>>52735320Not really. Birds are literally dinosaurs and are the closest extant relatives to crocodiles (much closer than other reptiles like turtles, snakes and lizards). While mammals are a part of the synapsid clade who were for the long time classified as reptiles, more recent research puts synapsids in a separate group that split off the branch that would eventually produce all other reptiles back in... Carboniferous, I think? And unlike birds, mammals have too many features reptiles don't share.
