2025-11-11 ニューサウスウェールズ大学（UNSW）
Artistic reconstruction of a female mekosuchine nesting in the swampy environments of the Murgon fossil site. Also shown is one of the abundant giant soft-shell turtles, Murgonomys braithwaitei, an archaic marsupial, Djarthia murgonensis, and an unnamed ancestral song-bird. The clays that form the fossil deposit were accumulated in this ancient lake.Image: Panades et al 2025 (generated with Gemini AI)
＜関連情報＞
- https://www.unsw.edu.au/newsroom/news/2025/11/scientists-unearth-australias-ancient-drop-crocs
- https://www.tandfonline.com/doi/full/10.1080/02724634.2025.2560010
オーストラリア最古のワニの卵殻：メコスチヌスの生殖古生態に関する知見 Australia’s oldest crocodylian eggshell: insights into the reproductive paleoecology of mekosuchines
Xavier Panadès I Blas,Àngel Galobart,Michael Archer,Michael Stein,Suzanne Hand & Albert Sellés
Journal of Vertebrate Paleontology Published:11 Nov 2025
DOI:https://doi.org/10.1080/02724634.2025.2560010
ABSTRACT
Alongside large madtsoiid snakes, the largest known lizards, thylacoleonid marsupials and a range of other terrestrial carnivores, the now extinct mekosuchine crocodylians were significant predators during most of the Cenozoic in Australia. Although the skeletal fossil record for mekosuchines extends from the lower Eocene through the Quaternary, fossil evidence relating to their reproductive biology (e.g., eggshells, eggs, clutches, or nests) has been reported but not studied. Here, we describe Australia’s oldest crocodylian eggshell from the purple layer of the lower Eocene Tingamarra Local Fauna of the Oakdale Sandstone of Murgon, south-eastern Queensland, Australia. The eggshells belong to a new crocodylian eggshell type which differs structurally from all other crocodylomorph eggshells. Given the abundance in the Tingamarra deposits of specimens representing two mekosuchine crocodylians, both referable to species of Kambara and with no other crocodylians being present in this deposit, it is parsimonious to presume that these eggshells were produced by one or both of these mekosuchine species. A preliminary taphonomic analysis of the oological remains sheds light on aspects of the reproductive behavior of these mekosuchines.
