|The holotype in the State Museum of Natural History Stuttgart|
Smith & Vincent, 2010
(Fraas, 1910 [originally Plesiosaurus])
Meyerasaurus is known from the holotype SMNS 12478, articulated and complete skeleton which preserved the skull, exposed in ventral view. The skull has a length of 37 cm (15 in), and the animal is about 3.35 m (11.0 ft) in length. It was collected from the Harpoceras elegantulum-falciferum ammonoid subzones, Harpoceras falcifer zone, of the famous Posidonien-Schiefer lagerstätte (Posidonia Shale), dating to the early Toarcian stage of the Early Jurassic, about 183-180 million years ago.
Meyerasaurus was first named by Adam S. Smith and Peggy Vincent in 2010 and the type species is Meyerasaurus victor. It was originally classified as a species of Plesiosaurus, later as the second named species of Thaumatosaurus (defunct name, meaning "wonder reptile") and ultimately as a species of Eurycleidus or Rhomaleosaurus. The generic name honors the German palaeontologist Hermann von Meyer for proposing the generic name Thaumatosaurus.