The absence of the prefrontal bone and the non-diapsid skull allows Yanornis to be classified as an ornithuromorph, a member of a group of stem-birds which also includes the common ancestor of living birds.
Similarly, its scapula and coracoid had evolved the basic shape and layout as in modern birds, enabling Yanornis to lift its wings far above its back for an efficient upstroke.
[9] The order Yanornithiformes has been erected to mark their distinctness from other early Ornithurae such as Gansus, but might be called Songlingornithiformes; especially if the present taxon is indeed a junior synonym of Songlingornis as sometimes proposed.
[10] Archaeorhynchus spathula Jianchangornis microdonta Chaoyangia beishanensis Schizooura lii Vorona berivotrensis Zhongjianornis yangi Patagopteryx deferrariisi Hongshanornis longicresta Longicrusavis houi Yixianornis grabaui Hollanda luceria Songlingornis linghensis Yanornis martini Gansus yumenensis Ambiortus dementjevi Apsaravis ukhaana Ornithurae The genus name Yanornis is derived from the Ancient Chinese Yan dynasties, whose capital was at Chaoyang, and Ancient Greek ornis, "bird".
[1] Some studies have found that the bird species Aberratiodontus wui is in fact a poorly preserved specimen of Yanornis martini, or at least a close relative,[11][12] an opinion which has been supported by subsequent reviews of enantiornithine taxonomy.