Like some other living vertebrates, including some lizards, the tuatara has a third eye on the top of its head called the parietal eye (also called a pineal or third eye) formed by the parapineal organ, with an accompanying opening in the skull roof called the pineal or parietal foramen, enclosed by the parietal bones. [63]

A parietal eye (third eye, pineal eye) is a part of the epithalamus in some vertebrates. The eye is at the top of the head; is photoreceptive; and is associated with the pineal gland, which regulates circadian rhythmicity and hormone production for thermoregulation. [1]

An example of one of these archaic traits is its third eye. Today, the tuatara only has two visually functional eyes – what an underachiever. These eyes are impressive in their own right, though, with highly adapted night vision and the ability to focus independently of one another.

Tuatara really do have a third eye in the middle of the forehead. It’s called the parietal eye (pronounced pa-rye-e-tal) (1). So why can’t we see this eye? It turns out the parietal eye is covered from birth by a layer of translucent skin, plus possibly some small scales.

2024年12月3日 · Sitting on the top of its head, the tuatara has a third eye complete with retina, lens, and nerve endings that connect to its brain. Scientists previously thought the eye was used to watch out for predators above, but we’ve since learned that the …

2025年2月21日 · Tuatara also have a third, or parietal, eye on the top of the head. Although this eye has a rudimentary lens, it is not an organ of vision. It is thought to serve an endocrine function by registering the dark-light cycle for hormone regulation. Tuatara display no ear openings.

2014年12月11日 · As a refresher from our earlier discussions here on WEIT, the ancestors of tuatara and lizards did not have a “normal”, functional third eye in the middle of their heads. Read the captions in the photos above for more details on the external appearance of the eye.

Parietal eye (third eye) After four to six months, it becomes covered with opaque scales and pigment. It likely serves to regulate the circadian rhythm and possibly detect seasonal changes, and help with thermoregulation. Of all extant tetrapods, the …

2017年12月3日 · Tuatara were named by the Māori for the spiny ‘peaks’ that run along their backs, but perhaps their most intriguing feature is the third eye that sits on the top their head. This eye is known as a parietal eye – it’s far more primitive than a regular eye, but it still has a lens and a retina, and is photosensitive, meaning it can sense ...

2017年5月11日 · The tuatara is often referred to as having a third eye because of a light-sensitive organ on the top of its head, similar to the ones found in many lizards. Ancient isolation