Zhejiangopterus linhaiensis (Cai and Wei 1994), Late Cretaceous, ~80 mya, ~28 cm skull length, was originally considerd a nyctosaurid, then an azhdarchid (Unwin 2007). Here Zhejiangopterus was derived from a sister to the basal azhdarchid Chaoyangopterus and phylogenetically preceded Quetzalcoatlus.
Distinct from Chaoyangopterus, the skull of Zhejiangopterus was much larger relative to the body. The dorsal profile was straight anteriorly, then gently convex posteriorly. The back of the skull extended posteriorly, probably to anchor neck muscles to counteract the weight and moment of the ginormous skull.
The cervicals were elongated. The dorsals were reduced. The sacrals were enlarged.
The pectoral girdle and humerus were further reduced. The wing elements were more gracile. Digit II and III were subequal. Manual 3.1 was twice as long as m3.3.
The pelvis was larger and more robust, especially the posterior ilium which developed a high flange. The prepubis had a short stem and a convex ventral rim.
Considering the reduced size of the pectoral girdle and the huge size of the skull, Zhejiangopterus would have been the poorest flyer among pterosaurs after SoS 2428.
Haenimichnus tracks (Hwang et al. 2002) closely match the manus and pes of Zhejiangopterus.
See the pterosaur family tree here. |