Redescription of The ‘Lost’ Holotype of Suevoleviathan Integer (Bronn, 1844) (Reptilia: Ichthyosauria)

ABSTRACT The genus Suevoleviathan is one of the rarest and most phylogenetically problematic members of the Early Jurassic Posidonienschiefer Formation ichthyosaur fauna. Two named species have been referred to this genus, both from the Toarcian of Baden-Wurttemberg, Germany. The holotype of the first-described of the two, Suevoleviathan integer, was never properly figured and was considered lost or destroyed by all recent authors. This created uncertainty in the literature regarding the validity of the larger of the two species, Suevoleviathan disinteger. Here, I redescribe and figure the relocated holotype of Suevoleviathan integer and reevaluate characters proposed to separate the two taxa. I find little evidence for two species of Suevoleviathan in the Posidonienschiefer Formation and suggest that Suevoleviathan disinteger (Huene, 1926) is a junior synonym of S. integer (Bronn, 1844). Specimens historically referred to S. disinteger represent ontogenetically older stages of S. integer, as supported by...