Deep-marine elasmobranchs from the Badenian (Langhian, Middle Miocene) of the Central Paratethys of Austria

This study reports on a rare assemblage of deep-marine elasmobranchs from the middle Badenian (Langhian) of Austria, which has been recovered by extensive bulk sampling of sediment deposited in the Krems embayment. The applied multidisciplinary approach enabled an age assignment, placing the assemblage around the mid Badenian flooding event (14.59 ± 0.2 Ma). Palaeoenvironmental reconstruction, based on a well-preserved foraminifera assemblage and fish otoliths, indicates predominantly oxic to suboxic with partially dysoxic conditions of a rather deep-marine (>100 m) setting, which align with the recovered elasmobranch taxa. Despite analyzing 180 kilograms of sediment, only five elasmobranch teeth were recovered. The low number of teeth and the extraordinarily well-preserved foraminifera argue for an autochthonous deposition and point to high sedimentation rates associated with the flooding event. The teeth represent five different elasmobranch orders (Squaliformes, Squatiniformes, Carcharhiniformes, Torpediniformes, and Myliobatiformes) with a wide range of feeding behaviors, providing new insights into the ecological structure of this deep-marine environment. Despite common genera known from other marine settings of the Paratethyan realm (e.g., Squatina, Scyliorhinus, and Centrophorus), this study documents the first distinct records of Torpedo and Mobula from Austria, expanding the known palaeogeographic distribution of these taxa.