On the cervical vertebrae of the Pterodactyloidea (Reptilia: Archosauria)

Within the Pterodactyloidea, the cervical vertebrae show considerable variation. These elements are also sufficiently common and contain enough anatomical information to make them taxonomically valuable. A survey of these vertebrae concludes that most known pterodactyloids fall into two groups: long-necked forms with attenuated cervical vertebrae that possess low neural spines, and tall-spined forms that possess relatively short neck vertebrae with tall neural spines. These two groups may represent natural taxonomic units. However, this is by no means conclusive and can only be tested by the study of other regions of pterodactyloid skeletons.