Aegirosaurus

Aegirosaurus  is an extinct genus of ichthyosaur, a fish-like marine reptile, from the Tithonian (Upper Jurassic) of Bavaria, Germany. Its remains were discovered in the Solnhofen limestone formations, the same formations that have yielded numerous well-known fossils, such as Archaeopteryx, Compsognathus and Pterodactylus.

Discovery and species
Originally described by Wagner (1853) as Ichthyosaurus leptospondylus, it has had an unstable taxonomic history. It has also been named Ichthyosaurus trigonus posthumus, and identified with Macropterygius and Brachypterygius extremus. In 2000 Bardet and Fernández concluded that the fossil material should be assigned to a new genus, Aegirosaurus. The name means 'Aegir (teutonic god of the ocean) lizard with slender vertebrae'.

Within Ophthalmosauridae, Aegirosaurus is most closely related to Ophthalmosaurus.

Palaeobiology
It was a small genus of ichthyosaur, with adults being less than two metres in length.