Two emetolite-pterosaur associations from the Late Jurassic of China: showing the first evidence for antiperistalsis in pterosaurs

Abstract

Knowledge about the pterosaur diet and digestive system is limited, and there is little direct evidence in the fossil record. Here, we report two specimens of the wukongopterid Kunpengopterus sinensis , a juvenile and an adult, from the Late Jurassic Yanliao Biota of China with associated bromalites. Both of these concentrations are identified as emetolites, fossilized gastric pellets. These pellets contain scales of an unnamed palaeonisciform fish, confirming the pterosaur was a piscivore. It probably vomited the pellets, indicating the presence of two-part stomachs and efficient antiperistalsis in both juveniles and adults. Comparing the ganoid scales found in the pellets with those of complete fishes, it was possible to determine that the prey of the smaller pellet is an average-sized individual, while the prey of the larger pellet represents a large specimen. Kunpengopterus sinensis might have preyed on the same fish during ontogeny, with adults being able to feed on larger individuals. This article is part of the theme issue ‘The impact of Chinese palaeontology on evolutionary research’.

Evolutionary pressures of aerial insectivory reflected in anurognathid pterosaurs

“…However, various extant insectivorous birds are capable of ingesting and digestion chitinous-rich and hard-bodied insects, despite a lack of oral processing (e.g., Galbulidae, the jacamars) (Sazima, 2015) which notably produce egested pellets. At least some early pterosaurs also produced pellets of indigestible fish scales (Jiang et al, 2022), and so if anurognathids diets consisted heavily of hard-bodied prey items, occluded. We do not consider a lack of analogous features in extant wide-mouthed insectivores as a refutation since all extant birds are edentulous.…”

“…However, various extant insectivorous birds are capable of ingesting and digestion chitinous‐rich and hard‐bodied insects, despite a lack of oral processing (e.g., Galbulidae, the jacamars) (Sazima, 2015) which notably produce egested pellets. At least some early pterosaurs also produced pellets of indigestible fish scales (Jiang et al, 2022), and so if anurognathids diets consisted heavily of hard‐bodied prey items, they might also have been regurgitators. Anurognathid teeth could though likely pierce softer‐bodied prey, and perhaps function secondarily to keep prey within the mouth once engulfed, preventing escape, particularly when considering that gape morphology would allow for uniform closure when the “U‐shaped” mouth became fully occluded.…”