The name was erected as a genus of pterosaur and became a 'wastebasket taxon' for British Jurassic pterosaur remains until a recent revision. Rhamphocephalus comprises several named species, two of which are pterosaurian, but the type species - R. prestwichi - is based on remains now identified as a thalattosuchian.
The genus name was initially used to classify pterosaurs and later became a general category for Jurassic pterosaurs until recent taxonomic changes.  Rhamphocephalus includes several named species, two of which are confirmed pterosaur types, but the type specimen - R. prestwichi - is now recognized as belonging to a different group called thalattosuchians.