Somewhat rarer than ichthyosaurs, crocodile-like reptiles occur in the Posidonia Shale. Most prominent is the extinct genus Steneosaurus, another example is Pelagosaurus.
The name Steneosaurus actually means lizard. They lived during the Jurassic and Lower Cretaceous, with fossils found mainly in Europe, such as in Germany or France, and in Morocco. Size is species-specific, though Steneosaurus was often between 2.5 m and 3.5 m long. The largest of this genus, however, grew up to 5 m long. Steneosaurus lived mainly in shallow coastal waters where it hunted fish and other small marine organisms. Accordingly, the teeth were also specialized in catching fish. These are conical and slightly curved. Depending on the species, it had between 20 and 60 teeth. In addition, 4 to 5 teeth were found in the intermaxillary bone (premaxillary) located in front of the upper jaw. Further characteristics are that Steneosaurus had upward directed eye sockets in contrast to its smaller relative Pelagosaurus, whose eye sockets (orbita) were located at the side of the skull, and that the antorbital window was relatively small.
Steneosaurus teeth are more comon in Holzmaden compared to other reptiles. Especially in the "Schlacke" (Lias epsilon II 12) they are frequently encountered. This comparatively high frequency of finds suggests that Steneosaurus had a strong change of teeth. The most common species in the Posidonia Shale is Steneosaurus bollensis, which has a rather long snout. Corresponding to the size of Steneosaurus bollensis, the teeth are not very big either. Mostly they reach a size of about 1 - 1,5 cm.