Geosaurus is an extinct genus of marine crocodyliform within the family Metriorhynchidae, that lived during the Late Jurassic and the Early Cretaceous.

[5] G. suevicus had a distinctively long, narrow snout filled with small, pointed teeth very different from skulls belonging to the type species.

[15] G. lapparenti G. grandis G. giganteus In 2009, Young and de Andrade published a re-description of Geosaurus, examining its relationships and the validity of species lumped into the genus.

Specifically, they found that several species formerly classified as Geosaurus, including G. suevicus, G. saltillense,[16] G. vignaudi,[17] and G. araucanensis[18] were actually examples of the related Cricosaurus.

[14] An unnamed specimen classified as Geosaurus was found in the Oxfordian Jagua Formation of Cuba,[20] though further study has shown this species to be more closely related to Cricosaurus as well.

[21] Several species of metriorhynchids are known from the Mörnsheim Formation (Solnhofen limestone, early Tithonian) of Bavaria, Germany: Geosaurus giganteus, Dakosaurus maximus, Cricosaurus suevicus and Rhacheosaurus gracilis.

The long-snouted C. suevicus and R. gracilis would have fed mostly on fish, although the more lightly built Rhacheosaurus may have specialised towards feeding on small prey.