A new oospecies of Shixingoolithus (Shixingoolithus qianshanensis oosp. nov.) from the Qianshan Basin, Anhui Province, East China

Here we describe two newly discovered dinosaur eggs from the Upper Cretaceous Chishan Formation in the Qianshan Basin, Anhui Province, East China. These dinosaur eggs can be assigned to a new oospecies of Stalicoolithidae, Shixingoolithus qianshanensis, based on the following combined features: the larger size of eggs, the uniform eggshell microstructure in the radial section, the smaller height and the larger density of radial microstructures at the inner surface of the eggshell. Radial sections of S. qianshanensis show closely arranged columnar eggshell units forming relatively uniform and dense microstructure; some secondary eggshell units and numerous sub-circular radial microstructures appear separately in the middle and inner parts of the tangential sections, respectively. The discovery of S. qianshanensis provides new fossil types of Stalicoolithidae and represents the first dinosaur relative record in the Qianshan Basin, which offer accurate paleontological evidence of Late Cretaceous–Early Paleocene stratigraphic classification in the Qianshan Basin, Anhui Province.