Anurognathus

Made somewhat famous by its portrayal in the 1999 BBC miniseries Walking With Dinosaurs, Anurognathus is yet another Solnhofen pterosaur genus. In the show it was shown somewhat similar to what it might have been in reality, but it was not a fully accurate image. 

From what we now know about it and its relatives, we can safely say that Anurognathus was unlike any of its contemporaries. It belongs to the Anurognathidae, a small family of pterosaurs limited to the Middle and Late Jurassic Periods. 

They are all small animals with wingspans less than a meter across, and with short heads, massive eyes and small teeth. Some researchers, such as Alexander Kellner, place them at the very base of the pterosaur family tree. 

While it is a non-pterodactyloid, it did not have the long, vaned tail of its more distant cousins. Instead, the short tails of the Anurognathidae probably gave them more maneuverability while hunting small, swift prey. They do have adaptations for hunting insects, such as their rather broad wings for maneuvering better, and their sharp, needle-like teeth for quickly impaling their prey. 

The large eyes of anurognathids suggest that they hunted in low light conditions. Some of the Solnhofen pterosaurs are presumed to have been nocturnal. They include the filter-feeding Ctenochasma and moderate-sized piscivore Rhamphorhynchus. In the meantime the smaller piscivore Pterodactylus and the predaceous Scaphognathus were probably diurnal. Anurognathus is thought to have been crepuscular, hunting inland at dusk. 

The only known species in the genus is A. ammoni, described by Ludwig Doderlein in 1923 on the basis of a rather crushed but complete skeleton found in a limestone slab. 

Doderlein’s specimen was actually just an impression of the skeleton. It was redescribed in 1975 by Peter Wellnhofer, who reconstructed the skull incorrectly. Another specimen, more complete and even smaller, was described by Chris Bennett in 2007. This fossil had its wings perfectly folded up close to its body, a pose seen in its relatives as he says, but not in other pterosaur genera. 

It is easy to reconstruct Anurognathus based on its relatives. We know that the much larger Chinese anurognathid Jeholopterus had fur-like filaments or pycnofibers extending across the wing membranes, especially along the edge of the wings. 

This would have muffled the animal’s wingbeats, allowing it to hunt with owl-like silence. Anurognathus had a wingspan just 50 centimeters across, but its total length was less than 10 centimeters from head to tail.