• anatomy;
  • Aptian;
  • Changma Basin;
  • diversity;
  • Early Cretaceous;
  • Enantiornithes;
  • evolution;
  • phylogeny;
  • Qiliania graffini gen. et sp . nov.;
  • Xiagou Formation

In recent years, the Lower Cretaceous (Aptian) Xiagou Formation has yielded approximately 100 avian partial skeletons, many with soft-tissue traces, from sites in the Changma Basin of Gansu Province, north-western China. The most abundant taxon amongst these is the ornithuromorph Gansus yumenensis, but enantiornithines have also been identified in the sample. Here we describe two incomplete, semi-articulated appendicular skeletons, the first consisting of a partial left pelvic girdle and complete pelvic limb, and the second comprised of a nearly complete right pelvic limb. Both specimens bear characteristics diagnostic of Enantiornithes, and are referred to a new taxon, Qiliania graffinigen. et sp. nov. The exceptional, three-dimensional preservation of these specimens (compared to the crushed, nearly two-dimensional condition of most other Early Cretaceous avian fossils) reveals new information regarding enantiornithine anatomy, evolution, and diversity.

© 2011 The Linnean Society of London, Zoological Journal of the Linnean Society, 2011, 162, 201–219.