New enantiornithine bird reveals the refinement for cranial kinesis occurring early in avian evolution
Enantiornithes is the most diverse Mesozoic birds. Approximately half of the known global diversity of Enantiornithes is from the Early Cretaceous Jehol Biota of China. The Jehol birds are usually complete and articulated, but compressed in two dimensions. Consequently, key features regarding some skeletal elements, particularly the gracile skull bones, are obscured by crushed and overlying elements. Thus, detailed cranial morphology remains largely unknown for enantiornithines. In a paper published online August 21 in Journal of Systematic Palaeontology, Dr. WANG Min, Institute of Vertebrate Paleontology and Paleoanthropology (IVPP), Chinese Academy of Sciences, and his colleagues reported a new enantiornithine bird from the Early Cretaceous Jehol Biota. Although incomplete, the skeleton is disarticulated and several cranial elements are exquisitely well preserved in their entirety, providing morphological information that had previously been poorly understood.