Jixiangornis

Jixiangornis
Temporal range: Early Cretaceous, 124.5 Ma
↓
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Order: Saurischia
Suborder: Theropoda
Clade: Avialae
Clade: Euavialae
Genus: †Jixiangornis
Ji et al., 2002
Species: † J. orientalis
Binomial name
Jixiangornis orientalis
Ji et al., 2002

Jixiangornis is a genus of primitive avialans from the Early Cretaceous. Like later avialans, it had no teeth, but it also had a long tail, unlike modern birds. Since teeth were still present in some more advanced short-tailed avialans, Jixiangornis seems to have evolved its toothlessness independently of modern birds. The long forelimb (131% of hindlimb length) indicates at least some aerial ability. Jixiangornis is currently known only from a single specimen, a complete but juvenile skeleton. The fossil was found in the Yixian Formation near Beipiao City, western Liaoning, China.

Classification

The only known species, J. orientalis ("Oriental bird from the Yixian Formation"), was described in November 2002. Ji et al. (2002) considered Jixiangornis capable of stronger flight than either Archaeopteryx or Jeholornis. Their phylogenetic tree shows Jixiangornis forming a clade (called "Euavialae" by Ji et al.) with birds that excludes Archaeopteryx and Jeholornis (=Shenzhouraptor).

An alternative view was presented by Zhou Zong-He and Zhang Fu-Cheng in 2006. They classified both Jixiangornis and Shenzhouraptor as junior synonyms of Jeholornis prima, meaning that Jixiangornis cannot be more advanced than Shenzhouraptor. This approach, however, was problematical given the numerous differences between Jixiangornis and Shenzhouraptor/Jeholornis, and a phylogenetic analysis performed in 2014 found that it may actually be more closely related to short-tailed avialans (Pygostylia) than to Jeholornis, as originally thought.[1]

References

  1. ↑ Lefèvre, U.; Hu, D.; Escuillié, F. O.; Dyke, G.; Godefroit, P. (2014). "A new long-tailed basal bird from the Lower Cretaceous of north-eastern China". Biological Journal of the Linnean Society 113 (3): 790–804. doi:10.1111/bij.12343.

Sources

This article is issued from Wikipedia - version of the Monday, April 25, 2016. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.