A new, virtually complete and articulated pterosaur specimen (IVPP V14188, Fig. 1), Sinopterus liii (Meng 2015; Jiufotang Formation, 120 mya), is considered a new species of a well known genus, Sinopterus. According to Meng, distinct traits include:
- large body size
- short beak
- high and short skull
- cranially sloping crest on premaxilla
- well developed hatchet-shaped deltopectoral crest of humerus
Only the abstract is in English. Meng also modifies the description of the genus Sinopterus (Fig. 3).
From the Meng abstract
“Studies on the cranial crest have resulted in the suggestion that the bony crest was ossified by a crest composed of soft tissue during the ontogeny. As a result, the variation of size and shape among various Sinopterus specimens may be related to ontogeny and sexual behavior. Consequently, the sole difference in the cranial crest morphology between Huaxiapterus and Sinopterus is not taxonomically diagnostic, thus we propose that Huaxiapterus and Sinopterus are synonymy. Frequent volcanic activity in this region has caused the mass mortality of vertebrates.”
So Meng is a lumper.
Unfortunately we have not been able to verify variation in size and shape (except for enlargement of a cranial crest) in any pterosaur during ontogeny — and none, so far, have been able to assigned to a gender unless an aborted egg is nearby. These observations, of course, are contra traditional pterosaur paradigms, but they do follow the data.
I would have given this specimen a new genus.
Based on the low resolution images provided and the great size difference, the new specimen (Fig. 4) appears to be sufficiently distinct to warrant its own genus — but then again, all those Pteranodon specimens are lumped into one genus.
Will the lumpers and splitters please get together?
Meng X 2015. A New Species of Sinopterus from Jehol Biota and Reconstraction of Stratigraphic Sequence of the Jiufotang Formation. A Thesis for the Master Degree of Science in the Graduate School of Chinese Academy of Sciences, directed by Wang X-L. (in Chinese)