they were convinced that there truly did exist something between their eyes, called a pineal gland, though its usefulness had not yet been discovered by scientists.
In humans, it's buried in the center of the brain. It secretes melatonin. That's it. It can calcify and interfere with sleep as a person ages.
In tuataras, since it's closer to the skin, it senses light and shadow. And secretes melatonin.
