In a paper published online October 29 in the journal of Chinese Science Bulletin (CSB), a team of young researchers from the Institute of Vertebrate Paleontology and Paleoanthropology of the Chinese Academy of Sciences (IVPP) described a new species of bird from the new Sihedang locality of the Yixian Formation, part of the Jehol Group exposed in northeastern China. The newly discovered locality has yielded a large number of birds, all referable to a single taxon, which the team named Iteravis huchzermeyeri, suggesting that the success of the enantiornithines in the Cretaceous may not have necessarily been as pervasive as previously inferred.
The new species’ binomial (meaning Huchzermeyer’s journey bird in Latin) is in honor of the late South African biologist, Dr. Fritz Huchzermeyer, in recognition of his scientific journey, which throughout his life led him through numerous fields of study, including paleontology. In the last two years of his life Dr. Huchzermeyer participated in two important papers with IVPP scientists, one published in Nature (Zheng et al., 2013) and the other in PlosONE (Zheng et al., 2014). Dr. Huchzermeyer provided invaluable knowledge and quickly developed a deep camaraderie with IVPP colleagues – his indomitable spirit and expertise will be deeply missed and the team hopes to honor his passing with the naming of this species. His life long quest for knowledge sets the bar to which all scientists should aspire. He is remembered by friends and colleagues alike and lives on through his three children and five grandchildren.
This new bird, like Dr. Huchzermeyer, is interesting on many levels, contributing several important pieces of information: first, it represents the most derived ornithuromorph so far collected from the Jehol Group, although the specimen comes from the lowest geologic level to preserve this clade (128 Ma Yixian Formation). Ornithuromorpha is the clade of birds that includes Neornithes, which in turn includes all living birds. This specimen is more closely related to the derived Late Cretaceous Ichthyornis than any other Jehol bird, revealing derived features appeared early than thought.
Second, the Sihedang locality is entirely dominated by Iteravis, similar to the Changma locality of the Xiagou Formation that is dominated by the ornithuromorph bird, Gansus. Most other Jehol localities are dominated by the Enantiornithes, the supposed first avian radiation and dominant clade of Cretaceous land birds. Notably, Iteravis and Gansus are morphologically similar, which suggests they share a specific aquatic habitat that was captured by the Changma and Sihedang localities. Alternatively, the large number of specimens of a single taxon may suggest some form of social gathering, such as lekking males or a breeding colony. In any case, the discovery of an ornithuromorph dominated locality 128 million years ago indicates that broad evolutionary hypotheses regarding the rise and fall of Enantiornithes and the rise of Ornithuromorpha need to be re-evaluated in light of potential sampling and preservational biases. The Gansus dominated Changma locality was thought to represent the beginning of the faunal shift between Enantiornithes and Ornithuromorpha, which ends with the former clade going extinct at the end Cretaceous. However, the discovery of an ornithuromorph dominated locality at the earliest horizon to preserve this clade indicates either enantiornithines were not truly dominant or that dominance must be re-evaluated in light of potential behavioral and ecological factors.
Lastly, the new specimen preserves a previously undocumented tail morphology that appears to be comprised of two short feathers – if correct this represents the first recognized Early Cretaceous ornamental tail morphology. All other Jehol ornithuromorphs clearly preserve aerodynamic tail morphologies. Confuciusornis and enantiornithines have paired ornamental tail feathers but these differ in they are much longer and thus would have incurred more drag than the short feathers in Iteravis.
This work was supported by the National Basic Research Program of China, and the National Natural Science Foundation of China. 
Fig.1 Holotype specimen of Iteravis huchzermeyeri (IVPP V18958) (Image by Jingmai Kathleen O'Connor) 
Fig.2 Dr. Fritz Huchzermeyer (12 January 1930 – 3 March 2014), a prominent South African biologist.
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