Over a few years, several small blocks of limestone with pterosaur bones were found in Upper Triassic rocks of the Karwendel Mountains in the Northern Calcareous Alps of western Austria. In total, 5 small contiguous blocks of limestone were discovered that bore the partial and disarticulated skeleton of a small pterosaur. The skeleton was first described in detail by Peter Wellnhofer in 2003, and thought to probably be a juvenile specimen of Eudimorphodon ranzii, known from contemporaneous rocks in northern Italy, because of similar teeth. In the same year, Fabio Marco Dalla Vecchia considered it to be a distinct genus and species from Eudimorphodon ranzii. In a 2015 review of Triassic pterosaurs, Alexander Kellner named a new genus and species for the specimen, Austriadraco dallavecchiai, honoring both Austria and Dalla Vecchia.
Together the limestone blocks are about 60 cm (24 inches) by 20 cm (8 inches), with the disarticulated skeleton spread across all five blocks. The bones include both lower jaws and teeth, and isolated portions of the cheek and skull roof; some neck, torso, and tail vertebrae; ribs; both shoulders and portions of both wings; and parts of the hips and legs. The lower jaws are mostly complete lacking only the tips, and were about 4 cm (1 1/2 inches) long and would have been 5-6 cm (2 - 2 1/2 inches) long when complete. The right jaw is most complete and includes 12 teeth and at least 3 empty tooth sockets. The teeth are laterally compressed and superficially leaf shape with 5 cusps or denticles on each tooth.
Like other Triassic pterosaurs, Austriadraco had a long tail, but unlike many other long-tailed pterosaurs its tail was pretty flexible, lacking the long overlapping extensions that stiffened the tails of most other early pterosaurs. The limb bones have distinctive proportions compared to other Triassic pterosaurs, with longer legs compared to its wings than many others. The only known individual was nearly fully grown, but a small animal with its wingspan estimated to be about 80 cm (about 2.5 feet).
When Austriadraco was alive, about 210 million years ago, most of the world’s continents were joined in the ancient supercontinent Pangaea. Europe was much further south, at a tropical latitude. It was on the northern shore of the Tethys Ocean, and had many low-lying islands, reefs, and lagoons. The multi-cusped teeth of Austriadraco and other early pterosaurs have been interpreted as ideally suited to eating insects, crustaceans, and other small invertebrates, but may have also been suited to eating fish.
Wellnhofer originally considered the specimen to be a juvenile individual of Eudimorphodon, and a member of the early pterosaur family, Eudimorphodontidae. In 2009, Dalla Vecchia performed a phylogenetic analysis of Triassic pterosaurs and found that specimen was not closely related to Eudimorphodon, but actually a member of one of the earliest branching pterosaur lineages that also includes Arcticodactylus from Greenland. He also found that Eudimorphodon and many others usually considered to be eudimorphodontids were actually campylognathoidids, most closely related to Campylognathoides from the Lower Jurassic.
When Kellner named the genus and species in 2015, he also named a new family, Austriadraconidae, to house it and possibly Arcticodactylus. Other pterosaur phylogenetic analyses, including a 2018 analysis by Longrich, Martill, and Andres have found that eudimorphodontids do form a natural group of strictly Triassic pterosaurs called eopterosaurs, although they did not include Austriadraco itself in the analysis. The eopterosaurs also include Austriadactylus, Peteinosaurus, and Preondactylus, but excludes Campylognathoides which was found to be more closely related to all other pterosaurs than to the eopterosaurs.
