In Depth
Pontosaurus was a semi aquatic lizard with an extremely elongated body that features a laterally compressed tail around twice the length of the body. Pontosaurus is so snake-like that it is considered to represent the form of reptiles that were ancestral to snakes, though was probably not the ancestor due to its late appearance in the fossil record. Additionally semi aquatic lizards similar to Pontosaurus are thought to have given rise to the mosasaurs of the late Cretaceous.
Pontosaurus was originally named as Hydrosaurus, but this had already been used to name a genus of agamid lizard.
Further Reading
– A new species of Pontosaurus (Squamata, Pythonomorpha) from the Upper Cretaceous of Lebanon and a phylogenetic analysis of Pythonomorpha. – Memorie della Societa Italiana di Scienze Naturali e del Museo Civico di Storia Naturale di Milano 34:1-42. – M. W. Caldwell – 2006.