What is "macropterygius"

Macropterygius is a genus of ichthyosaurs known from the Late Jurassic ( Kimmeridgian age) of England ( Kimmeridge Clay formation). Though many specimens have been referred to this genus from all over Europe, the type specimen of the only recognized species, M. trigonus, consists of just a single vertebra. Because this cannot be used to distinguish ichthyosaurs from one another, the genus and species are currently considered nomena dubia (doubtful names).