New information on postcranial skeleton of the Early Cretaceous Gansus yumenensis (Aves: Ornithuromorpha)

Abstract

Gansus yumenensis Hou and Liu, 1984 is a basal ornithuromorph bird that has been recovered from the Lower Cretaceous Xiagou Formation in the Changma Basin of Gansu Province in northwestern China. Although it bears important significance in understanding the origin and early evolution of Ornithuromorpha, this taxon has only received preliminary morphological study. Here, we provide a detailed description of the postcranial morphology of Gansus yumenensis based on seven new specimens and new data from previously reported specimens, and update diagnosis for this taxon. Our phylogenetic analysis including new morphological data on Gansusyumenensis resolves all known four genera of Changma ornithuromorphs as more derived taxa than Jehol members of this clade, indicating the difference between Changma and Jehol avifauna.

Keywords::

• Gansus yumenensis
• Changma
• Xiagou Formation
• Early Cretaceous
• Ornithuromorpha
• anatomy
• phylogeny

Acknowledgements

We would like to thank the personnel of the former Fossil Research and Development Center, Third Geology and Mineral Resources Exploration Academy, and Gansu Provincial Bureau of Geo-Exploration and Mineral Development (Lanzhou, China) for discovering and preparing the specimens. We also thank Dr. Gareth Dyke for handling this manuscript, and Dr. Min Wang and two anonymous reviewers for their comments that improved the manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplemental data

The revised character states for Gansus yumenensis used in the phylogenetic analysis in this study can be accessed here: http://dx.doi.org/10.1080/08912963.2015.1006217.

Additional information

Funding

Funding was provided by the Hundred Talents Project of the Chinese Academy of Sciences, the National Natural Science Foundation of China [41472020, 40672007], the National Basic Research Program of China (973 Program) [2012CB821906] and the Bureau of Land and Resources of Gansu Province.