We’ve known them as ancient, mythical, winged, pyromaniacal reptilian beasts with a flair for the dramatic and destructive. They have been a fixture in our lore, in some form or another, the world over. While most of these tales of dragons are fictional, or at least highly embellished, there is still a very strong chord of truth in them. The blaze-setting, screeching hell-drakes so common in storybooks have not existed for a very long time, and it is unlikely that Medieval humans actually had contact with them (this stands in contrast with unicorns, which went extinct in 1982 when the last specimen escaped from her enclosure and ingested some antifreeze). However, dragons have had a rich and colorful evolutionary history that dates back 225 million years, and their unique biology and rise and fall in biodiversity is worth discussing.