<abstract xmlns="http://www.w3.org/1999/xhtml"><p>Deep-neritic sediments of the Eferding Formation (Egerian, Upper Oligocene) of Upper Austria from the Kamig kaolinite quarry revealed minute teeth of the putatively planktivorous shark genus <italic>Nanocetorhinus</italic>. This is the oldest unambiguous record of this rarely documented genus, which was known so far only from Miocene deposits of Europe, North America and Japan. Based on previous studies, which showed a positive correlation between sediments of nutrient rich waters and plankton blooms with a majority of ichthyoliths of <italic>Keasius</italic> and <italic>Nanocetorhinus</italic>, we argue for a filter-feeding and migratory lifestyle of the latter. Thus, it is supposed that <italic>Nanocetorhinus</italic> migrated seasonally for foraging, in a similar way to the extant basking shark <italic>Cetorhinus maximus</italic>. This mode of life and the wide paleogeographic distribution of the open marine genus <italic>Nanocetorhinus</italic> requires a deep and fully marine connection between the Paratethys and the Proto-Mediterranean Sea during late Oligocene times, which might have been established via the Slovenian Corridor.</p></abstract>

Deep-neritic sediments of the Eferding Formation (Egerian, Upper Oligocene) of Upper Austria from the Kamig kaolinite quarry revealed minute teeth of the putatively planktivorous shark genus Nanocetorhinus. This is the oldest unambiguous record of this rarely documented genus, which was known so far only from Miocene deposits of Europe, North America and Japan. Based on previous studies, which showed a positive correlation between sediments of nutrient rich waters and plankton blooms with a majority of ichthyoliths of Keasius and Nanocetorhinus, we argue for a filter-feeding and migratory lifestyle of the latter. Thus, it is supposed that Nanocetorhinus migrated seasonally for foraging, in a similar way to the extant basking shark Cetorhinus maximus. This mode of life and the wide paleogeographic distribution of the open marine genus Nanocetorhinus requires a deep and fully marine connection between the Paratethys and the Proto-Mediterranean Sea during late Oligocene times, which might have been established via the Slovenian Corridor.

A new species of the enigmatic shark genus <italic>Nanocetorhinus</italic> (Chondrichthyes) from the Oligocene of Austria with palaeoceanographic implications

juergen.pollerspoeck@shark-references.com

Geological-Palaeontological Department, Natural History Museum

Austrian Journal of Earth Sciences

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

A new species of the enigmatic shark genus  (Chondrichthyes) from the Oligocene of Austria with palaeoceanographic implications

Deep-neritic sediments of the Eferding Formation (Egerian, Upper Oligocene) of Upper Austria from the Kamig kaolinite quarry revealed minute teeth of the...

A new species of the enigmatic shark genus Nanocetorhinus (Chondrichthyes) from the Oligocene of Austria with palaeoceanographic implications

Published Online: Nov 28, 2020

Page range: 229 - 236

Received: Aug 11, 2020

Accepted: Nov 06, 2020

DOI: https://doi.org/10.17738/ajes.2020.0014

Keywords
Paratethys, Egerian, Elasmobranchii, planktivorous, dermal denticle

© 2020 Iris Feichtinger et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

A new species of the enigmatic shark genus Nanocetorhinus (Chondrichthyes) from the Oligocene of Austria with palaeoceanographic implications

Published Online: Nov 28, 2020

Page range: 229 - 236

Received: Aug 11, 2020

Accepted: Nov 06, 2020

DOI: https://doi.org/10.17738/ajes.2020.0014

KeywordsParatethys, Egerian, Elasmobranchii, planktivorous, dermal denticle

© 2020 Iris Feichtinger et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Keywords
Paratethys, Egerian, Elasmobranchii, planktivorous, dermal denticle