Dorygnathus ("spear jaw") was a genus of rhamphorhynchid pterosaur that lived in Europe during the Early Jurassic period, when shallow seas flooded much of the continent. It had a short () wingspan, and a relatively small triangular sternum, which is where its flight muscles attached. Its skull was long and its eye sockets were the largest opening therein. Large curved fangs that "intermeshed" when the jaws closed featured prominently at the front of the snout while smaller, straighter teeth lined the back. Having two or more morphs of teeth, a condition called heterodonty, is rare in modern reptiles but more common in basal ("primitive") pterosaurs. The heterodont dentition in Dorygnathus is consistent with a piscivorous (fish-eating) diet. The fifth digit on the hindlimbs of Dorygnathus was unusually long and oriented to the side. Its function is not certain, but the toe may have supported a membrane like those supported by its wing-fingers and pteroids. Dorygnathus was according to David Unwin related to the Late Jurassic pterosaur Rhamphorhynchus and was a contemporary of Campylognathoides in Holzmaden and Ohmden.
Discovery
The first remains of Dorygnathus, isolated bones and jaw fragments from the Schwarzjura, the Posidonia Shale dating from the Toarcian, were discovered near Banz, Bavaria and in 1830 described by Carl Theodori as Ornithocephalus banthensis; the specific name referring to Banz. In 1831 however, Theodori reassigned the species to the genus Pterodactylus, therefore creating P. banthensis. The holotype, a lower jaw, is specimen PSB 757. The fossils were studied by Christian Erich Hermann von Meyer in 1831 and again by Theodori in 1852 when he referred them to the genus Rhamphorhynchus instead of Pterodactylus. In this period a close affinity was assumed with a pterosaur known from Britain, later named Dimorphodon. Some fossils were sent to a professor of paleontology in Munich named Johann Andreas Wagner. It was he who, having studied new finds by Albert Oppel in 1856 and 1858, after Richard Owen had named Dimorphodon concluded that the German type was clearly different and that therefore a new genus of pterosaur should be erected, which he formally named Dorygnathus in 1860, from Greek dory, "spear" and gnathos, "jaw". Much more complete remains have been found since in other German locales and especially in Württemberg, including Holzmaden, Ohmden, and Zell. One specimen, SMNS 81840, has in 1978 been dug up in Nancy, France. Dorygnathus fossils were often found in the spoil heaps where unusable rock was dumped from slate quarries worked by local farmers. Most fossils were found in two major waves, one during the twenties, the other during the eighties of the twentieth century. Since then the rate of discovery has slowed considerably because the demand for slate has strongly diminished and many small quarries have closed. At present over fifty specimens have been collected, many of them are preserved in the collection of the State Museum of Natural History Stuttgart, as by law paleontological finds in Baden-Württemberg are property of this Bundesland. Due to the excellent preserval of the later found fossils, Dorygnathus has generated much interest by pterosaur researchers, important studies having been dedicated to the species by Felix Plieninger, Gustav von Arthaber, and more recently Kevin Padian.
In 1971 Rupert Wild described and named a second species: Dorygnathus mistelgauensis, based on a specimen collected in a brick pit near the railway station of Mistelgau, to which the specific name refers, by teacher H. Herppich, who donated it to the private collection of Günther Eicken, a local amateur paleontologist at Bayreuth, where it still resides. As a result, the exemplar has no official inventory number. The fossil comprises a shoulder-blade with wing, a partial leg, a rib and a caudal vertebra. Wild justified the creation of a new species name by referring to the great size, with an about 50% larger wingspan than with a typical specimen; the short lower leg and the long wing.
Padian in 2008 pointed out that D. banthensis specimen MBR 1977.21, the largest then known, has with a wingspan of 169 centimetres an even larger size; that wing and lower leg proportions are rather variable in D. banthensis and that the geological age is comparable. He concluded that D. mistelgauensis is a subjective junior synonym of D. banthensis.