EPOW - Ecology Picture of the Week

A Snake-eyed Skink

Swanson's Snake-eyed Skink (Cryptoblepharus cygnatus), Family Scincidae
Northern Territory, Australia

Explanation:  This week we are staying in the Northern Territory of Australia, where last week we visited a spiraled denizen of the mangroves.  Now, still in the mangroves, we have encountered a curiously-named snake-eyed skink.

More specifically, this is Swanson's snake-eyed skink, which is fully endemic to the Northern Territory of Australia, found nowhere else.  

This skink is mostly arboreal, but I found it here climbing an outside wall of a building, also one of its commonly-used habitats.

Although it has a narrow distribution, it is listed as Least Concern by IUCN because it is locally abundant.  

 

 

However, a study (Horner 2007) suggests that this species might actually constitute two "sibling" species that are identical in appearance except for some differences in the underside of the feet!  

So why is this species, and others of this genus Cryptoblepharus (and also the genus Ablepharus, for that matter), called snake-eyed?  It is because these species lack eyelids, and instead the eye is covered with a transparent scale, called a spectacle, which is similar to the anatomy found in snakes.

As to how this evolved in snake-eyed skinks, and why not in other skinks or in other lizards, is as yet unanswered.  

  

Information:
    Horner, P.  2007.  Systematics of the snake-eyed skink genus Cryptoblepharus.  Records of the Museums and Art Galleries of the Northern Territory, Darwin, NT, Australia