As if hurried by the process of discovery and the level of achievement gained through the recovery and description of Darwinopterus (details summarized here),researchers have uncovered yet another long-tailed, large-skulled “intermediate” between the rhamphorhynchoid and pterodactyloid grades of pterosaur, Wukongopterus lii.
Wang X.-l., A. W. A. Kellner, Jiang S.-x. and Meng J. 2009. An unusual long-tailed pterosaur with elongated neck from western Liaoning of China. Anais da Academia Brasileira de Ciências 81(4):793-812.
As this transistory grade of pterosaurs grows, first uncovered with Pterorhynchus and then earlier this year by Darwinopterus, the complex development of the origin of the pterodactyloid morphotype — including the potential for it to have developed convergently in two different groups — increases and belittles some of our understanding of the linearity of evolution.
Wukongopterus differs very little from Darwinopterus, but where it differs is primarily in the mandible and dentition (most of the cranium is missing in the only known specimen, IVPP V15113), which is unusual as this region is very similar to Pterorhynchus. The mandible is robust and deep compared to its length, although this may be little more than a preservational artefact as rotation of the bone and lack of crushing (potentially present in Darwinopterus and Wukongopterus) could result in the perceived differences.
Peculiarly, Wukongopterus is much like Pterorhynchus in that it produces a robust mandible and short teeth, but skeletally it is much more like Darwinopterus, and some may even suggest that they are synonymous.
As time goes on, it may become even more convoluted, depending on whether one scores these features in their analyses differently, or whether one reads any distinctiveness among specimens as skeletally unimportant save for the general features these two taxa seem to share. Nonetheless, an interesting pair of pterosaurs.