Scientific American has an article about pterosaurs. It seems that they not the birds, which are dinosaurs, ruled the skies. Pterosaurs were the first vertebrates to evolve powered flight. They ranged in size from the size of a small plane to the size of a modern sparrow. Many had heads larger than their bodies... they were, in essence, flying jaws of death!
Unlike dinosaurs, which are survived today by birds, pterosaurs left behind no living descendants. As a result, all that paleontologists know about pterosaurs comes from the fossil record. And that record has been frustratingly fragmentary, leaving us with just a glimmer of their former glory and a host of questions about their bizarre anatomy and ill fate. Paleontologists have scratched their heads over these mysteries for decades. Now new fossil discoveries, combined with mathematical modeling methods in which anatomical structures are simplified just enough that equations of physical properties can be applied to get best estimates of strength, weight, speed, and so forth, are finally generating insights. And what scientists are finding is that pterosaurs were even more extraordinary than we ever imagined.