Response to Comment on Whole-genome analyses resolve early branches in the tree of life of modern birds

Mitchell et al. argue that divergence- time estimates for our avian phylogeny were too young because of an inappropriate maximum age constraint for the most recent common ancestor of modern birds and that, as a result, most modern bird orders diverged before the Cretaceous- Paleogene mass extinction event 66 million years ago instead of after. However, their interpretations of the fossil record and timetrees are incorrect.