Ctenochasmatoidea is a group of pterosaurs within the suborder Pterodactyloidea. It was defined by Unwin (2003) as the clade containing Cycnorhamphus suevicus, Pterodaustro guinazui, their most recent common ancestor, and all its descendants. The earliest known ctenochasmatoid remains date to the Late Jurassic Kimmeridgian age. Previously, a fossil jaw recovered from the Middle Jurassic Stonesfield Slate formation in the United Kingdom, was considered the oldest known. This specimen supposedly represented a member of the family Ctenochasmatidae, though further examination suggested it actually belonged to a teleosaurid stem-crocodilian instead of a pterosaur.