Iguana

Iguana
A green iguana (Iguana iguana)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Sauropsida
Order:	Squamata
Suborder:	Iguania
Family:	Iguanidae
Genus:	Iguana Laurenti, 1768
Species
Lesser Antillean Iguana, I. delicatissima Green Iguana, I. iguana

Iguana is a genus of lizard native to tropical areas of Central and South America and the Caribbean first described by Austrian naturalist Josephus Nicolaus Laurenti in his book Specimen Medicum, Exhibens Synopsin Reptilium Emendatam cum Experimentis circa Venena in 1768. The genus iguana includes two species: the Green Iguana and the Lesser Antillean Iguana.

The word "Iguana" is derived from a Spanish form of the original Taino name for the species "Iwana".

Physical Characteristics

Although all iguana species tend to look alike, they come in a wide variety of sizes, colors, and behaviors. An iguana looks like a very generic lizard, except for they all have a dewlap, spines going down their back to their tail, and a third eye on their head. This eye is known as the Parietal eye, which looks just like a pale scale on the top of their head. Behind their neck are small scales which look like little spikes--Those are known as Tuberculate Scales They also have a large round scale on their cheek called a Subtympanic Shield.

There are roughly 40 recorded species of iguana, of which 12 are endangered. The most common iguana is the Green Iguana, which lives high in the trees of jungles. However the Blue Iguana lives only on the island of Grand Cayman.

Sight

Iguanas have excellent vision and like humans they are very visually oriented creatures. They can see long distances, shapes, shadows, color and movement. An iguana uses its eyes to navigate through winding threes trees and confusing forests, as well as finding a nice leafy or fruity snack. They also use a lot of visual signals it interact with each other.

As mentioned above, iguanas have a Parietal eye on the top center of their head. This third eye is used to detect light and shadows. For example if a hungry bird is flying over head, the iguana will detect it's shadow and have a head start in front of the predator.

Hearing

An iguana's ear is known as the Tympanum. Basically it is the iguana's ear drum and it is located right above the Subtympanic Shield and behind the eye. This is a very thin, delicate part of the iguana, and crucial to its hearing.

Color

Like many animals, iguanas are very colorful. Obviously the Green Iguana is green and Blue Iguana is blue. Most iguana's colors come from where they live so they can blend in. In fact they can change their colors based on their surroundings. However placing a green iguana in a pink surrounding will not make it turn pink.

An iguana's colors are mostly a sign of health or emotion. If they turn really dark, with some blackish scales, that could either mean that the iguana is angry or that it is trying to get more sunlight. An orange or brown iguana means it is ill.