The lonchodectid pterosaur Lonchodectes compressirostris is known from a partial rostrum and partial mandible found in the Upper Cretaceous Chalk Formation of Kent, England. Despite such scrappy remains, Lonchodectes has been through several taxonomic changes since the species was originally named as a new member of the genus Pterodactylus by Richard Owen in 1851.
Subsequently, it was thought to be one of dozens of species of Ornithocheirus, and in 1914 the genus Lonchodectes was named by Reginald Hooley to house the species. However for most of the 20th century, the species compressirostris was considered the holotype species of the genus Ornithocheirus, but current scholarship has shown that the holotype species of Ornithocheirus is actually O. simus. Adding to the confusion, O. simus itself was given its own genus name, Criorhynchus, which is now considered to be a synonym of Ornithocheirus.
In the 19th and 20th century several additional species have been assigned to Lonchodectes, but all are now considered to be in different lonchodectid genera, or are no longer considered valid. The genus Lonchodectes translates to “lance biter” and the species compressirostris translates to “compressed rostrum.”
The only known specimen of Lonchodectes is based on portions of the rostrum and mandible that were found together, and may or may not be from the same individual. The rostrum fragment is from the middle portion of the snout, missing the tip and the skull behind the nasoantorbital fenestra. The fragment is approximately 11 cm (4.5 inches) long and 2.5 cm (1 inch) tall. It preserves 9 tooth positions, with each tooth position having a slightly raised margin. The mandibular fragment is about 5 cm (2 inches) long and 2 cm (0.8 inches) tall. It is remarkably tall and narrow and preserves 5 tooth positions.
Neither the upper or lower jaws preserve any sign of sagittal crests, unlike many other pterosaurs. Based on comparisons to the more complete possible lonchodectids Yixianopterus and Unwindia, the skull may have been about 25 cm (10 inches) long when complete, and the wingspan may have been about 180 cm (6 feet). Our life reconstruction of Lonchodectes is largely based on Yixianopterus and Unwindia as well.
Lonchodectids are a mysterious lineage of Cretaceous pterosaurs largely known from snout fragments. They are characteristically long, somewhat tall, and quite narrow, and have teeth that emerge from small bony pedestals. Lonchodectes is found in sediments deposited under a warm and shallow sea about 95 million years ago. Lonchodectids may have fished, but their long and narrow snouts may have also been useful in probing tight spaces for small terrestrial prey.
In 2013 Taissa Rodrigues and Alexander Kellner considered Lonchodectes and therefore Lonchodectidae to be based on undiagnostic material, and erected Lonchodraconidae to house several species of pterosaurs with long and very narrow snouts and teeth emerging from bony pedestals. In 2017 Stanislas Rigal, David Martill, and Steven Sweetman published a paper that considered both Lonchodectes and Lochodectidae to be valid, and sunk Lonchodraconidae.
Rodrigues and Kellner performed a phylogenetic analysis and found that the lonchodectids, based on various species of Lonchodraco, were pterodactyloid pterosaurs, but without further resolution. Rigal, Martill, and Sweetman considered lonchodectids to be azhdarchoids of some kind, but did not perform a phylogenetic analysis. Several analyses performed by Brian Andres and colleagues have found Lonchodectes to be an ornithocheiroid, most recently finding lonchodectids to be most closely related to the boreopterids within the larger ornithocheiroid lineage.