Forfexopterus

Description

In September of 2016 paleontologists described the remains of a new species of pterosaur from Liaoning Province, China. The remains were discovered by a farmer who found them in Lower Cretaceous rocks of the Jiufotang Formation, dated to approximately 120 million years ago. This new species, named Forfexopterus jeholensis, is known from a mostly complete skull, and a partially articulated body with well preserved limb bones and' sternum. The name Forfexopterus jeholensis translates to "scissor wing from the Jehol" and refers to the skull's long narrow upper and lower jaws which look remarkably like an opened pair of scissors in the specimen. 

The skull of Forfexopterus is approximately 50 cm (1.6 ft) long and 10 cm (4 in) tall at its greatest height. The upper and lower jaws are remarkably straight and show no signs of a bony crest seen in many other pterosaurs. The teeth are very slender and slightly curved, number about 120 in total, and are restricted to the distal-most third of the upper and lower jaws. The longest teeth are in tooth positions 6-10, near the tips of the jaws. Proportions of the phalanges in the wing finger help distinguish Forfexopterus from all other known pterosaurs. Although the specimen is incomplete, comparison of Forfexopterus to its closest relatives indicates it had a wingspan of just over two meters (6.6 ft). 

The authors found Forfexopterus to be a member of the Ctenochasmatidae, a group of filter-feeding pterosaurs common in Upper Jurassic and Lower Cretaceous rocks found mostly in northern continents. Ctenochasmatids are characterized by very long skulls with a large number of narrow teeth sometimes restricted to the distal portions of their jaws. In many other ctenochasmatids the teeth are arraged in the spatulate or spoon-shaped pattern. Ctenochasmatids have been interpreted either as filter feeders that use their narrow teeth to strain food items out of shallow water or wading ambush predators that used the teeth like whiskers to sense movements of prey. 

The Ctenochasmatidae include the namesake genus, Ctenochasma as well as Gnathosaurus, both from the Jurassic of Germany; Huanhepterus and Beipiaopterus from the Early Cretaceous of China; and the highly unusual filter feeder Pteradaustro from the Early Cretaceous of Argentina. Ctenochasmatids are in turn most closely related to Pterodactylus, the firt pterosaur given a scientific name, and Cycnorhamphus, a pterosaur with bizarre jaws and teeth of unknown function. 

Forfexopterus is a member of the Jehol Biota, a world-famous lagerstätte preserving thousands of bird and other feathered dinosaur specimens living in a forested environment dotted with many small lakes. The Jehol Biota is preserved in the stratigraphically lower and temporally older Yixian Formation and the stratigraphically higher and temporally younger Jiufotang Formation. Forfexopterus is the only ctenochasmatid known from the Jiufotang Formation although several other ctenochasmatids are known from the Yixian Formation. Forfexopterus lived alongside the pterosaurs Guidraco, Sinopterus, and Chaoyangopterus; the theropod dinosaurs Microraptor, Confuciusornis, and Sapeornis; and the ornithischian dinosaur Psittacosaurus.