What is White dorsal crests of a tuatara?

The white dorsal crests of a tuatara are prominent, spiny structures that run along the animal's back and are particularly noticeable in males. These crests are made up of modified scales and can play a role in thermoregulation, as well as display during mating rituals. The tuatara, a unique reptile native to New Zealand, is often referred to as a "living fossil" due to its ancient lineage and distinct morphology. The crests can become more pronounced during breeding season, serving as visual cues to potential mates.