Thoracopterus had elongate pectoral fins, similar to modern Exocoetidae, which are used to glide overwater in order to escape aquatic predators. Thoracopterus represents one of the earliest known example for overwater gliding in actinopterygians.
Wildlife of Gondwana: Dinosaurs and Other Vertebrates from the Ancient Supercontinent (Life of the Past) by Pat Vickers Rich, Thomas Hewitt Rich, Francesco Coffa, and Steven Morton
The Rise of Fishes: 500 Million Years of Evolution by John A. Long