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