Dinosaur eggs and nests from Jaeun Island, Shinan, South Korea = 신안군 자은도에서 발견된 공룡알과 둥지 화석 연구

다국어 초록 (Multilingual Abstract)

About twenty-one dinosaur eggs, including at least four nests, were discovered on Jaeun Island, South Korea, and identified as Propagoolithus oosp., a member of the Faveoloolithidae oofamily. These eggs were found in a reddish sandy mudstone from Jaeundo Tuff, and they are characterized by the subspherical morphology, a multicanaliculate pore system with filispherulitic morphotype, and distinct pore apertures on the outer surface. Based on age dating results (84-82 Ma) in this area, it is concluded that these eggs were laid by titanosaurian dinosaurs, a sauropod group that only survived globally until the Late Cretaceous, including the Korean Peninsula. The shape of the egg nest consists of a linear and grouped arrangement of eggs, showing a convex bowl-shaped structure. This form of the nest is interpreted as a structure formed by burrowing into the ground by Titanosauria to lay eggs. Also, tiny fragments between sediments were observed inside intact eggs. It indicates that they have undergone a hatching process underground, like some turtle nests. Additionally, the hatching windows in the upper part of the eggs and the resorption crater-like structures developed at the bottom of the eggshell indicate the possibility that the eggs have been fossilized after successful hatching.

목차 (Table of Contents)

• Content
• List of figures · ⅲ
• Abstract · ⅶ
• 1. Introduction 1
• 1.1 Background 1
• 1.2 Previous studies of dinosaur eggs from South Korea · 2
• 2. Geological Setting 9
• 2.1 Cretaceous deposits of the Korean Peninsula 9
• 2.2 Geological setting of study area 11
• 3. Materials and Methods 15
• 3.1 Classification of dinosaur eggs 15
• 3.2 Materials 29
• 3.3 Methods · 30
• 4. Description 32
• 4.1 Occurrences 32
• 4.2 Morphology of the nest and eggs · 40
• 4.3 Structural features of dinosaur eggs 44
• 5. Discussion · 51
• 5.1 Classification of the dinosaur eggs 51
• 5.2 Estimation of the egg producer · 56
• 5.3 Nest construction and nesting behavior 59
• 5.4 Possibility of hatching 62
• 6. Conclusions 68
• References 70
• Abstract in Korean · 79