Zhongjianornis an enlarged, keeled breastbone in more advanced birds. However, later analysis of the anatomy of "Z. yangi" cast doubt on this interpretation of the bird as very primitive. Research published in 2012 found that some of the apparently primitive features were due to poor preservation of the bones, and that "Zhongjianornis" is more similar in anatomy to primitive euornitheans like "Chaoyangia" and "Schizooura". A phylogenetic analysis showed that a very primitive position in the bird family tree for "Z. yangi" is unlikely given current evidence. Zhongjianornis Zhongjianornis is a genus of beaked, pigeon-sized birds from the early Cretaceous period of
Gray's Anatomy medicine; the anatomy of facial aging; and technical aspects and applications of diagnostic radiology. The senior editor of this book and accompanying website on ExpertConsult is Professor Susan Standring, who is Emeritus Professor of Anatomy at King's College London. The three most recent editions differ from all previous editions in an important aspect: they present anatomical structures by their regional anatomy (i.e. ordered according to what part of the body the structures are located in – e.g. the anatomy of the bones, blood vessels and nerves, etc. of the upper extremity is described in one place). All editions of "Gray's