It is the namesake genus of the
Egernia genus-group, which also includes the
Solomon Islands skink (
Corucia),
Cyclodomorphus and the
blue-tongued skinks (
Tiliqua). In some older works, it is considered closely related to
Mabuya, but even among the
subfamily Lygosominae this genus does not seem to be particularly closely related and would—were the genus-groups treated at the rarely used rank of infrafamily—certainly constitute an infrafamily of its own. On the other hand, the enigmatic
crocodile skinks (
Tribolonotus) might be a very
basal member of the
Egernia genus-group. The genus
Egernia proper, as well as the other lineages, appear to be of
Miocene—probably
Early Miocene—origin, meaning they radiated at least 15, maybe 20 million years ago (mya). There are
fossils of
Egernia-like Lygosominae from around the
Oligocene-
Miocene boundary 23 mya, but these cannot be assigned to the present genus with certainty. Rather, they appear to be basal members of the
Egernia genus-group, still very
plesiomorphic Lygosominae with a
habitus similar to
Mabuya. ==Species==