Douzhanopterus

The Tiaojishan Formation was deposited approximately 160 million years ago. It is exposed in northeastern China and preserves a large number of pterosaurs that show the transition to the diverse, short-tailed pterodactyloid lineage. Douzhanopterus is one of those transitional pterosaurs, and is known from a single well-preserved specimen missing only the head described by Xiaolin Wang and colleagues in 2017. 

The single specimen is preserved in articulation, and is preserved on part and counterpart slabs of stone. Most bones are split in half, and their external texture is largely unknown. Based on bone fusion, the original authors considered the specimen to be an adult. 

The wingspan was about 75 cm (30 inches), about the same size as most crows. The neck vertebrae show a moderate elongation in comparison to earlier pterosaurs, and the tail is fairly short, about the same length as the torso. Like later short-tailed pterosaurs, Douzhanopterus has a long hand, and a short fifth toe. 

Wang and colleagues conducted a phylogenetic analysis to determine where Douzhanopterus lies in he family tree of pterosaurs. They determined that it was just outside of the diverse lineage known as the pterodactyloids, which first arose in the Late Jurassic and came to dominate the skies in the Cretaceous. Pterodactyloids can be easily identified by their short tails, but share a large number of other anatomical features. In addition to short tails, pterodactyloids have proportionally long heads and necks. In the skull, the bony nostril has merged with a large sinus in the snout known as the antorbital fenestra. They also have long hands, and have reduced or loss the fifth toe in the foot.

Douzhanopterus was found to be more closely related to the pterodactyloids than its contemporaries Darwinopterus and Wukongopterus. Both Darwinopterus and Wukongopterus have long skulls where the bony nostril has merged with the antorbital fenestra. They both retain longer tails than Douzhanopterus, more similar to earlier pterosaurs than the pterodactyloids. Although the skull of Douzhanopterus is unknown, it is likely that it was similar to Darwinopterus, long and low, with a merged bony nostril and antorbital fenestra. 

The environment of the Tiaojishan Formation was subtropical, made up of ginkgo forests dotted with lakes. There were nearby volcanoes that helped preserve fossils in exquisite detail. Douzhanopterus probably consumed fish, insects, or other invertebrates, like its closest relatives.