An egg clutch of the Stalicoolithidae discovered in Wuning, Jiangxi, China

doi:10.19615/j.cnki.2096-9899.230519

Abstract

Abstract:

Here we describe an incomplete dinosaur clutch with three broken eggs and seven prints discovered in Wuning County, Jiangxi Province, that can be referred to Coralloidoolithus shizuiwanensis based on the following features: the eggs are nearly spheroid and arranged tightly and irregularly in the clutch, the eggshell thickness ranges 2.76-2.97 mm, the horizontal accretion lines are almost evenly distributed throughout the eggshell, and the secondary eggshell units are distributed in the medial and outer zones of the columnar layer. This egg clutch of Coralloidoolithus shizuiwanensis represents the first discovery of dinosaur eggs in Wuning County, and shows the age of the strata containing the dinosaur eggs in this area should be Late Cretaceous.

Key words: Wuning County, Jiangxi Province, Late Cretaceous, dinosaur eggs, Stalicoolithidae

摘要：

记述了江西省武宁县发现的一恐龙蛋不完整蛋窝。基于以下特征将这一新发现归入石嘴湾珊瑚蛋(Coralloidoolithus shizuiwanensis ): 恐龙蛋化石近球形，在蛋窝中紧密不规则分布，蛋壳厚度2.76-2.97 mm; 水平生长线均匀分布于整个蛋壳，柱状层中段和外段发育大量次生壳单元。这一蛋窝代表了武宁县恐龙蛋化石的首次发现，也说明该区域产恐龙蛋地层时代应该为晚白垩世。

关键词: 江西武宁, 晚白垩世, 恐龙蛋, 石笋蛋类

CLC Number:

Q915.2

ZHOU Ming-Xiao, YAN Yun, QIU Wen-Jiang, FANG Kai-Yong, ZHU Xu-Feng, WANG Qiang, WANG Xiao-Lin. An egg clutch of the Stalicoolithidae discovered in Wuning, Jiangxi, China. Vertebrata Palasiatica, 2023, 61(4): 317-325.

周明笑, 严允, 邱文江, 方开永, 朱旭峰, 王强, 汪筱林. 2023, 61(4): 317-325, 江西武宁石笋蛋类恐龙蛋蛋窝的发现. 古脊椎动物学报.

Figures/Tables 4

Fig. 1 The incomplete clutch of Coralloidoolithus shizuiwanensis (WNCM-V1) from Wuning, Jiangxi A. three broken eggs (No. 2, 3, 5) and seven prints with a few eggshell remnants, eggs were arranged tightly and irregularly; B-D. magnification figures of the egg No. 2 (B), No. 3 (C) and No. 5 (D)

Fig. 2 Microstructure of the Coralloidoolithus shizuiwanensis in radial section (S221008-1②) under ordinary light (A) and cross-polarized light (B) White lines show the boundaries between the inner, medial and outer zones A. the boundary between the cone layer and columnar layer (red line) is not clear, accretion lines distribute through the shell, pore canals (black arrows) are irregular and worm-like, and the secondary eggshell units (white arrows) grow in the medial zone and the outer zone; B. the eggshell units show radial extinction through the nucleation centers (red arrows) to the outer surface, and secondary eggshell units (white arrows) show independent radial extinction

Fig. 3 Microstructure of the Coralloidoolithus shizuiwanensis in radial section A. the accretion lines are concentric arcs around the nucleation centers (red arrow); B. the inner zone, light-colored stripes intersperse in accretion lines; C-F. the medial zone, accretion lines inside the light-colored stripes are blurred, conical (C, D) and fan-shaped (E, F) secondary eggshell units distributed; G-J. the outer zone, some secondary eggshell units are columnar-shaped and show narrow extinction under cross-polarized light (G, H), while the others are circular in shape and show petal-like extinction under cross-polarized light (I, J).A, C-H. S221008-1②; B, I, J. S221008-1①

Fig. 4 Microstructure of the Coralloidoolithus shizuiwanensis in tangential section A. section through the cone layer, red arrows point to radial microstructure surrounding the nucleation centers, pores are irregular in shape and vary in size; B. the inner zone, pores turn into more regular, most are nearly round; C. the medial zone, pores are nearly round, sickle-shape or nearly closed (black arrow); D. lower part in the outer zone, more pores are closed or nearly closed (black arrows) A, B. S221008-2①; C. S221008-2②; D. S221008-2③

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