A new scincid lizard from the Miocene of northern Australia, and the evolutionary history of social skinks (Scincidae: Egerniinae)

A new species of fossil lizard, Egernia gillespieae, has been identified from the mid-Miocene AL90 site in Australia's Riversleigh World Heritage Area. This discovery provides the first detailed morphological description of an articulated fossil skink, offering crucial insights into the evolutionary history of social skinks (Scincidae: Egerniinae). By integrating morphological and molecular data, researchers determined that the modern Australian radiation of egerniines began at the end of the Eocene (34.1 million years ago), with E. gillespieae closely related to living Egernia species. Additionally, another fossil, previously classified as 'Tiliqua' pusilla, was found to occupy a basal position within the clade that includes modern genera like Tiliqua and Cyclodomorphus. These findings highlight the significant evolutionary diversification of social skinks by the mid-Miocene, providing calibration points for their radiation timeline.

Thorn, K. M., Hutchinson, M. N., Archer, M., & Lee, M. S. Y. (2019). A new scincid lizard from the Miocene of northern Australia, and the evolutionary history of social skinks (Scincidae: Egerniinae). Journal of Vertebrate Paleontology, 39(1), e1577873. https://doi.org/10.1080/02724634.2019.1577873