State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing, 100083, China.
School of the Earth Sciences and Resources, China University of Geosciences, Beijing, 100083, China.
BMC Ecol Evol. 2022 May 9;22(1):60. doi: 10.1186/s12862-022-02012-x.
Dinosaur eggs containing embryos are rare, limiting our understanding of dinosaur development. Recently, a clutch of subspherical dinosaur eggs was discovered while blasting for a construction project in the Upper Cretaceous red beds (Hekou Formation) of the Ganzhou Basin, Jiangxi Province, China. At least two of the eggs contain identifiable hadrosauroid embryos, described here for the first time.
The eggs, attributable to Spheroolithidae indet., are thin-walled and small (~ 660 mL) compared to those of Lambeosaurinae. The shape of the embryonic squamosal is reminiscent of that seen in the Late Cretaceous hadrosauroids Levnesovia transoxiana, Tanius sinensis, and Nanningosaurus dashiensis, suggestive of possible affinities.
The small size of the eggs and embryos, similar to those of Hadrosaurinae, indicates that the larger eggs and hatchlings typical of Lambeosaurinae are evolutionarily derived.
含有胚胎的恐龙蛋十分罕见，这限制了我们对恐龙发育的理解。最近，在中国江西省赣州盆地白垩纪红层（河口组）的一个建筑项目爆破过程中，发现了一窝球形恐龙蛋。至少有两个蛋含有可识别的鸭嘴龙胚胎，这是首次对此进行描述。
这些蛋壳属于 Spheroolithidae 未定种，与 Lambeosaurinae 的蛋相比，蛋壳较薄且较小（~660 毫升）。胚胎鳞状骨的形状让人联想到晚白垩世的鸭嘴龙类 Levnesovia transoxiana、Tanius sinensis 和 Nanningosaurus dashiensis，表明可能存在亲缘关系。
蛋和胚胎的小尺寸与鸭嘴龙类相似，表明更大的蛋壳和幼体是 Lambeosaurinae 进化而来的衍生特征。
