Kunpengopterus
Kunpengopterus is a genus of wukongopterid pterosaur from the middle-late Jurassic Tiaojishan Formation of northeastern China. The genus contains two species, the type species K. sinensis and K. antipollicatus.
History of discovery
K. sinensis is known from the holotype specimen IVPP V16047, an almost complete skeleton with complete skull and lower jaws recovered from rocks of the Tiaojishan Formation in Linglongta, Jianchang County, western Liaoning. The age of these layers is controversial. This compression fossil is of an adult individual. Aside from the bones some soft parts were also preserved and the remains of a possibly regurgitated fish.Kunpengopterus was named and described by Wang Xiaolin, Alexander Wilhelm Armin Kellner, Jiang Shunxing, Cheng Xin, Meng Xi and Taissa Rodrigues in 2010. The type species is Kunpengopterus sinensis. The generic name combines the Kun, a large fish or whale from Chinese folklore that could transform itself into the Peng, a gigantic colourful bird providing a mythological explanation of the northern lights, with a Latinised Greek pteron, "wing". The specific name refers to the Chinese origin.
In 2017, an additional specimen, IVPP V 23674, was referred and described. It consists of a skeleton with skull.
A second species of Kunpengopterus was described in 2021 by Xuanyu Zhou and colleagues, Kunpengopterus antipollicatus. The specific name is from the Ancient Greek anti "opposite" and pollex "thumb", and refers to the opposed first finger on the wing.
Description
Kunpengopterus sinensis has an elongated head, long. The cervical vertebrae too are relatively long. The naris is confluent with the antorbital fenestra, but these large openings are still partly separated by a broad and anteriorly directed processus nasalis which has itself a small vertical tear-shaped opening. A low bony crest is present on the skull, just behind the eyes; preserved soft tissue shows it was elongated by cartilage and a yellow discolouration indicates it was perhaps enlarged to the back by a skin flap. There is no sign of a crest on the snout or of a keel under the lower jaws. The back of the skull is rounded. Kunpengopterus has a long stiff tail. The fifth toe is also long and strongly curved.K. antipollicatus has an opposable pollux or thumb, which is rare amongst non-mammals.
Biology
Sexual variation
The first Kunpengopterus specimen in which sex could be confidently identified was specimen ZMNH M8802 in the collections of the Zhejiang Museum of Natural History, nicknamed "Mrs T", originally described by Lü Junchang and colleagues in January 2011 as a specimen of Darwinopterus. In 2015, Wang e.a. reassigned the "Mrs T" specimen to Kunpengopterus, and in 2021 it was classified as a specimen of the new species Kunpengopterus antipollicatus. This specimen was preserved with the impression of an egg between its thighs in close association with its pelvis. This specimen had a broad pelvis and lacked any evidence of a crest. The egg was probably expelled from the body during decomposition, and its association with the Kunpengopterus individual was used to support the hypothesis of sexual dimorphism.However, this hypothesis has been criticized. Pterosaur researcher Kevin Padian questioned some of the conclusions drawn by Lü et al., suggesting in a 2011 interview that, in other animals with elaborate display crests, the size and shape of the crests change dramatically with age. He noted that the "Mrs T" specimen may simply have been a sub-adult which had not yet developed a crest. Furthermore, a rigorous analysis of wukongopterid variation published in 2017 noted that crests among wukongopterids were subject to a large amount of individual variation, and that there was no consistent dimorphism in the pelvic anatomy of crested and uncrested wukongopterid specimens.