[3] Per Ericson and colleagues, in analysing genomic DNA, revealed a lineage comprising passerines, psittacines and Falconiformes.

[4] The group was proposed following an alignment of nuclear intron sequences by Shannon Hackett et al. in 2008.

[5] It was formally named as Psittacopasserae in a 2011 Nature Communications article by Alexander Suh and other authors working with Jürgen Schmitz's group,[6] based on genetic analysis of the insertion of retroposons into the genomes of key avian lineages over the course of evolution during the Mesozoic Era.

[3] [clarification needed] Passerines are renowned as songbirds (technically this word refers to a clade of passerines), and parrots share a capacity for vocal learning.

Thus it is possible that vocal learning, and the corresponding variety of song, was present in a psittacopasseran ancestor.