Reptile & Amphibian Forums

Hello everyone,
Has anyone ever noticed a little white dot on the top of their blue tongued skinks head? It's in the center of the diamond shaped scale a little bit behind their eyes. When I only had one, I thought it was just an artifact, but when I got a second skink who had it, I started to wonder what it was. I'm a zoology major and believe it to be the part of the pineal gland (which was verified by a prof). It's the "third eye". Helps regulate the daylight cycle, tells them when to get up and sit under the light (along with other senses of course). Just thought it was something interesting to share. If anyone has heard this before or has any comments, I would love to hear them.
Kate

Here's a short summary of the pineal gland as it relates to reptilians.

The pineal gland (epiphysis cerebri) and the closely associated parietal eye (parapineal) make up the pineal complex of reptiles. In crocodiles, the entire complex is completely absent, and only turtles and lizards possess the parietal or "third eye". When it is present, the pineal complex has an influential role in circadian rhythms. The reptile parietal eye is actually photoreceptive, and it consists of a cornea, a lens, photoreceptive cells, and a nerve tract that connects it to the ephysis cerebri. It is located within a the parietal foramen under a transparent scale (Reiter 1981). The pineal gland of the Western Fence Lizard - Sceloporus occidentalis - is located directly on top of the head. A small foramen can be seen in the skull where the pineal gland protrudes (Nir 1977). In the chelonians, lacertilians, and birds, modified photoreceptor cells have been described as "rudimentary photoreceptor cells." This third eye of reptiles and birds is unique for the fact it can register day/night cycles independent from the eyes. The lizard pineal organ, for example, shows spontaneous electrical activity which is inhibited by illumination of the organ (Knight 1971).
The third eye is absent from lizards found at lower latitudes and present in those from higher latitudes; thus the pineal complex of lizards has some role in reproductive success where there is great variation in day length (Reiter 1981).
Snakes lack the parietal eye, and their pineal gland has lost all photoreceptive properties, assuming a more mammalian-like secretory function (Reiter 1981).
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Edward
Carpe diem

Thanks for saying it so eloquently