Postcranial anatomy of <i>Dsungaripterus weii</i> (Pterosauria: Ornithocheiroidea) from the Lower Cretaceous of Wuerho, China

Ornithocheiroidea was a globally diverse group of pterosaurs during the Cretaceous. However, well-documented ornithocheiroids are highly derived, hampering our understanding on the morphological evolution of this clade. <i>Dsungaripterus weii</i> Young, 1964 from the Lower Cretaceous Tugulu Group (Valanginian) of the Junggar Basin is an iconic early member of Ornithocheiroidea. <i>Dsungaripterus</i> is known from numerous three-dimensionally preserved specimens, ranging from isolated bones to partially articulated individuals. Here we provide a comprehensive description of the postcranium of <i>Dsungaripterus</i>. We find that <i>Dsungaripterus</i> has many autapomorphies in the postcranial skeleton parallelling its unique skull, including the asynchronous fusion between the sacrum and pelvis and a posterodorsal fossa of the humerus with a paper-thin bone wall. <i>Dsungaripterus</i> also displays some plesiomorphic features of Ornithoecheiroidea, for example, limb bones with relatively thick bone walls, variably reduced pneumatic features in cervical vertebrae and appendicular skeletons, absence of spinoprezygapophyseal and spinopostzygapophyseal ridges in middle-series cervical vertebrae, at least one metacarpal articulating with the distal syncarpal, and a distally displaced adductor ridge on the femur. Additionally, <i>Dsungaripterus</i> possesses some unexpected features possibly convergent with other members of Ornithocheiroidea. Although the postcranial skeletons of <i>Dsungaripterus</i> are represented by osteologically mature specimens, notable morphological variation is present. Functional reconstructions of several aspects of the postcranial skeleton of <i>Dsungaripterus</i> are elucidated, including the arrangement of the metacarpophalangeal region during terrestrial locomotion. Niche partitioning between the two dsungaripterids from the Tugulu Group of Wuerho, <i>Dsungaripterus</i> and <i>Noripterus</i>, is supported by their distinct dentitions, neck morphology, and limb proportions.