New insight into the distribution and palaeobiology of the pycnodont fish Gyrodus
The pycnodont fish Gyrodus is reported for the first time from the Lower Cretaceous of Germany based on two lower jaw elements from the Hauterivian and Barremian. The stratigraphic and geographic distribution of Gyrodus is summarized. Gyrodus ranges from the Middle Jurassic to the Early Cretaceous making it one of the longest living pycnodonts. Unambiguous Late Cretaceous records of Gyrodus are still missing. Gyrodus displays its widest distribution and greatest taxonomic diversity in the Late Jurassic. The distribution of Gyrodus implies not only near-coastal mode of life but also a pelagic lifestyle conversely to most other pycnodonts. External body features and function of the unpaired fins support this interpretation.
Key words: Neopterygii, Pycnodontiformes, Gyrodus, Cretaceous, palaeobiogeography, Germany.
Jürgen Kriwet [j.kriwet@lrz.uni−muenchen.de], Ludwig−Maximillians−University, Faculty of Geosciences, Department of Earth and Environmental Sciences, Section of Palaeontology, Richard−Wagner−Str. 10, 80333 Munich, Germany; Lars Schmitz [lSchmitz@geology.ucdavis.edu], Department ofGeology, University of California, Davis, CA 95616, USA.
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