On the phylogenetic affinities of the tapejarid pterosaur ‘Tupuxuara deliradamus’ from the Lower Cretaceous of Brazil

Abstract

ABSTRACT ‘Tupuxuara deliradamus’ was originally described as a tapejarid pterosaur from the Lower Cretaceous Romualdo Formation (Albian) of the Araripe Basin, Northeastern Brazil, and was regarded later by other authors as an indeterminate azhdarchoid. Whereas its taxonomic status remains controversial, its phylogenetic affinities were never investigated under computational analyses. Moreover, after its original description, other putative coeval pterosaurs have been described from Brazil. In the present study, these data are combined and we reconstruct the phylogenetic affinities of ‘Tu. deliradamus’ for the first time. It is recovered within Tapejarinae, nesting as the sister taxon to Caupedactylus ybaka. This result challenges the former assignation to Thalassodrominae. The holotype of ‘Tu. deliradamus’ shares a suit of traits of tapejarines, such as the lacrimal process of jugal being posteriorly inclined, the posterodorsal margin of the nasoantorbital fenestra forming an abrupt bend level with the dorsal margin of the orbit, and inclination of the quadrate with relation to the jugal bar is approximately 150°. Unfortunately, the fragmentary condition of SMKN PAL 6410 hampers a reliable taxonomic assignment at species level. Nevertheless, the new data supports its assignation to Tapejarinae indet.