Restudy On Sapeornithids Form The Lower Cretaceous Of Yixian County, Liaoning

Western Liaoning has been one of the classic areas for studying the late Mesozoic strata and the Jehol Biota for over eighty years. Since 1990s, with the discoveries of abundant rare fossils such as Confuciusornis sanctus, Sinosauropteryx prima, Eomaia scansoria and Archaefructus liaoningensis, western Liaoning has become the most famous area for the study of Mesozoic strata, the origin and evolution of primitive birds, primitive mammals and early angiosperms in China and even all over the world. The Jehol Biota can be compared to the biota from Solnhofen, Bavaria of Germany in the richness, diversity and preservation of fossils. Fossil birds in the Jehol Biota are very rich. Up to now, 25 genera and 31 species have been reported, including Avialae, Pygostylia, Ornithurae and Enantiornithes. The discovery and study of these fossils not only fill the gap of the record of Mesozoic birds, but also have great value on the study of the phylogeny, behavior, living environment and other aspects of Mesozoic birds. In addition, it also provides very important information for the study of the origin, evolution and interrelationship of primitive birds. This paper deals with three specimens of pygostylian birds, which were collected from the Jiufotang Formation of Early Cretaceous in Baitaigou area, Yixian County, Jinzhou City of Liaoning Province, China. According to our current study, the specimens CAGS-03-07-08 and JZPM-LSV-130 are assigned to Sapeornis chaoyangensis and the specimen CDPC-02-08-001 is considered to be a new taxon, Didactylornis jii gen.et sp. nov. Based on their shared characters, a family, Sapeornithidae is newly erected herein. Phylogenetic analysis is carried out by using...