China's Jurassic fossil discovery sheds light on bird origins

The researchers used several methods to explore the position of Baminornis zhenghensis in the evolutionary tree of birds. The results showed that Baminornis zhenghensis was only just derived than Archaeopteryx and it represents one of the oldest birds.

"If we take a step back, and reconsider the phylogenetic uncertainty of Archaeopteryx, we do not doubt that Baminornis zhenghensis is the true Jurassic bird," said Zhou Zhonghe from the Institute of Vertebrate Paleontology and Paleoanthropology of the Chinese Academy of Sciences, co-author of the study.

The second fossil is incomplete, consisting solely of a furcula. The researchers performed geometric morphometric and phylogenetic analyses to explore its relationship with other non-avialan and avialan theropods. Interestingly, the results supported the referral of this furcula to Ornithuromorpha, a diverse group of Cretaceous birds. Given its poor preservation, however, the team refrained from naming a new taxon based on this single bone, and its placement within birds needs further fossil evidence.

The research publication also reported a 150-million-year-old avialan theropod from the same locality of Baminornis zhenghensis. Taken together, these new fossils are a tour de force, suggesting an earlier origin of birds and a radiation of early birds in the Jurassic era, according to the researchers.