www.paucarina.com - Tours in Iquitos and Loreto Region of Peru on Amazon River. We are located 100 m 300ft away from Amazon River Visit our website to see more high quality pictures from this iguana The two species of lizard within the genus Iguana possess a dewlap, a row of spines running down their back to their tail, and a third "eye" on their head. This eye is known as the parietal eye, visible as a pale scale on the top of the head. Behind their neck are small scales which resemble spikes, known as tuberculate scales. These scales may be a variety of colors and are not always visible from close distances. They have a large round scale on their cheek known as a subtympanic shield.