deinonychosaurian

Although this particular result may be due to the limited sampling of avian taxa, the presence of a deinonychosaurian key feature (a hyperextendible second toe) and the absence of two avian key features a triradiate palatine (3) and a fully reversed first toe in Archaeopteryx challenges the monophyly of Aves as currently recognized.

New Archaeopteryx fossil provides further insight into bird, dinosaur evolution - The Panda's Thumb 2005

The analysis using a 2004 version of the Theropod Working Group matrix, a matrix unsuited for testing the relationships of birds, and only three avian OTUs only finds that Confuciusornis is a deinonychosaurian, or in their words, that it challenges the monophyly of Aves as currently recognized.

New Archaeopteryx fossil provides further insight into bird, dinosaur evolution - The Panda's Thumb 2005