The southern grass skink (Pseudemoia entrecasteauxii) is a species of lizard in the family Scincidae. The species is endemicto Australia, where it is found in the south-east of the continent, as well as in Tasmania and the islands of Bass Strait. Although it occurs in a variety of habitats, it is most commonly found in open grassy woodlands.[3][4]
The Southern grass skink has a lifespan of about 5 or 6 years. It grows up to 7.5 cm (3.0 in) in length (not including the tail). Male skinks change colouration during the breeding season.
The southern grass skink has become a model species for reproductive biology in reptiles because it gives birth to live youngand exhibits non-invasive epitheliochorial placentation. Unlike the majority of live bearing reptiles, Pseudemoia develop complex placentae, which provide a substantial amount of nutrients to the embryo through pregnancy.[6] Pregnancy in squamates is supported by the evolution of a novel state of gene regulation.[7] The amount of nutrients provided is dependent on the amount of food females consume during pregnancy, and, unlike other live-bearing reptiles, scarcity of food during pregnancy can cause developmental failure. Together, these results suggest that placental nutrient transport may only be a successful mode of reproduction if food is abundant throughout pregnancy, which may limit its opportunities to evolve in some reptiles.[8] Lipid transport in this species most likely occurs through the yolk sac placenta and is facilitated in part by the production of the protein lipoprotein lipase.[9] The extra-uterine embryo did not invade maternal tissue, suggesting fundamental differences between the nature and evolution of placentation in southern grass skinks and eutherian mammals.
https://en.wikipedia.org/wiki/Pseudemoia_entrecasteauxii
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