Temnodontosaurus (Greek for “cutting-tooth lizard” - temno, meaning “to cut”, odont meaning “tooth” and sauros meaning “lizard”) is an extinct genus of ichthyosaur from the Early Jurassic period. It lived between 200 and 175 million years ago (Hettangian - Toarcian), and lived in what is now Europe (England, France, Luxembourg, Germany and Belgium) and Chile.[1] They lived in the deeper areas of the open ocean.[2] University of Bristol paleontologist Jeremy Martin described the genus Temnodontosaurus as “one of the most ecologically disparate genera of ichthyosaurs”.[3] Temnodontosaurus was one of the largest ichthyosaurs. Estimates of the maximum length of Temnodontosaurus have ranged from 9 m (29.5 ft)[4] to 12 m (39 ft).[5] The largest of these estimates rival the lengths of another giant ichthyosaur, Shonisaurus popularis, which was previously considered the largest ichthyosaur.[6] Temnodontosaurus is known for its incredibly large eyes which, at approximately 20 cm (8 in) in diameter, are believed to be the largest of any known animal.[7] It possessed a tail bend that was characteristic of Jurassic ichthyosaurs [8] and had many conical teeth filling its jaw that were set in a continuous groove.[8] The number of valid Temnodontosaurus species has varied over the years. Christopher McGowan in 1992 believed there to be around thirteen species in the genus Temnodontosaurus.[8] Michael Maisch in 2000 listed 5: T. platyodon, T. trigonodon, T. acutirostris, T. nuertingensis and T. eurycephalus as the valid species of Temnodontosaurus.[5]