Reappraisal of Mythunga camara Molnar & Thulborn, 2007 (Pterosauria, Pterodactyloidea, Anhangueria) from the upper Albian Toolebuc Formation of Queensland, Australia

Abstract

Mythunga camara, the most complete pterosaur described from Australia, derives from the Lower Cretaceous (Albian) Toolebuc Formation of central Queensland, Australia. Although it was originally described as an archaeopterodactyloid, more recently Mythunga has been designated as an indeterminate anhanguerid or ornithocheiroid. The holotype specimen is a partial skull, comprising a fragment of the premaxilla, incomplete maxillae and dentaries, and an isolated cranial element preserved in matrix within the nasoantorbital fenestra. Reassessment of the holotype specimen has revealed several new features, which enable a re-evaluation of the phylogenetic position of this taxon. Primary among these observations is that the anteriormost preserved teeth are, in fact, the root of a maxillary tooth and its replacement, rather than a pair of contralateral teeth; thus, they do not represent the anteriormost tooth pair as previously proposed. Redescription of the holotype specimen has also resulted in the identification of several previously unrecognised features, including several nutrient foramina on the maxilla and mandible and shallow channels on the maxilla. Furthermore, the bone lodged within the nasoantorbital fenestra is identified herein as the right splenial. Following the redescription and reinterpretation of the holotype specimen, the phylogenetic position of Mythunga camara was assessed. Although this analysis placed Mythunga within the Anhangueria, most of this clade was reduced to a polytomy; only the clades representing Anhanguera and Boreopterinae + Guidraco were resolved. The classification of Mythunga within Anhangueria indicates that this clade was widespread, and perhaps achieved a global distribution by the late Early Cretaceous.