First record of a complete giant theropod egg clutch from Upper Cretaceous deposits, South Korea

Abstract

Here, we report the first occurrence of a complete Macroelongatoolithus clutch from outside of China. Excavated from Upper Cretaceous strata of Aphae-do in Shinan-gun, Jeollanam-do Province, South Korea, the clutch of 19 eggs is characterised by large, elongate, symmetrical eggs arranged in a single-layered ring-shaped clutch. Eggs are inclined towards the centre of the 2.3-m diameter clutch, and average 41.17 cm long and 15.58 cm wide. Of the 19 eggs, 8 clearly retain a paired configuration. This specimen represents only the second report of large theropod eggs from South Korea and is the most complete Macroelongatoolithus clutch known from the region to date. Eggshell microstructural features are consistent with Macroelongatoolithus xixiaensis (oofamily Elongatoolithidae), previously known only from Cenomanian strata of southeastern China. This first record of a giant theropod egg clutch, here assigned to M. xixiaensis, extends the stratigraphic and paleogeographic range of Macroelongatoolithus eggs and parent animals to include the Campanian of South Korea.

Keywords::

• giant theropod clutch
• Aphae-do, Korea
• Upper Cretaceous
• Macroelongatoolithus xixiaensis
• Elongatoolithidae
• oviraptorid
• dinosaur eggs

Acknowledgements

The authors thank curator Jo Yong-jin of the Mokpo National History Museum, researcher Gwak Se-Keon and the students of the Korea Dinosaur Research Center for excavation, and Jeong Gyung-tak, Shin Hyang-a, Kim Jeong-mo and Joo Ri-ra for fossil preparation during the past 2 years. The authors also thank Professor Jin Xingsheng of the Zhejiang Museum of Natural History for access to eggshell samples for comparative study, Dave Varricchio and Daniel Barta for edits on drafts of this manuscript, and Frankie Jackson for valuable input and revision.

Additional information

Funding

Funding

This research was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF), funded by the Ministry of Education [grant number 2013R1A1A2061021], Mokpo City of Korea.