The largest flying reptile from the Crato Formation, Lower Cretaceous, Brazil

摘要

The Early Cretaceous deposits of the Araripe Basin in northeast Brazil has yielded numerous vertebrate fossils, in which pterosaurs are the predominant tetrapods. Almost all specimens of this extinct group of flying reptiles recovered from this basin come from two stratigraphic units, the Crato and Romualdo Formations, with the pterosaurs from the former being usually small to middle-sized and large individuals (with a maximized wingspan over 5 m) being only found in the latter. Here we report on a new specimen (MPSC R 1221) composed of a partial right wing, which is the largest pterosaur discovered from the Crato Formation so far, having an estimated maximized wingspan of 5.5 m. Despite the incompleteness of this material, MPSC R 1221 can be referred to the Anhangueridae based on the length ratio between the metacarpal IV and the first wing phalanx. According to the osteohistological study and the degree of fusion, MPSC R 1221 represents a sub-adult individual, showing that the animal had not reached the maximum size before its death. The present study shows that large-sized pterosaurs were also present in the Crato Formation and that their rarity might be an artefact of preservation.