The detailed anatomy of Rhamphorhynchus II: braincase, pneumatics and jaws

This second contribution on Rhamphorhynchus based on an acid-prepared specimen provides a detailed description of the braincase, concentrating on the broken skull and its hollow bones, aiming to gather data on its pneumatisation for comparative studies between crocodiles, pterosaurs and dinosaur-birds. Computed tomographic (CT) scanning was performed to further explore these cavities in the skull bones, which are easily visible especially where the bones are broken. However, it has not been possible to observe their precise origin and connections. The skull regions where the pneumatisation is most evident are the paroccipital processes and the prootics from the endoskeletal braincase, but the precise form of the cavities is not clear, and their origin as paratympanic systems cannot be seen. CT scanning with better resolution might show more details of the skull pneumatics to be used in a phylogenetic analysis.