Seeds may have saved birds from extinction. When the asteroid apocalypse hit 66 million years ago species that relied on leaves and flowers were out of luck. Those that could subsist on seeds however had an advantage.

See the source article by following the link below:Seeds may have saved birds from extinction. When the asteroid apocalypse hit 66 million years ago, species that relied on leaves and flowers were out of luck. Those that could subsist on seeds, however, had an advantage.