While a recent discovery may change textbooks and the way that many scientists think about bird and dinosaur evolution, it comes as no surprise us.
This week, Xing Xu, H. You, K. Du and F. Han published in the journal Nature a reanalysis of early bird evolution. The analysis knocks Archaeopteryx off its perch as a grandfather to later birds.
KU has been the central hub for the discovery of the fossil bird beds in the Early Cretaceous of China with the description of the primitive bird, Confuciusornis, and has continued to be involved with all the new discoveries coming out of this region in part through an alumnus of the KU vertebrate paleontology program.
The alumnus, Zhonghe Zhou, presently leads Chinese studies in that region and was recently elected to the prestigious National Academy of Sciences. Zhou and one of the paper’s authors, Xing Xu, had already precipitated a revolution in our understanding of bird evolution with the discovery of the four-winged gliding bird/dinosaur, Microraptor. With Microraptor, they showed that bird flight began with gliding.
Zhou has a long-term collaboration with KU vertebrate paleontology researchers at the Biodiversity Institute. Preparator David Burnham, collection manager Desui Miao and I regularly visit China to work on early birds. Our research also has suggested that Archaeopteryx along with other archaic birds represents a side branch that split off much earlier than the new bird, Xiaotingia, and its sister Anchiornis, another four-winged gliding animal.
While the recent paper in Nature calls these animals “feathered dinosaurs,” we think that they and their common ancestor with modern birds can be best considered true birds. Rather than removing Archaeopteryx from Aves because its avian features were shared with birdlike dinosaurs, we place a stronger emphasis on these features thereby pulling the dinosaur-like birds into Aves. This limits these flying, feathered animals to the Class Aves and pushes the origin of birds into the Early Jurassic or Late Triassic at about the same time as the dinosaurs themselves.