GrrlScientist writes "One of the most contentious issues among scientists who study the evolution of birds is identifying precisely when the modern birds (Neornithes) first appeared. This is due to conflicts between the fossil record and molecular dating methodologies. But there is another way to address this discrepancy. Because the evolution of parrots and cockatoos reflects the evolution of the birds (Aves) themselves, studying the psittaciformes offers compelling insights into this mystery. Further, because psittaciformes generally are not migratory and because they tend to occupy discrete ranges, their ancient patterns of diversification are easier to discern than for many other taxonomic orders of birds that have dispersed widely."