Confuciusornithiformes

Confuciusornithiformes Temporal range: Early Cretaceous, 131–120 Ma PreЄ Є O S D C P T J K Pg N
Fossil specimen of Confuciusornis sanctus
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Clade:	Dinosauria
Order:	Saurischia
Suborder:	Theropoda
Clade:	Pygostylia
Clade:	†Confuciusornithiformes Hou et al., 1995
Genera[1]
†Eoconfuciusornis †Confuciusornithidae †Changchengornis †Confuciusornis †Jinzhouornis

Confuciusornithiformes is a group of beaked, long-winged avialans from the early Cretaceous Period of China.

Description

Confuciusornithiformes were generally very small, with large, robust forelimbs supporting long and narrow wing feathers. Their legs were relatively short compared to their forelimbs. All known species lacked teeth, and had small, pointed beaks covering the tips of their jaws. About half of all the confuciusornithid specimens, including representatives of all species, that have preserved feathers possess a pair of distinctive ribbon-like tail feathers, and possessed both shafted and non-shafted (downy) feathers.^[2]

Classification

Size of different genera, compared to a human.

The family Confuciusornithidae was first named by Hou et al. in 1995 to contain the type genus, Confuciusornis, and assigned to the order Confuciusornithiformes.^[3] The Confuciusornithidae was given a phylogenetic definition by Chiappe, in 1999, who defined it as a node-based clade to include only Changchengornis and Confuciusornis.^[4] Jinzhouornis was added to the Confuciusornithidae by Hou, Zhou, and Zhang in 2002,^[5] though it is generally considered a synonym of Confuciusornis today. In 2008, Zhang, Zhou and Benton assigned the newly described genus Eoconfuciusornis to the family.^[2] However, several analyses since then have found it to be a non-confuciusornithid confuciusornithiform.^[1]

Most confuciusornithids are known from the upper Jehol group, the Yixian Formation and Jiufotang Formation, dating from 125 to 120 million years ago. E. zhengi, however, predated the other confuciusornithids by 6 million years, dating to 131 Ma ago.^[6]

Cladogram following the results of a phylogenetic study by Jinghai O'Connor and colleagues in 2016:^[7]

Pygostylia	†Didactylornis †Sapeornis Ornithothoraces †Confuciusornithiformes †Eoconfuciusornis †Confuciusornis dui †Jinzhouornis zhangjiyingia †Confuciusornithidae †Changchengornis †Confuciusornis sanctus

References

1. O’Connor, J. K., Averianov, A. O., & Zelenkov, N. V. (2014). A confuciusornithiform (Aves, Pygostylia)-like tarsometatarsus from the Early Cretaceous of Siberia and a discussion of the evolution of avian hind limb musculature. Journal of Vertebrate Paleontology, 34(3): 647-656.
2. Zhang, F. -C.; Zhou, Z. -H.; Benton, M. J. (2008). "A primitive confuciusornithid bird from China and its implications for early avian flight.". Science in China Series D: Earth Sciences 51 (5): 625–639. doi:10.1007/s11430-008-0050-3.
3. Hou, L.; Zhou, Z.; Gu, Y.; Zhang, H. (1995). "Description of Confuciusornis sanctus". Chinese Science Bulletin 10: 61–63.
4. Chiappe, Luis M.; Shu-An, Ji; Qiang, Ji; Norell, Mark A. (1999). "Anatomy and systematics of the Confuciusornithidae (Theropoda:Aves) from the Late Mesozoic of northeastern China". Bulletin of the American museum of Natural History 242: 89.
5. Hou, L. H.; Zhou, Z. H.; Zhang, F. C.; et. al (2002). Mesozoic Birds from Western Liaoning in China. Shenyang, China: Liaoning Science and Technology Publishing House.
6. O'Connor, J.K., Zhou Z. and Zhang F. (In press). "A reappraisal of Boluochia zhengi (Aves: Enantiornithes) and a discussion of intraclade diversity in the Jehol avifauna, China." Journal of Systematic Palaeontology, (published online before print 16 December 2010). doi:10.1080/14772019.2010.512614
7. O’Connor, J.K., Wang X., Zheng X., Hu H., Zhang X., & Zhou Z. (2016). An Enantiornithine with a Fan-Shaped Tail, and the Evolution of the Rectricial Complex in Early Birds. Current Biology, 26(1): 114-119.