Fossil treasure detected at the Natural History Museum Vienna: new marine crocodiles from the early Cretaceous
Historic collections can always appear with surprises! Scientists of the Natural History Museum Vienna (NHM Vienna), the Natural History Museum Bielefeld, the Academy of Scienes Poland, the Institute for Geological Engineering in Czech Republic and the School of GeoSciences in England elicited new insights in fossil teeth of early Cretaceous marine crocodiles.
In 1912 two 2 cm large tooth crowns arrived with other marine fossils at the Natural History Museum Vienna, subsequently included in the collections without any detailed taxonomic determination. The tooth crowns derive from quarries of the city Štramberk in the Czech Republic. More than hundred years later Sven Sachs from the Natural History Museum Bielefeld detected the true nature of the 138 millionen year old fossils during his scientific studies at the NHM Vienna. The teeth derive from members of the extinct marine crocodile family Metriorhynchidae. Their name is based on the moderate elongated snout. Together with the dinosaurs, the pterosaurs, crocodiles and the birds they belong to the group of archosaurs. The Metriorhynchidae were an important component in shallow marine ecosystems in the middle Jurassic up to the early Cretaceous. They populated North- to South-Amerika and the European archipelago and were amongst the archosaur group which was most optimally adapted to the life in marine waters. The animals were up to 7 meter in length and appear with extremities transformed to flippers.
Recently an international team with Alexander Lukeneder, Palaeontologist at the Natural History Museum Vienna, together with Daniel Madzia, Sven Sachs, Mark T. Young and Petr Skupien investigated these historical fossils. The analysis of the dental enemal show that the tooth crowns belong to two different animals: Plesiosuchus and Torvoneustes. Both genera had different nutritian strategies. Plesiosuchus hunted on other marine reptiles as pliosaurs, whilst Torvoneustes was specialised to prey on fish and ammonites. The recently described specimens from the Natural History Museum Vienna depict
some of the youngest metriorhynchid crocodile specimens worldwide. During the Cretaceous period, long before the extinction of the dinosaurs, these marine reptiles disappeared.
The study shows the importance of isolated teeth fossils for the reconstruction of ancient environments and once more underlines the enormous potential of historic natural scientific collections for modern science. Even decades after the acquisition modern methods or the visit of specialists can elicite new secrets from our collections.
Priv.-Doz. Dr. Alexander Lukeneder
Curator for the Mesozoic collection
Tel.: +43 (1) 52177- 251
Madzia, D., Sachs, S., Young, M.T., Lukeneder, A., Skupien, P. 2021. Evidence of two lineages of metriorhynchid crocodylomorphs in the Lower Cretaceous of the Czech Republic. Acta Paleontologica Polonica.