Hadrosauroid eggshells from Cretaceous of China + dating dinosaur eggs
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Ben Creisler
Nov 10, 2025, 11:12:18 AM (yesterday) Nov 10
to DinosaurMa...@googlegroups.com
Ben Creisler
New papers:
Wenjiang Qiu, Hantang Hua, Kui Zhao, Han Yao, Fenglu Han & Rui Wu (2025)
The first discovery of Stromatoolithus pinglingensis in the Ganzhou Basin and a revision of Paraspheroolithus porcarboris
Historical Biology (advance online publication)
doi: https://doi.org/10.1080/08912963.2025.2581783
https://www.tandfonline.com/doi/full/10.1080/08912963.2025.2581783
In this study, we first report eggshell fragments of Stromatoolithus pinglingensis from the Upper Cretaceous Tangbian Formation in the Ganzhou Basin. These eggshells are characterised by a strongly sculptured outer surface, highly fused spherulitic shell units, well-developed accretion lines, and oval to round pores through tangential sections. Additionally, the ootaxon Paraspheroolithus porcarboris from the Upper Cretaceous ‘Argiles et Grès à Reptiles’ Formation of France, initially attributed to Spheroolithidae, has also been re-evaluated. P. porcarboris exhibits diagnostic features consistent with Stromatoolithus from the Laiyang (Shandong), Nanxiong (Guangdong), Shanyang (Shaanxi), and the Ganzhou (Jiangxi) basins in terms of external ornamentation and pore canal system. Consequently, we propose the reassignment of P. porcarboris as a new oospecies of Stromatoolithus: Stromatoolithus porcarboris. It represents both the first record of this ootaxon and thus the first evidence of hadrosaurid eggs in France. Notably, Stromatoolithus exhibits a distinct temporal restriction, exclusively documented in the latest Late Cretaceous (late Campanian to late Maastrichtian). The discovery of S. pinglingensis from both the lower (Ganxian District) and mid-upper (Nankang District) parts of the Tangbian Formation further provides the chronostratigraphic constraints for this formation in the Ganzhou Basin. It provides additional biostratigraphic evidence for the temporal distribution of vertebrate assemblages in the Ganzhou Basin. Furthermore, the co-occurrence of diverse hadrosaurid skeletal elements, embryonic eggs, and eggshell fragments offers valuable materials for the biogeographic distribution, phylogenetic relationships, community succession, and reproductive biology among Late Cretaceous hadrosauroids in southern China.
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Ryan T. Tucker, Kira E. Venter, Cristiano Lana, Eric M. Roberts, Tsogtbaatar Chinzorig, Khishigjav Tsogtbaatar & Lindsay E. Zanno (2025)
U-Pb calcite age dating of fossil eggshell as an accurate deep time geochronometer
Communications Earth & Environment 6: 872
doi: https://doi.org/10.1038/s43247-025-02895-w
https://www.nature.com/articles/s43247-025-02895-w
Earth’s sedimentary rock record is the primary archive for biotic, environmental, and climatic trends in deep time. Reconstructing these patterns requires a high-resolution geochronologic framework. This remains a significant challenge for many terrestrial ecosystems and an acute problem for some of the world’s most important Mesozoic and Cenozoic fossil records. Overcoming this issue requires frontier approaches, such as directly dating fossils, long considered untenable. Here, we test the reliability of novel LA-ICP-MS U-Pb calcite dating and elemental mapping of non-avian dinosaur eggshells to produce accurate “burial ages.” We directly dated fossilized dinosaur eggs recovered from the Western Interior Basin of North America, producing ages within 5% of high-precision ages from bracketing ash beds. We then directly dated dinosaur eggs from Upper Cretaceous strata within Mongolia’s famous yet poorly age-constrained Gobi Basin, providing the first radioisotopic age for these deposits. Geochemical data coupled with trace elemental mapping indicate early uptake of uranium (U) in non-avian dinosaur eggshells via sediment contact, consistent with findings from Quaternary avian eggs. Calcified eggs, having evolved over 250 million years ago, offers a promising experimental methodology for determining the age of globally distributed fossil assemblages and recovering temporal, environmental, and ecological data from a single fossil.
The first discovery of Stromatoolithus pinglingensis in the Ganzhou Basin and a revision of Paraspheroolithus porcarboris
Historical Biology (advance online publication)
doi: https://doi.org/10.1080/08912963.2025.2581783
https://www.tandfonline.com/doi/full/10.1080/08912963.2025.2581783
In this study, we first report eggshell fragments of Stromatoolithus pinglingensis from the Upper Cretaceous Tangbian Formation in the Ganzhou Basin. These eggshells are characterised by a strongly sculptured outer surface, highly fused spherulitic shell units, well-developed accretion lines, and oval to round pores through tangential sections. Additionally, the ootaxon Paraspheroolithus porcarboris from the Upper Cretaceous ‘Argiles et Grès à Reptiles’ Formation of France, initially attributed to Spheroolithidae, has also been re-evaluated. P. porcarboris exhibits diagnostic features consistent with Stromatoolithus from the Laiyang (Shandong), Nanxiong (Guangdong), Shanyang (Shaanxi), and the Ganzhou (Jiangxi) basins in terms of external ornamentation and pore canal system. Consequently, we propose the reassignment of P. porcarboris as a new oospecies of Stromatoolithus: Stromatoolithus porcarboris. It represents both the first record of this ootaxon and thus the first evidence of hadrosaurid eggs in France. Notably, Stromatoolithus exhibits a distinct temporal restriction, exclusively documented in the latest Late Cretaceous (late Campanian to late Maastrichtian). The discovery of S. pinglingensis from both the lower (Ganxian District) and mid-upper (Nankang District) parts of the Tangbian Formation further provides the chronostratigraphic constraints for this formation in the Ganzhou Basin. It provides additional biostratigraphic evidence for the temporal distribution of vertebrate assemblages in the Ganzhou Basin. Furthermore, the co-occurrence of diverse hadrosaurid skeletal elements, embryonic eggs, and eggshell fragments offers valuable materials for the biogeographic distribution, phylogenetic relationships, community succession, and reproductive biology among Late Cretaceous hadrosauroids in southern China.
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Free pdf:
Ryan T. Tucker, Kira E. Venter, Cristiano Lana, Eric M. Roberts, Tsogtbaatar Chinzorig, Khishigjav Tsogtbaatar & Lindsay E. Zanno (2025)
U-Pb calcite age dating of fossil eggshell as an accurate deep time geochronometer
Communications Earth & Environment 6: 872
doi: https://doi.org/10.1038/s43247-025-02895-w
https://www.nature.com/articles/s43247-025-02895-w
Earth’s sedimentary rock record is the primary archive for biotic, environmental, and climatic trends in deep time. Reconstructing these patterns requires a high-resolution geochronologic framework. This remains a significant challenge for many terrestrial ecosystems and an acute problem for some of the world’s most important Mesozoic and Cenozoic fossil records. Overcoming this issue requires frontier approaches, such as directly dating fossils, long considered untenable. Here, we test the reliability of novel LA-ICP-MS U-Pb calcite dating and elemental mapping of non-avian dinosaur eggshells to produce accurate “burial ages.” We directly dated fossilized dinosaur eggs recovered from the Western Interior Basin of North America, producing ages within 5% of high-precision ages from bracketing ash beds. We then directly dated dinosaur eggs from Upper Cretaceous strata within Mongolia’s famous yet poorly age-constrained Gobi Basin, providing the first radioisotopic age for these deposits. Geochemical data coupled with trace elemental mapping indicate early uptake of uranium (U) in non-avian dinosaur eggshells via sediment contact, consistent with findings from Quaternary avian eggs. Calcified eggs, having evolved over 250 million years ago, offers a promising experimental methodology for determining the age of globally distributed fossil assemblages and recovering temporal, environmental, and ecological data from a single fossil.
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