Archaeopteryx wasn't much to look at: a tiny, feathered pterosaur that weighed less than two pounds. But what it lacked in physical badassery, it made up for in evolutionary braun. This animal is the most famous transitional species between dinosaurs and modern day birds. While it was likely preyed upon by all sorts of predators, its descendants would be among the very few dinosaurs that would survive the KT extinction event to evolve into modern day birds. Surviving a comet that wiped out 75% of life on Earth? That's a badass birdie. Artwork by edface.