Pterosaurs were flying reptiles that lived during the time of the dinosaurs, from the late Triassic to the end of the Cretaceous period. They are not classified as dinosaurs but are part of a group called archosaurs, which also includes crocodiles and birds. Pterosaurs had a wide range of sizes, from small, sparrow-sized species to the massive Quetzalcoatlus, which had a wingspan of over 30 feet. These creatures had unique adaptations for flight, including elongated wing membranes made of skin and muscle, supported by an extended fourth finger. Pterosaurs were diverse in their diets, with some being fish-eaters and others feeding on small land animals or even plants. Their fossils have been found on every continent, showcasing their global distribution during the Mesozoic era.