[9] The first skull of Eurhinosaurus longirostris was found by Owen and Jaeger in Switzerland in 1856, which showed clearly shortened mandibles.

[4] The genus Eurhinosaurus was erected in 1909 in a paper describing the Miocene cetacean Eurhinodelphis cocheteuxi.

Abel noted that it was not certain whether the cetacean's mandible extended to the tip of the snout or whether it was abbreviated, which was like the case in Ichthyosaurus longirostris in 1851.

[9] He considered that the weak, attenuated mandible and some other distinguishing features of Ichthyosaurus longirostris and decided to erect a separate genus and names as Eurhinosaurus.

[3] Their huge orbits were combined with an extremely short cheek region and reduced upper temporal openings.

Eurhinosaurus had the quadratojugal with long posteromedial processus quadratus and pierced by foramen of unknown function.

Some small interpterygoid vacuities were found on the palate and it had short and wide pterygoid from the ventral view.

[11] The caudal fin of Eurhinosaurus was in hypocercal shape (the notochord extended into the lower lobe) with cartilaginous chevrons which could be used for swimming in a high speed.

[3] In the vertebral column, the neural spins of the dorsal vertebrae were remarkably short, less than the height of the centrum, which was also found in other lower Jurassic large-bodied ichthyosaur such as Temnodontosaurus and Platypterygius.

[12] The elongated, densely toothed upper jaw was used as weapon to penetrate or make damage to small soft prey from the back.

[12] Their hypocercal caudal fin, which was mounted on the narrow peduncle, moved through the water in a sinuous curve by the powerful muscles of the posterior trunk and the anterior tail region.

Eurhinosaurus had a very large orbit with sclerotic ring, a circular shaped bone that was embedded in their eye.

[5] The sclerotic ring was probably used to maintain the shape of their eyes against the high pressure in the deep sea while they were diving.

[citation needed] The big eye of Eurhinosaurus suggested that they had very good visual capacity, which helped them see clearly in the dark environment of the deep sea.

[12] Eurhinosaurus was not like other ichthyosaurs and marine reptiles of the early Toarcian which showed a distinct provinciality.

[4] Fossils of Eurhinosaurus were found in the limestone and wackestone concretions in England, the Benelux,[citation needed] France, Switzerland and in southern and northern Germany.