Modern birds diversified after dinosaurs became extinct 66m yrs ago

A new study has provided a deeper insight into how birds evolved so quickly after dinosaurs disappeared 66 million years ago.

An international collaboration of scientists worked for four years to sequence, assemble and compare the full genomes of 48 bird species representing all major branches of modern birds. It was the largest whole genomic study across a single vertebrate class ever undertaken.

The research helped confirm that some of the first lineages of modern birds appeared about 100 million years ago but that almost all of the modern groups of birds diversified in a small window of less than 10 million years, just after the dinosaurs were wiped out by an asteroid.

Professor Ho said that the team was able to work out the relationships among the major groups of modern birds, showing that the earlier understanding of birds had been clouded by the appearance of similar traits and habits in distantly related groups.

So while grebes and cormorants are both waterbirds with webbed feet that dive to catch their prey they are, despite these similarities, from completely distinct lineages, he further added.

Another significant finding was that the ancestor of most of the land birds that are seen today was probably an apex predator that gave rise to raptors, eagles, owls and falcons in rapid succession before leading to land birds such as songbirds and woodpeckers.

Professor Ho further concluded that with the demise of the dinosaurs, birds and mammals were able to become more diverse and to occupy all of the niches that had previously been dominated by dinosaurs.

The study is published in a special edition of Science.