The shark and ray fauna of the Upper Marine Molasse (Lower Miocene) of Rengetsweiler (Baden-Wurttemberg, SW Germany)

The sandpit near Rengetsweiler (Baden-Wurttemberg, SW Germany) is a famous locality for fossil shark and ray teeth from the Upper Marine Molasse (Lower Miocene). A total of 21 shark and ray genera were recovered from these sediments (Aetobatus, Alopias, Araloselachus, Carcharhinus, Carcharias, Carcharodon, Centrophorus, ?Dasyatis, Galeocerdo, Hemipristis, Isistius, Isurus, Mitsukurina, Notorynchus, Otodus (Megaselachus), Pachyscyllium, Physogaleus, Pseudocarcharias, Rhizoprionodon, Squatina, ?Triakis) as well as four specimens determinable as cf. Dasyatidae. The genera Araloselachus, Carcharoides, Otodus (Megaselachus), Pachyscyllium, and Physogaleus are extinct; all other taxa have living relatives. Based on extant representatives, the lifestyles of the ancient elasmobranchs range from a bottom-dwelling ambush predator (Squatina) to active swimming ones (Alopias, Carcharodon, Isurus, Otodus). Most of the taxa lived in the neritic realm. Members of Centrophorus, Isistius, Mitsukurina, and Pseudocarcharias are reconstructed as inhabitants of deeper water habitats. Based on Recent representatives and tooth shape, most of the taxa fed on invertebrates and/or fishes. Two taxa were dietary generalists (Galeocerdo, Notorynchus). Otodus fed on marine mammals. Carcharodon and adult Isurus also fed on marine mammals, in addition to fishes. Apart from the genera Centrophorus, Isistius, Mitsukurina, and Pseudocarcharias, the composition of the elasmobranch fauna as well as other fossil remnants and sedimentology indicate a fully marine, warm temperate and shallow water environment at the locality in the Lower Miocene. The normally deep water taxa probably came occasionally into the shallow sea of Rengetsweiler.