[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]
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.