The alpine cool-skink (Carinascincus greeni), also known commonly as the northern snow skink, is a species of lizard in the family Scincidae. It is endemic to Tasmania, Australia where it mainly occurs within the north of the state.
The specific name, greeni, is in honor of Tasmanian ornithologist Robert "Bob" Green.
This species was previously known as Niveoscincus greeni, however has since been reclassified as Carinascincus, along with several other species within the Niveoscincus genus.
Carinascincus greeni is an alpine skink which has small dark scales with pale green to bronze coloured spots. The head is sometimes paler than the body, with larger spots. C. greeni has been found to grow up to 95mm in length, with midbody scales in 39-44 rows around the body.
Carinascincus greeni is skink species endemic to alpine areas of Tasmania above 1000 meters of elevation. They are mostly observed around Cradle Mountain and the central plateau, however they are found as far east as Ben Lomond National Park and as far south as Mt Field.
They are restricted to rocky banks of streams and swamps, as well as boulder fields where they can often be found basking. Where they co-occur with other species within the same genus such as Carinascincus microlepidotus, C. greeni has been found to competitively exclude them from the optimal basking spots of exposed rocks and boulders.
Carinascincus. greeni has adapted to the cooler climate of high altitudes by evolving viviparity, retaining their eggs during the gestation process and giving birth to live young. Retaining their eggs during gestation is what has allowed C. greeni to protect their eggs from the rapid changes in temperature they would otherwise be exposed to in the alpine environments they inhabit. This skink species gives birth to a litter of 2-4 young around March, and only reproduces biannually; females can store sperm over the winter and fertilize their eggs during spring.
Carinascincus greeni is listed as vulnerable under the IUCN Red List, with the main threat being climate change, which is likely to reduce the extent of cool habitats the species relies on. In addition, climate change may cause lowland skink species such as Carinascincus metallicus and Carinascincus ocellatus to encroach on the limited habitat that C. greeni occupies. This threat is compounded by the fact that these lowland species reproduce annually instead of biannually like C. greeni.