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New Chinese Early Cretaceous bird taxa...



Zhou Zong-He & Zhang Fu-Cheng, 2006. Mesozoic birds of China: a synoptic review. Vertebrata PalAsiatica 44 (1): 74-98. http://www.ivpp.ac.cn/pdf/magazine196.pdf

Abstract: A synoptic review of the discoveries and studies of the Chinese Mesozoic birds is provided in this paper. 40Ar/39Ar dating of several bird-bearing deposits in the Jehol Group has established a geochronological framework for the study of the early avian radiation. Chinese Mesozoic birds had lasted for at least 11 Ma during about 131 Ma and 120 Ma (Barremian to Aptian) of the middle and late Early Cretaceous. In order to evaluate the change of the avian diversity in the Jehol Biota, six new orders and families are erected based on known genera and species, which brings the total number of orders of Chinese Mesozoic birds to 15 and highlights a remarkable radiation ever since the first appearance of birds in the Late Jurassic. Chinese Early Cretaceous birds had experienced a significant differentiation in morphology, flight, diet and habitat. Further examination of the foot of *Jeholornis* suggests this bird might not have possessed a fully reversed hallux. However, the attachment of metatarsal I to the medial side of metatarsal II does not preclude trunk climbing, a pre-adaptation for well developed perching life of early birds. Arboreality had proved to be a ket adaptation in the origin and early evolution of bird flight, and the adaptation to lakeshore environment had played an equally important role in the origin of ornithurine birds and their near-modern flight skill. Many Chinese Early Cretaceous birds had preserved the direct evidence of their diet, showing that most primitive birds were probably mainly insectivorous and that specialized herbivorous or carnivorous (e.g., piscivorous) dietary adaptations had appeared only in later advanced forms. The only known Early Cretaceous bird embryo fossil has shown that precocial birds had occurred prior to altricial birds in avian history, and the size o the embryo and other analysis indicate it probably had a short incubation period. Leg feathers probably have a wide distribution in early birds, further suggesting that leg feathers played a key role in the beginning stage of the flight of birds. Finally, the Early Cretaceous avian radiation can be better understood against the backdrop of their unique ecosystem. The advantage of birds in the competition with other vertebrate groups such pterosaurs had probably not only resulted in the rapid differentiation and radiation of birds but also the worldwide speading of pterosaurs and other vertebrates from Easy Asia in the Early Cretaceous.

New "orders" and "families" named in this paper:

Jeholornithiformes
Jeholornithidae
Sapeornithiformes
Sapeornithidae
Boluochiformes
Boluochidae
Protopterygiformes
Protopterygidae
Longirostravisiformes
Longirostravisidae
Yixianornithiformes
Yixianornithidae

No phylogenetic definitions, and they all currently contain just a single species. *Otogornis genghisi* seems to be listed as a longirostravisid in a table, perhaps by error, because only *Longirostravis hani* is listed as an included taxon in the diagnosis of Longirostravisiformes/idae. *Shenzhouraptor* and *Jixiangornis* are both said to be junior synonyms of *Jeholornis*. A recent discovery of a jeholornithiform bird in the Yixian Formation is mentioned, but not yet described.