Forgotten pterosaurs in Hungarian collections: first description of Rhamphorhynchus and Pterodactylus specimens

A mostly articulated and partially three-dimensionally preserved specimen of Rhamphorhynchus and an articulated right hindlimb of Pterodactylus were bought by Andor Semsey at the beginning of the 20th century for the Hungarian Geologial Institute. They were exhibited for a long period but have never been studied by pterosaur experts. Here we provide a detailed osteological description of these specimens focusing especially on the skeletal parts that show differences from those described in other specimens by previous authors. In Rhamphorhynchus these features are e.g. the presence of distal carinae on the teeth, four concave articulation surfaces on the right margin of the sternal plate, and a single articular surface on the proximal end of the tibia. Based on different long bone ratios and earlier studies related to the genus, the Rhamphorhynchus specimen is clearly referred here to R. muensteri. Morphology of some postcranial elements indicates a skeletally mature but not old and large animal. The absence of pneumatic foramina on the ventral side of the transverse processes of the first four dorsal vertebrae indicates that the pattern of skeletal pneumaticity was different from that described in another R. muensteri specimen (MGUH 1891.738) and suggests both an inter- and intraspecific variability of this feature. Based on the ratios of the elements and on the embedding slab the isolated but articulated right hindlimb is referred here to Pterodactylus sp. and the unfusion of the proximal tarsals with the tibia refer to a not completely adult individual.