Reassessment of an azhdarchid pterosaur specimen from the Mifune Group, Upper Cretaceous of Japan

The Japanese pterosaur record is relatively scarce and represented by a limited number of fragmentary specimens from Cretaceous deposits, including a partial cervical vertebra of an azhdarchid from the “Upper Formation” (Turonian-Coniacian) of the Mifune Group in Kumamoto Prefecture, on the island of Kyushu, Japan. Here, we redescribe this notable Japanese pterosaur specimen and test its phylogenetic position. We interpret it as a sixth cervical vertebra and identify diagnostic features that enable its recognition as a new taxon, Nipponopterus mifunensis gen. et sp. nov. It is noteworthy that this represents the first nominal species of pterosaur from Japan and that this new taxon shows numerous quetzalcoatline features, being strikingly similar to the unnamed Burkhant azhdarchid from the Turonian–Coniacian of Mongolia. Our phylogenetic analysis places Nipponopterus as a sister taxon to the Burkhant azhdarchid and nested within the clade of Quetzalcoatlinae.