A probable ornithopod egg from a historic collection of dinosaur eggs recovered from the Upper Cretaceous of Liaoning Province, China

ABSTRACT

Since the first discovery of dinosaur eggs announced by the American Museum of Natural History (central Asiatic expeditions to Mongolia) in 1923, these fossils became widely recognised from Mesozoic strata in Asia and elsewhere. In the 1920s, and actually before 1923, dinosaur eggs had been collected from another part of Asia, specifically Liaoning Province in northeastern China. From 1921 to the late 1920s, five eggs were collected from the Cenomanian Quantou Formation during construction, and thus represent an important historic collection as some of the earliest dinosaur eggs discovered in Asia. Here, we describe one egg from this collection and assign it to Paraspheroolithus irenensis, an egg taxon that likely belonged to hadrosaur dinosaurs. The egg is approximately 7 × 8 cm in diameter, with eggshell that displays typical spheroolithid microstructure and is just over a millimetre in thickness. Paraspheroolithus irenensis is shown to be the most widespread spheroolithid oospecies in China, and our comparative work extends its geographic range to northeastern most China. The Quantou Formation thus has yielded at least three spheroolithid oospecies, indicating the potential for a diversity of hadrosaur or related ornithopod species in the region at that time.

KEYWORDS:

• China
• dinosaur egg
• Late Cretaceous
• Liaoning Province
• Quantou Formation
• Spheroolithidae

Acknowledgments

We are grateful to staffs at the Dalian Natural History Museum, Natsuko Takagi at Nagoya University Museum, and Kosuke Nakamura at Hokkaido University for technical support. We also appreciate Dr Daniel Barta and two anonymous reviewers for their constructive comments and suggestions.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the Japan Society for the Promotion of Science [JP19K23453] to KT and a Natural Sciences and Engineering Research Council of Canada Discovery Grant [RGPIN04854] to DKZ.