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 Gray's Anatomy Gray's Anatomy is an English language textbook of human anatomy originally written by Henry Gray and illustrated by Henry Vandyke Carter. Earlier editions were called Anatomy: Descriptive and Surgical and Gray's Anatomy: Descriptive and Applied, but the book's name is commonly shortened to, and later editions are titled, "Gray's Anatomy". The book is widely regarded as an extremely influential work on the subject, and has continued to be revised and republished from its initial publication in 1858 to the present day. The latest edition of the book, the 41st, was published in September 2015. The English anatomist Henry