Maastrichtian assemblages are dominated by Aulopiformes (†Ichthyotringidae, †Enchodontidae), while †Dercetidae (also Aulopiformes), elopomorphs and additional, unidentified teleosts form minor components. Paleocene fossils include a clupeid, a stomiiform and some unidentified teleost remains. This study expands the poor record of body fossils from this critical time interval, especially for smaller sized taxa, while providing a rare, paleogeographically constrained, qualitative glimpse of open-water Tethyan ecosystems from both before and after the extinction event. Faunal similarities between the Maastrichtian of Eurytania and older Late Cretaceous faunas reveal a higher taxonomic continuum in offshore actinopterygian faunas and ecosystems spanning the entire Late Cretaceous of the Tethys. At the same time, the scarcity of Paleocene findings offers tentative clues for a depauperate state of Tethyan ichthyofaunas in the aftermath of the K-Pg Extinction.

Keywords: Actinopterygii; Fossil fishes; Greece; K–Pg Extinction; Maastrichtian; Paleocene; Pindos Unit; Tethys.

Grants and funding

This work was supported by the Swiss National Science Foundation early postdoc mobility grant P2ZHP3_184216 to Thodoris Argyriou. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.