Evidence for predation of soft-bodied Cephalopods by Pterosaurs from the Late Jurassic Solnhofen Limestone of southern .
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Constraining the diets of extinct taxa is vital for understanding predator-prey relationships, reconstructing extinct food webs and for understanding the evolution of multi-trophic interactions. Fossilised gut and throat contents, known as content fossils, are perhaps the most renowned line of direct evidence for extinct predator-prey interactions. These fossils have greatly increased the known dietary ranges of many extinct clades, including carnivory in Mesozoic Mammals, and piscivory in Theropod Dinosaurs. However, well-preserved content fossils are extremely rare and there is an inbuilt bias towards preservation of ‘harder’ items (e.g. scales and shells) and towards items consumed immediately prior to death. Other direct lines of evidence used to infer diets include coprolites, regurgitalites, tooth marks from supposed feeding events, healed bite traces from failed predation attempts, (which sometimes contain embedded teeth) and the preservation of predators and prey together as a result of fatal encounters. These types of evidence are slightly more abundant than content fossils and are also useful for gaining unique insights into the foraging and feeding behaviours and the habitat preferences of both predators and prey. For example, the presence of bone regrowth in the damaged caudal neural spines in the Hadrosaurid Dinosaur Edmontosaurus has been interpreted as evidence of active predation by the large Theropod Dinosaur Tyrannosaurus rex and that Tyrannosaurus rex, consequently, was not an obligate scavenger. Inferring the taxonomic identities of predators and prey from these types of evidence, however, can be difficult.