Chaoyangopterids are distinguished from other pterosaurs by several traits of the nasoantorbital fenestra, a large hole on the side of the snout formed by the assimilation of the nares (nostril holes) into the antorbital fenestra. In members of this family, the nasoantorbital fenestra is massive, with the rear edge extending as far back as the braincase and jaw joint. The front edge is formed by a rod of bone known as the premaxillary bar, which is unusually slender in members of this family.[8]
Classification
Below is a cladogram showing the phylogenetic analysis conducted by paleontologist Brian Andres and colleagues in 2014. In the analysis, Chaoyangopteridae was found to consist of the genus Eoazhdarcho and the subfamily Chaoyangopterinae.[11] The subfamily Chaoyangopterinae was initially used by paleontologist Felipe Pinheiro and colleagues in 2011, which they assigned to the family Tapejaridae,[12] however, Andres and colleagues redefined the subfamily as the least inclusive clade containing Chaoyangopterus zhangi and Shenzhoupterus chaoyangensis. In the analysis by Andres and colleagues, Chaoyangopterinae consisted of the pterosaurs Chaoyangopterus, Shenzhoupterus, and Jidapterus.[11]
Like their azhdarchid relatives, pterosaurs that belong to the Chaoyangopteridae were terrestrial predators.[14][15]
Paleoecology
The members of the family Chaoyangopteridae are mostly known from Asia, though the possible member Lacusovagus occurs in South America[10] and there are possible fossil remains from Africa, including the possible member Apatorhamphus.[16]Microtuban may extend the clade's existence into the early Late Cretaceous.[14]
^Pêgas, R.V.; Holgado, B.; Ortiz David, L.D.; Baiano, M.A.; Costa, F.R. (21 August 2021). "On the pterosaur Aerotitan sudamericanus (Neuquén Basin, Upper Cretaceous of Argentina), with comments on azhdarchoid phylogeny and jaw anatomy". Cretaceous Research. doi:10.1016/j.cretres.2021.104998.
^ abWilton, Mark P. (2013). Pterosaurs: Natural History, Evolution, Anatomy. Princeton University Press. ISBN0691150613.
^Wen-Hao Wu; Chang-Fu Zhou; Brian Andres (2017). "The toothless pterosaur Jidapterus edentus (Pterodactyloidea: Azhdarchoidea) from the Early Cretaceous Jehol Biota and its paleoecological implications". PLoS ONE. 12 (9): e0185486. doi:10.1371/journal.pone.0185486.