 The astounding morphological adaptations, the decrease in size, and the dispersal to the Americas and extinction in Eurasia all occurred during this timespan.DNA-DNA hybridization results suggest that the main radiation of South American hummingbirds took place at least partly in the Miocene, some 12 to 13 million years ago, during the uplifting of the northern Andes.In 2013, a 50-million-year-old bird fossil unearthed in Wyoming was found to be a predecessor to both hummingbirds and swifts before the groups diverged.