2025/11/09 by Wenjiang Qiu, Hantang Hua, Kai Zhao +3 · 1 voice
Materials Science · Earth and Planetary Sciences · #Diatoms and Algae Research #Paleontology and Stratigraphy of Fossils #Geology and Paleoclimatology Research
paper · doi:10.1080/08912963.2025.2581783
openalex publication_date 2025/11/09 · openalex created_date 2025/11/10 · openalex updated_date 2026/07/21
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.