A new species of Jeholornis with complete caudal integument

Abstract

The Early Cretaceous long bony-tailed bird Jeholornis prima displays characters both more basal than Archaeopteryx and more derived, exemplifying the mosaic distribution of advanced avian features that characterises early avian evolution and obfuscates attempts to understand early bird relationships. The current diversity of Jeholornithiformes is controversial, since multiple possibly synonymous genera were named simultaneously. Here, we provide the first definitive evidence of a second species belonging to this clade, and erect the new taxon J. palmapenis sp. nov. This new specimen reveals the tail integument of Jeholornithiformes, the morphology of which appears to have no aerodynamic benefit suggesting this clade evolved plumage patterns that were primarily for display.

Keywords:

• Jeholornis
• feathers
• rectrix
• long-tailed birds
• Jehol Group

Acknowledgements

We thank Gao Wei for photographing the specimen and the National Natural Science Foundation of China (40121202), the Fellowship for Young International Scientists (2010Y1ZB1), Chinese Academy of Sciences and the Research Fund for International Young Scientists, from the National Natural Science Foundation of China (41050110438) for funding for this project.