biomechanically impossible. Perhaps it pursued relatively large prey, in view of its reinforced jaw joints and relatively high bite force. Azhdarchidae are now understood to be terrestrial predators akin to ground hornbills or some storks, eating any prey item they could swallow whole. Hatzegopteryx was a robustly built predator of relatively large prey, including medium-sized dinosaurs. Alanqa may have been a specialist molluscivore. A 2021 study reconstructed the adductor musculature of skulls from pterodactyloids, estimating the bite force and potential dietary habits of nine selected species. The study corroborated the view of pteranodontids, nyctosaurids and anhanuerids as piscivores based on them being relatively weak but fast biters, and suggest that Tropeognathus mesembrinus was specialised in consuming relatively large prey compared to Anhanguera. Dsungaripterus was corroborated as a durophage, with Thalassodromeus proposed to share this feeding habit based on high estimated bite force quotients (BFQ) and absolute bite force values. Tapejara wellnhoferi was corroborated as a specialised consumer of hard plant material with a relatively high BFQ and high mechanical advantage, and Caupedactylus ybaka and Tupuxuara leonardii were proposed to be ground-feeding generalists with intermediate bite force values and less specialised jaws. Natural predators Pterosaurs are known to have been eaten by theropods. In the 1 July 2004 edition of Nature, paleontologist Eric Buffetaut discusses an Early Cretaceous fossil of three cervical vertebrae of a pterosaur with the broken tooth of a spinosaur, most likely Irritator, embedded in it. The vertebrae are known not to have been eaten and exposed to digestion, as the joints are still articulated. Reproduction and life history While very little is known about pterosaur reproduction, it is believed that, similar to all dinosaurs, all pterosaurs reproduced by laying eggs, though such findings are very rare. The first known pterosaur egg was found in the quarries of Liaoning, the same place that yielded feathered dinosaurs. The egg was squashed flat with no signs of cracking, so evidently the eggs had leathery shells, as in modern lizards. This was supported by the description of an additional pterosaur egg belonging to the genus Darwinopterus, described in 2011, which also had a leathery shell and, also like modern reptiles but unlike birds, was fairly small compared to the size of the mother. In 2014 five unflattened eggs from the species Hamipterus tianshanensis were found in an Early Cretaceous deposit in northwest China. Examination of the shells by scanning electron microscopy