Jianchangnathus was initially described based on a single fossil skeleton, holotypeIVPP V16866, recovered near Linglongta, in Jianchang County. The second specimen, PMOL-AP00028, consisting of a partially articulated skull and fragments of postcranial skeleton of a subadult individual, was described in 2014.[2]
Description
Autapomorphies of Jiangchangnathus include: a convex top margin of the lower jaw; a large front branch of the jugal; and the first three pairs of teeth of the lower jaws pointing strongly forwards. Its describers found it to share several features with Scaphognathus, including a high front end of the lower jaws, a pear-shaped lower temporal fenestra with the broad end below and teeth in the maxilla of the upper jaw that have a space equal to that of three toothsockets between them.[1] Additionally, undescribed fossils of a pterosaur referred to Jianchangnathus suggest that the color of its pycnofibers was brown.[3]
Phylogeny
Jianchangnathus was assigned by the describers to the Scaphognathidae by the describing authors,[1] which was corroborated by later phylogenetic analyses which included this taxon.[4][5]
^ abcdXin Cheng; Xiaolin Wang; Shunxing Jiang; Alexander W.A. Kellner (2012). "A new scaphognathid pterosaur from western Liaoning, China". Historical Biology. 24: 101–111. doi:10.1080/08912963.2011.635423. S2CID128539358.
^Chang-Fu Zhou (2014). "Cranial Morphology of a Scaphognathus-Like Pterosaur, Jianchangnathus robustus, Based on a New Fossil from the Tiaojishan Formation of Western Liaoning, China". Journal of Vertebrate Paleontology. 34 (3): 597–605. doi:10.1080/02724634.2013.812100.
^Li, Q., J.A. Clarke, K.-Q. Gao, C.-F. Zhou, Q. Meng, D. Li, L. D'Alba, and M.D. Shawkey. 2014. Melanosome evolution indicates a key physiological shift within feathered dinosaurs. Nature 507: 350-353.