Green Iguana Anatomy
The Green Iguanas Anatomy Explained
1. Tuberculate Scales
Tuberculate scales are small tubular spikes that protrude behind the tympanum, above the front limbs and can come in a variety of colors.
2. Tympanum (Ear)
Iguanas have good hearing and can pick up sounds best in the 500 - 3,000Hz range. 
The jowls are skin and muscle that seem to "hang" on either side of the head. Males have significantly large and more defined jowls than females do. The presence of enlarged jowls is used in Sexing Iguanas.
4. Subtympanic Shield
The subtympanic shield serves little purpose. It is possible its large size would help dissuade predators by fooling them into believing it is a large eye or it may help to break up the iguanas shape amongst the trees.
An iguanas dewlap is a flap of skin that serves several purposes which are discussed on our Iguana Body Language page.
The iguanas mouth is lined with small teeth designed to shred vegetation. These same teeth are capable of lacerating human flesh extensively. Damage caused by an iguana can be seen on our Iguana Body Language page.
The nostril of an iguana is used to breathe and expel excess salts as a result of their digestive process.
8. Rostral Horn
The rostral horn can appear alone or in a set of 2 or 3 and are not found on all iguanas. They can also be different sizes.
9. Eye Ridge
The protrusion, or "ridge" above the eye.
Iguanas have very keen eyesight and can see shapes, shadows, colors and movement at long distances.
11. Brain Bumps
The bumps on an iguanas head are not truly "brain bumps", they are actually fatty deposits that are a characteristic found in male iguanas.
12. Nuchal Crest
An ornamental projection of small spikes found on the back of the neck (nape), behind the fatty deposits.
13. Caudal Spines
These are the spines that run along the ridge of the back and tail. These spikes may serve more than the purpose of simply making the iguana an attractive species.
Learn more: Iguana Spikes Function
1. Femoral Pores
The femoral pores on the legs of iguanas are called femoral pores because they run along the femur bone of the upper thigh. Both sexes have femoral pores, but male pores are much more pronounced and secrete a waxlike substance during breeding season. This image is of a male iguanas femoral pores.
Femoral pores are a great indicator of the gender of your iguana once it has reached maturity.
Learn more: Sexing Iguanas
Iguanas do indeed have teeth. As the image shows, they have very sharp teeth designed to rip apart vegetation. These teeth are also capable of tearing flesh, which can be seen on our Iguana Body Language page.
1. Parietal Eye
The parietal eye, often called the third-eye, is photoreceptive and is used by the iguana to detect changing light patterns overhead. This ability allows them to detect predators (like birds) as they cast their shadow. Unlike a true eye, the parietal eye doesn't actually see shapes.
We have used 2 example images to display how the same anatomical feature can appear differently within the species.
Resources - References
1. Hatfield III, James W.. Green Iguana The Ultimate Owners Manual. Dunthorpe Press, 2000. (p.53)
2. Hatfield III, James W.. Green Iguana The Ultimate Owners Manual. Dunthorpe Press, 2000. (p.57)
3. Iguana head shot & femoral pores © Lacey LaDuke
4. Green Iguana in Chleby Zoo, Czech Republic. © Cheva, May 1 2009
5. Green Iguana Parietal Eye 1 © D.Walker
6. Green Iguana Parietal Eye 2 © Rob Hampshire