FIGURE 12 in Phylogenetically vetted and stratigraphically constrained fossil calibrations within Aves

FIGURE 12. Stratigraphic distribution of fossil Pan-Psittaciformes in the Paleogene. The minimum possible age of the calibrating specimen NMH A6207 is presented, and midpoints of age ranges are shown for the ages of other Paleogene parrot specimens. Note that the London Clay Formation also contains multiple associated skeletons and isolated bones in addition to the holotype of Pulchrapollia gracilis that serves as a calibration point.