This is a jaw of the crocodile Steneosaurus. The fossil comes from the layers of the Lower Jurassic (Lias epsilon), it was found in the world-famous classical locality Holzmaden in Germany.
Fossils of Steneosaurus are rarely found compared to remnants of ichtyosaurs.
This jaw still contains seven teeth.
The plate is glued, it measures about 13 x 9.5 cm.