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 a teleosaurid stem-crocodilian instead of a pterosaur.
Pereda-Suberbiola et al. (2012) use Fabien Knoll's (2000) definition of Pterodactylidae; Knoll defined Pterodactylidae as a clade containing "Pterodactylus antiquus, Ctenochasma elegans, their most recent common ancestor and all [its] descendants". The analysis conducted by Pereda-Suberbiola et al. (2012) indicated that Ctenochasmatoidea is nested within such defined Pterodactylidae; other analyses, such as Unwin's (2003) make such defined Pterodactylidae nested within Ctenochasmatoidea instead.
^ abcUnwin, D. M., (2003). "On the phylogeny and evolutionary history of pterosaurs." Pp. 139-190. in Buffetaut, E. & Mazin, J.-M., (eds.) (2003). Evolution and Palaeobiology of Pterosaurs. Geological Society of London, Special Publications 217, London, 1-347.
^Buffetaut, E. and Jeffrey, P. (2012). "A ctenochasmatid pterosaur from the Stonesfield Slate (Bathonian, Middle Jurassic) of Oxfordshire, England." Geological Magazine, (advance online publication) doi:10.1017/S0016756811001154