Evidence of theropod dinosaurs from a Lower Cretaceous karst filling in the northern Sauerland (Rhenish Massif, Germany)

Theropod dinosaur teeth from a Lower Cretaceous karst filling in Devonian reef limestone (Massenkalk) located near the village of Balve on the northern margin of the Rhenish Massif, Germany, are described. Palynological evidence indicates that the karst filling took place during the Late Barremian to (Early) Aptian time interval. Palaeontological excavations carried out during several years at the Balve locality yielded remains of various animal groups, including sharks, amphibians, turtles, crocodiles, pterosaurs, herbivore dinosaurs, and, rarely, mammals. Of particular interest is an assemblage of different theropod dinosaur teeth, which has been characterized with the help of dental comparative morphometry. Based on these analyses, the teeth material from the Balve excavation can be assigned to five morphological groupings including dromaeosaurid and tyrannosauroid theropods. Morphological comparison of the theropod dinosaur teeth record with finds from other fossil localities in western and northwestern Europe of similar age shows clear similarities, but also some distinct differences.