Avebrevicauda

Avebrevicauda (meaning "birds with short tails") is a group which includes all avialan species with ten or fewer free vertebrae in the tail. The group was named in 2002 by Gregory S. Paul to distinguish short-tailed avialans from their ancestors, such as Archaeopteryx, which had long, reptilian tails.[1]

Avebrevicauda Temporal range: Early Cretaceous–Present, 131–0 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Fossil specimen of Sapeornis chaoyangensis, Hong Kong Science Museum
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Clade:	Dinosauria
Clade:	Saurischia
Clade:	Theropoda
Clade:	Euavialae
Clade:	Avebrevicauda Paul, 2002
Subgroups
†Zhongornis †Omnivoropterygiformes Pygostylia

The cladogram below follows the results of a phylogenetic study by Wang et al., 2016.[2]

Euavialae	†Jixiangornis   Avebrevicauda   †Sapeornis   Pygostylia   †Confuciusornis       †Chongmingia     Ornithothoraces

References

1. Paul, G.S. (2002). Dinosaurs of the Air. Baltimore: Johns Hopkins University Press. 460 pp.
2. Wang M., Wang X., Wang Y., and Zhou Z. (2016). A new basal bird from China with implications for morphological diversity in early birds. Scientific Reports, 6: 19700. doi:10.1038/srep19700.