Aurornis
- Tiaojishan Formation ( China)
- Aurornis xui Godefroit et al., 2013
Aurornis is a genus of theropod dinosaurs ( theropods ). Your only way Aurornis xui, lived during the Jurassic (about 152.1 to 166.1 mya ) in eastern Eurasia. The approximately 50 cm long Aurornis was probably fully feathered, but probably only for gliding in the situation. The genus description is based on fossil material that was found early 21st century in northeast China Tiaojishan lineup. The genus was first described in 2013 by a research group led by Pascal Godefroit. They arranged as the oldest and most authentic representative of the Avialae, including the birds ( Aves) and its closest relatives.
Features
Aurornis xui was a relatively small theropod with about 50 cm body length. The skull of the holotype is 57 mm long, its tail is compared with that of other basal Paraves very long ( about four times as long as the thigh bone). The arms of the kind were relatively long, reaching about 80% of leg length. The body was covered with fine feather fluff; legs, arms and tail possessed A. xui probably like other Paraves long shaft springs. The feathered arms were possibly taken to help the animals during running and jumping.
Ecology
Aurornis xui probably lived in a warm and temperate to subtropical climate, which was characterized by high humidity. His prey he hunted probably constantly.
Fossil material, stratigraphy and distribution
The fossil material from Aurornis includes the complete skeleton of an individual, which is embedded in a slate. The specimen was found at the beginning of the 21st century in commercial excavations near Daxishan in the Chinese province of Liaoning. It comes from the Tiaojishan lineup and came across a fossil dealers in the possession of Yizhou Fossil & Geology Park, where it is conducted under the inventory number YFGP - T5198. The age of the specimen is difficult to determine: the Tiaojishan formation has a complex stratigraphy, individual pieces can only be through extensive microfossil analysis datieren.Chronostratigraphische studies of the formation arrange them in a period of 165 ± 1.2 to 153 ± 2 mya one. Aurornis xui had lived thus in the Callovian ( Middle Jurassic ) or Kimmeridgian ( Upper Jurassic ). At the time, the location was on the western edge of Eurasia, which was isolated by the northern shelf seas of the Tethys from North America and Gondwana.
Systematics and Taxonomy
Aurornis
Xiaotingia
Shenzouraptor
Balaur
Troodontidae
Dromaeosauridae
The skeleton of the Tioajishan formation was investigated by Pascal Godefroit, Andrea Cau, Hu Dong- Yu, François Escuillié, Wenhao Wu and Gareth Dyke and 2013 determined the holotype of a new genus and species. Based on a phylogenetic analysis of 101 taxa based on 992 osteological characters they arranged the fossil one at the base of Avialae, so the most extensive kinship group including the birds, but not the Troodontidae and Dromaeosauridae. At the same time the analysis situate the genus Archaeopteryx, whose membership was provided to the birds previously by Xu Xing and colleagues in question, are also within the Avialae. From the perspective of authors is Aurornis thus the oldest and most authentic bird in a broader sense, whereas the precursor position of Archaeopteryx was underpinned. The authors chose the generic name Aurornis ( Latin for " aurora" Dawn, Greek " ornis " for bird ) according to the age and original position in the bird family tree. The specific epithet xui they devoted Xu Xing, whose phylogenetic hypotheses, although they disagreed in their article, they nevertheless paid tribute of respect for his research on Mesozoic birds and their closest relatives.