FIG. 1 in Pennaraptoran Theropod Dinosaurs Past Progress And New Frontiers

FIG. 1. Schematic phylogeny and approximate divergence times of the major crownward stem bird lineages (blue) and the deepest extant clades within crown birds (green). Most recent common ancestor (MRCA) of crown birds indicated by green node. Dashed lines indicate extant lineages whose time-scaled branch lengths are debated. Divergence times illustrated for crown birds roughly follow those of Prum et al. (2015), and those of stem birds follow (Longrich et al., 2011). Stem bird phylogeny and scale modified from Field et al. (2018a), with stem bird topology following (Field et al., 2018b). K-Pg boundary indicated by dashed red line and asteroid at ~66 Ma.