A corrected version of the paper. Only the first part of the name was changed ("versper" to "vesper"). The "pteryl" part was left as-is. As I discussed in a posting, the spelling "pterylus" meets ICZN requirements to be interpreted as a Latin nominative singular ending. Possible sources could be a rare Greek diminutive suffix -ylos (as in Greek *arktylos* "bear cub"), or from Greek *hyle* "forest" (as in Greek *polyylos* "abundant in forests"), or perhaps short for *hylobios* "forest-living." The ICZN rules don't require that names be necessarily well formed according to classical rules apart from the ending. A fair number of Neo-Latin zoological names are formed in nonclassical ways, with abbreviated terms to shorten the spelling.
Junchang Lü, Qingjin Meng, Baopeng Wang, Di Liu, Caizhi Shen and Yuguang Zhang (2017)
Short note on a new anurognathid pterosaur with evidence of perching behaviour from Jianchang of Liaoning Province, China.
Geological Society, London, Special Publication SP455: New Perspectives on Pterosaur Palaeobiology (advance online publication)
A new anurognathid pterosaur, Vesperopterylus lamadongensis gen. et sp. nov., is erected based on a complete skeleton with a skull preserved. It is characterized by two short distinct ridges present on the ventral surface of the cervical vertebrae; coracoids slightly longer than scapula; humerus, wing phalanx 3 and tibia nearly the same in length; grooves clearly present on the posterior surface of the wing phalanges 1–3; and the first toe reversed. It is the first anurognathid pterosaur from China with a definitively short tail, and the first pterosaur with a reversed first toe. The reversed first toe of Vesperopterylus indicates that it had arboreal habitats. The discovery of Vesperopterylus lamadongensis from the Jiufotang Formation strongly expands the geological age range for anurognathid pterosaurs.