The
type species is
R. pellati, described by Sauvage in 1883. When first described, Sauvage classified it as a
dinosaur. Later,
Franz Nopcsa referred the genus to
Anchisauridae, while
Karl Alfred von Zittel referred it to either
Zanclodontidae or
Megalosauridae. The ichthyosaur nature of
Rachitrema was recognized by
Friedrich von Huene, who synonymized it with
Shastasaurus. Sauvage conceded that
Rachitrema was non-dinosaurian, and the ichthyosaur classification of the genus became universally accepted by several authors. McGowan and Motani (2003) considered
Rachitrema dinosaurian without comment. However, recent re-examination of the type material of
Rachitrema reaffirms the ichthyosaurian classification of the genus, with most of the original remains referable to Ichthyosauria, and the rest being indeterminate beyond Reptilia. ==References==