A new oospecies of Ovaloolithidae from the Nanling Basin, Anhui Province, China, and its palaeogeographic implications

Dinosaur egg localities from Anhui Province, China, are primarily restricted to Xiuning, Xuancheng, Qianshan and Hefei Basins. Here we describe one dinosaur egg and some eggshells from the Upper Cretaceous Xuannan Formation in the Xintang Village, Wuhu City, Anhui Province, which represent the first discovery in the Nanling Basin. The newly discovered egg is assigned to a new oospecies Ovaloolithus nanlingensis based on the spherical morphology, large size and eggshell thickness, wide radial microstructures in the cone layer and two broad stripes in the prismatic zone of columnar layer. Radial sections of Ovaloolithus nanlingensis comprise the lower cone layer and the upper columnar layer, which is divided into the inner prismatic and the outer umbrella-like eggshell units. The ratio of the inner prismatic zone to the outer umbrella-like zone in the columnar layer is 7:10 and two broad bands occur in the prismatic zone of the columnar layer. Ovaloolithidae is mainly distributed in Shandong, Henan, Guangdong, Jiangxi provinces, and Xinjiang Autonomous Region, China; East Gobi and South Gobi provinces, Mongolia; Batken Region, Kyrgyzstan; Utah and Wyoming, North America. Ovaloolithus nanlingensis represents the first record of Ovaloolithidae in Anhui Province, China, and expands the palaeogeographic distribution of ovaloolithid eggs worldwide.