Boreopterus cuiae JZMP 04-07-3 (Lü and Ji 2005) was a complete specimen derived from a sister to the the JZMP embryo and the Lebanon ornithocheirid. Boreopterus phylogenetically preceded Haopterus and Zhenyuanopterus.
Distinct from the JZMP embryo, the skull of Boreopterus had at least 27 teeth in each upper jaw. They were long, slender and closely spaced. The rostrum was relatively longer and lower with a larger portion anterior to the antorbital fenestra. The postorbital portion was reduced with a posteriorly leaning orbit, as in Istiodactylus. The suborbital skull descended and the quadrate leaned posteriorly.
The cervicals were longer with higher neural spines. The sacrals were shorter by more than half. The caudals were more robust.
The humerus was larger, extending nearly to the acetabulum. The ulna and radius were also larger relative to the metacarpus. Fingers I-III were smaller. When folded the wing tip was no taller than the skull. The distal wing phalanges were shorter.
The pelvis was tiny. The hind limb was more gracile, inluding a tiny foot.
The pterosaur family tree is here. |
