Motani, R. 1999 Journal of Vertebrate Paleontology 19 473-496 Petrolacosaurus Thadeosaurus Claudiosaurus Hovasaurus Hupehsuchus Utatsusaurus Grippia Parvinatator Chaohusaurus Cymbospondylus_petrinus Cymbospondylus_buchseri Mixosaurus_cornalianus Mixosaurus_atavus Mixosaurus_nordenskioeldii Besanosaurus Shastasaurus Shonisaurus Californosaurus Toretocnemus Hudsonelpidia Macgowanania Suevoleviathan Temnodontosaurus Leptonectes Excalibosaurus Eurhinosaurus Ichthyosaurus Stenopterygius Brachypterygius Opthalmosaurus Caypullisaurus Platypterygius Osteology Maximum Parsimony Based on reanalysis of the original matrix. Motani_1999a