2025-06-03 中国科学院(CAS)
マニラプトル類の卵殻では、SEUが徐々に減少しています。カメ類、ワニ類、鳥盤類、竜脚類、獣脚類の恐竜のSEUは、平行進化(A)の結果である可能性もあれば、深い相同性(B)を持つ可能性もあります。(画像提供:IVPP)
<関連情報>
- https://english.cas.cn/newsroom/research_news/earth/202505/t20250529_1044691.shtml
- https://www.science.org/doi/10.1126/sciadv.adt1879
恐竜の卵殻に含まれる二次卵殻ユニットの生物起源がマニラプトラ類恐竜の失われたバイオミネラリゼーションプロセスを解明する Biogenic origin of secondary eggshell units in dinosaur eggshells elucidates lost biomineralization process in maniraptoran dinosaurs
Shukang Zhang, Seung Choi, Noe-Heon Kim, Junfang Xie, […] , and Albert G. Sellés
Science Advances Published:30 May 2025
DOI:https://doi.org/10.1126/sciadv.adt1879
Abstract
Secondary eggshell units, though rarely observed in modern avian eggshells, are marked structures in non-avian dinosaur eggshells that offer valuable paleobiological insights. Despite their significance, the origins of secondary eggshell units remain understudied, leading to debates in paleontology, including the hypothesis of an abiogenic origin for these structures. Here, we demonstrate that secondary eggshell units in non-avian dinosaur eggshells are biogenic in nature, based on analyses using advanced microscopic techniques. The structural characteristics of these units suggest a formation mechanism similar to that of turtle and crocodile eggshells, with matrix fibers likely initiating their development. Furthermore, a diminishing presence of secondary eggshell units in non-avian maniraptoran dinosaurs points to the evolution of a more refined physiological process for eggshell formation in this lineage. These findings shed light on the evolutionary trajectory of eggshell biomineralization in dinosaurs and their close relatives.
