A team of paleontologists from Russia and Germany has found more evidence that ichthyosaurs during the Mesozoic Era inhabited cold water in the northern latitudes. Ichthyosaurs were a group of marine reptiles superficially resembling dolphins that plied the seas in great numbers during the Jurassic and Cretaceous periods of geologic time.
Fossil remains of two individuals were studied in this research. The first, an ichthyosaur called Arthropterygius, was found in a museum collection in Moscow and was collected in the 1940s on a riverbank in northern Russia. The second specimen, an Ophthalmosaurus, an ichthyosaur named after its large eyes, was collected in 2013 near the Kanin Peninsula even farther to the north.
Remains of Arthropterygius and a related group have also been found in Arctic Canada and southern Argentina, suggesting that this type of ichthyosaur had a very wide geographic distribution. Ophthalmosaurus has been found most notably in North America and Europe. Both specimens are the first ichthyosaur discoveries in their genera in Russia. The Ophthalmosaurus specimen is the most northerly for its genus.