In 2008 Brian Andres and Ji Qiang named a new ctenochasmatid, Elanodactylus prolatus, from the Lower Cretaceous Yixian Formation of Liaoning Province, northeastern China. In 2010, Chang-Fu Zhou described a second specimen of the same species. The name references Elanus, the genus name for birds-of-prey known as kites, for its similarly shaped wings. The species name translates to “elongate” in Latin, and references the long second and third wing finger phalanges which give the pterosaur kite-like wings.
The original specimen described by Andres and Ji is partially articulated, missing the head and part of the neck, as well as the hips, legs, and tail. Although it’s missing its head, the skeleton is unlike any other known pterosaur. The cervical vertebrae are long, and superficially similar to the terrestrial hunting azhdarchids. In the wing, the second and third wing finger phalanges are much longer than usual. The second phalanx is 14% longer than the first, and the third phalanx is about the same size as the first. In most other pterosaurs, the wing phalanges decrease in length distally.
The second specimen is also partially articulated and missing its head and neck, but does preserve the hips, legs, and feet. It was referable to Elanodactylus because of the similar wing finger phalanx proportions. Both specimens are regarded as adults because of skeletal fusion, but are different sizes, with the wingspan of the first being 2.5 m (8 feet) and the second being 1.7 m (5 1/2 feet).
Andres and Ji found that Elanodactylus was a gnathosaurine ctenochasmatid, a result found in other phylogenetic analyses. Elanodactylus is most closely related to Huanhepterus from the Lower Cretaceous of Gansu, China; Plataleorhynchus from the Lower Cretaceous of the UK; and Gnathosaurus from the Upper Jurassic of Germany and the Lower Cretaceous of the UK.
All ctenochasmatids have long narrow snouts with dozens of needle-shaped teeth usually directed outward. They are thought to have been suspension feeders, using the teeth to strain small invertebrates from water, mud, and weeds. Elanodactylus lived about 120 million years ago in a lush, temperate forest. It was one of several suspension-feeding ctenochasmatids known from the Yixian Formation, relying on the numerous lakes, rivers, and swamps of the area.