Kimmeridgian genus first appearances

Pliosaurus is the type genus (defining example) of the pliosaurs, one of the major group of the plesiosaurs, an extinct group of aquatic marine reptiles. It lived from the Upper Jurassic to the Lower Cretaceous in what is now Europe and South America. The first known fossil consists of a partial skeleton of an immature specimen collected by William Buckland in Market Rasen, England. Although initially mentioned in a 1824 paper by William Daniel Conybeare, it was not until 1841 that it was first formally described by Richard Owen as belonging to a new species of Plesiosaurus, before being given

Dryolestes is an extinct genus of Late Jurassic mammal from the Morrison Formation and the Alcobaça Formation of Portugal. The type species Dryolestes priscus is present in stratigraphic zones 2, 5, and 6.

Rotularia is an extinct genus of planispirally coiled fossil polychaete worms in the family Serpulidae. Owing to the gastropod-like shape of Rotularia, many authors in the past interpreted this genus as being sea snails in the family Vermetidae. Like many other members from Vermetidae the Rotularia is approximately 5 inches in length. This is an estimate from the 151 confirmed fossil discoveries.