Frequency of non-mineralized biomaterials preservation in the fossil record of Mesozoic reptiles: an approach on pterosaurs and marine reptiles

In the last few decades, several studies have found exceptional preservation of different original biomolecules in dinosaurs. However, distinct groups of reptiles that dominated airs, seas and oceans in the Mesozoic Era, such as pterosaurs, ichthyosaurs, mosasaurs, notosaurs and plesiosaurs, present scarce data regarding non-mineralized biomaterialsfindings and those that have already been identified are dispersed in the literature, associating the idea of discoveries with isolated phenomena. Thus, this article presents a review of the literature published in the last twodecades, in order to better understand the frequency of claimed non-mineralized biomaterialsfindings in fossils of reptiles from the Pterosauria clade and marine reptiles from the Lepidosauromorpha clade of the Mesozoic Era, often mistaken for dinosaurs by the popular imaginary. The results identified 3 studiesdescribing preserved organic material for representatives of Pterosauria. For marine reptiles of the Lepidosauromorpha clade, were found 8studies, with findings distributed amongthe Ichthyosauria, Mosasauria, Nothosauroidea and Plesiosauria. In general, the data for such groups were not geographically and taxonomically comprehensive in Mesozoic rocks. However, it is believed that the frequency is underreported, and from the emergence of new technologies, the forecast is that fossil biochemistry will be more frequently characterized.