What is "thunnosauria"

Thunnosauria ( Greek for " tuna lizard" - thunnos meaning "tuna" and sauros meaning "lizard") is an extinct clade of parvipelvian ichthyosaurs from the Early Jurassic to the early Late Cretaceous ( Hettangian - Cenomanian) of Asia, Australia, Europe, North America and South America. Named by Ryosuke Motani, in 1999, it contains the basal taxa like Ichthyosaurus and Stenopterygius and the family Ophthalmosauridae. In thunnosaurs, the forefin at least twice as long as the hindfin.