The null hypotheses of modern bird (Neoaves) relationships. (A) Metaves monophyly (based on Fain and Houde's 7th intron of the β-fibrinogen tree); (B) Paraphyly of Metaves and Coronaves (based on Cracraft 1981). The likelihood scores of these trees were compared using our complete mitochondrial genome data set and tree (B) was better by 618 log-likelihood units, (P < 0.0001; SH test).
Morgan-Richards et al. BMC Evolutionary Biology 2008 8:20 doi:10.1186/1471-2148-8-20