2025/09/01 by X Panades I Blas, Ãngel Galobart, Michael Archer +3 · 2 voices
Earth and Planetary Sciences · Environmental Science · #Paleontology and Evolutionary Biology #Evolution and Paleontology Studies #Amphibian and Reptile Biology
paper · doi:10.1080/02724634.2025.2560010
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.