The word iguana is derived from a Spanish form of the Taíno name for the species: iwana. The species was first officially described by Swedish botanist Carl Linnaeus in 1758. The genus was first described in 1768 by Austrian naturalist Josephus Nicolaus Laurenti.
Paleontologists discovered the fossilized remains of two almost-complete skeletons of this extinct critter in a dinosaur nesting site in northwestern Montana.
The animal has been officially dubbed Magnuviator ovimonsensis, which translates roughly to “mighty traveler of Egg Mountain,” and experts say it is an extremely unusual find.
The newly discovered “mighty traveler of Egg Mountain” is an ancient lizard that lived 75 million years ago. That’s 10 million years before dinosaurs went extinct.
In 2015, Paleontologists from the University of Alberta found the lizard fossil, named Gueragama sulamericana, in the rocky outcrops of a Late Cretaceous desert, which is said to date back around 80 million years.
It is the first acrodontan lizard to be found in South America and shows that this group of lizards was more widely distributed on the supercontinent Pangaea, which formed about 270 million years ago and broke apart about 200 million years ago than previously thought.
It’s a missing link in the sense of the palaeobiogeography
“This fossil is an 80 million-year-old specimen of an acrodontan in the New World,” explains Dr. Caldwell.
“It’s a missing link in the sense of the palaeobiogeography and possibly the origins of the group, so it’s pretty good evidence to suggest that back in the lower part of the Cretaceous, the southern part of Pangaea was still a kind of single continental chunk.”
Distributions of plants and animals from the Late Cretaceous period reflect the ancestry of Pangaea when it was whole.
This is an Old World lizard in the New World at a time when we weren’t expecting to find it
“This Gueragama sulamericanafossil indicates that the group is old, that it’s probably southern Pangaean in its origin, and that after the break up, the acrodontans and chameleon group dominated in the Old World, and the iguanid side arose out of this acrodontan lineage that was left alone on South America,” says Dr Caldwell.
“South America remained isolated until about five million years ago. That’s when it bumps into North America, and we see this exchange of organisms north and south. It was kind of like a floating Noah’s Arc for a very long time, about 100 million years. This is an Old World lizard in the New World at a time when we weren’t expecting to find it. It answers a few questions about iguanid lizards and their origin.”
But lead author Tiago Simoes says the discovery also poses some questions that have yet to be considered.
“This finding raises a number of biogeographic and faunal turnover questions of great interest to both paleontologists and herpetologists that we hope to answer in the future.”
Dr. Caldwell says, having established that the group evolved much earlier than previously thought, they now need to look for even older rock formations to uncover further details of the evolutionary process.
What did the grape say when the Iguana stood on it?
Nothing, it just let out a little wine!
There are 350 species of iguanas living around the world today. Only 3 of these species are living and breeding here in Florida:
- Common Green Iguana
- Mexican Spinytail Iguana
- Black Spinytail Iguana
One of the most visually striking members of the Iguanidae family is the Grand Cayman iguana.
Also known as the blue iguana, this exquisite creature is one of the few naturally blue-hued animals in the world. It’s also the heaviest of all iguanas.
Iguanas are cold-blooded and thrive in hot climates. That’s why you’ll often see them basking in the warm sunlight.
Whenever the temperature drops below 40 degrees Fahrenheit, the lizards’ muscles essentially become paralyzed and they fall into a state of hibernation.
This doesn’t happen often in the hot tropics of Central America, but in places like southern Florida, where they’ve been introduced by humans, an unseasonable winter cold snap can literally cause scores of these scaled critters to lose their grip on tree limbs and fall to the ground.
During abnormally cold weather, iguanas are known to modify their behavior. They will burrow underground or hide in caverns and hollows in the heat reservoirs found there.
During this state, iguanas will appear rigid, their skin color darkened in a natural attempt to increase heat absorption.
If disturbed, the reptile will not rouse.
Their skin will feel cold to the touch and they will be unresponsive to pain. It can be difficult to determine if they are dead or alive!
While it’s quite an alarming sight to witness, the tumble doesn’t necessarily mean certain death.
The reptiles usually perk up again when the temperature rises.
How To Tell Male From Female?
Mature adult male iguanas tend to be noticeably larger than mature females. Males may have bumps on the top of their heads as well as longer spikes going down the length of their back.
Males are also more likely to have a large dewlap underneath their chin and large muscles next to their jaws. The muscles give the male iguanas the appearance of having swollen jowls. Male iguanas also have noticeable femoral pores on the insides of their legs.
Male green iguanas have a special flap of skin called the dewlap. This dewlap helps them to regulate their temperature. Male iguanas can raise their dewlap to appear bigger than they really are, either to intimidate predators or impressive females.
Female iguanas tend to have longer, slimmer bodies, smaller heads and do not have bumps on top of their heads. Female iguanas are the only ones who lay eggs. If you notice your iguana has laid eggs, then you can know with absolute certainty that you own a female iguana.
Your veterinarian can probe your iguana’s cloacal vent to determine whether your pet is a boy or a girl.
Your veterinarian will be the best person to accurately determine the gender of your iguana, especially if you own a young iguana. Juvenile iguanas are significantly more difficult to correctly sex.
If your iguana is less than a year old, a veterinarian will be the only person who can accurately find out your pet’s gender.
Iguana Breeding…
Female iguanas will develop eggs regardless of whether or not they have physically mated with a male. During the breeding season, your female may appear thin in the legs and tail with a bulging belly. The bulging belly is visible even with the fact female iguanas may be less likely to eat during the breeding season.
During breeding season you may also notice gender-specific behavior changes in your iguanas. Males are known to become significantly more aggressive, may behave in a territorial manner and even display physically threatening behaviors, including biting and attacking. Some males also turn an orange color during the breeding season.
The Tale Of An Iguana Tail…
Iguanas use their tail for balance while climbing and maneuvering. But these long appendages serve as self-defense.
When encountering a predator or other threat, the iguana will distract and bewilder its attacker by thrashing its tail. Sometimes the tail will break off and the creature is able to make a quick getaway. (Don’t worry, the tail grows back later.)
In the event that a predator tries to eat an iguana, its tail is equipped with spiky spinal combs that make it a difficult meal to swallow.
Why Are Iguanas So Colorful?
Iguanas are masters of camouflage, blending into their surroundings is their best form of protection from predators. One common question that iguana owners ask has to do with the color of their iguana. People wonder what is “normal” coloring and what is not. To make matters worse, various products in the pet stores claim to enhance your iguana’s coloring.
It is a common belief that green iguanas can change color as chameleons can. However, this is not accurate. Iguanas are capable of color changes, but only in specific situations. Some situations deal with stress, others with breeding issues, and some simply because the iguana is basking in the sun.
One of the most obvious color changes in the iguana is when it is taken outside for some real sunlight. Most iguanas immediately become dark. Their heads turn dark grey, almost black for some individuals, and the stripes on the iguana’s body become very apparent.
Many iguanas have brown marks that appear on their back that are never seen inside and give the iguana a sort of leopard-like markings. The reason they darken is that dark colors absorb more of the sun than light colors do. It’s like wearing a black t-shirt on a very hot day compared to wearing a white t-shirt. The white t-shirt reflects the light better, the black t-shirt absorbs it more. You also feel much hotter in the black t-shirt. When the iguanas start to feel too hot, they lighten up their coloration. This helps them thermoregulate when they are in the sun.
Stress can produce a colorful array of shades that you would never normally see on an iguana. Each iguana responds in its own way regarding color changes due to stress. Once the source of stress is gone the reptile slowly returns to its normal colors.
Iguanas Live 15 to 20 Years Or More!
Breeding season also produces many color changes in both male and female iguanas. The most notable one is the orange color that males develop as they enter their season. It generally starts on the legs, and the shade of orange can actually vary from a light orange to a very bright, almost neon orange. The color can also change on the sides of the iguana’s body, as well as the tail.
The coloration can last for a few months, as that is the normal length of iguana breeding season. Females may also develop some orange coloration, but rarely to the extent that males do. Generally, the color fades as the iguana’s breeding season ends, but some iguanas retain the coloration and always have some orange on them. This is more common in males.
The worst color change an iguana can have is when it is sick. They tend to be brownish in color, and show other signs of illness such as lethargy. Although orange hues are normal for some iguanas, they are sometimes a sign of severe dehydration or kidney disease. If orange coloring appears suddenly in an older iguana and is not associated with the breeding season, a veterinary visit is recommended.
Blue Iguanas are true beauties. Their blue color makes them stand out from distance. True Blue Iguanas (Axanthic Iguanas) have a gene needed to make a snow iguana (blizzard iguana).
According to the San Diego Zoo, Banded iguana skin is so photosensitive that any part of the skin in shade is a completely different color of green than the skin in sunlight.
Do iguanas have a third eye? Also known as a parietal eye, this organ is used to alert iguanas (as well as other reptiles) of aerial threats.
Unlike the lizard’s other two eyes, the parietal eye is quite simple in its physiology and can only detect changes in lightness and darkness. But that is more than enough to evade predators.
Iguana Diet
Owning a green iguana is far easier than the marine iguana of the Galapagos Islands. This lizard spends a great deal of time under the sea. The creature uses its excellent swimming skills to forage for red and green algae for its diet.
Green iguanas are herbivores which means that they eat plant matter. In the wild, iguanas eat leaves, flowers, and some fruits. Some species such as the spiny tail iguana are opportunistic eaters. Feeding on smaller animals, eggs, and arthropods. Juveniles tend to be insectivores, becoming more herbivorous as they get older.
Feeding your iguana a well-balanced diet of greens, vegetables, fruits, and some other foods will help ensure that you have a happy and healthy pet. Be sure to supply your pet with a variety of different foods. This helps make sure the diet is balanced and is a way for your pet to try different and interesting foods. Most of the foods needed are easy to get from pet stores and grocery stores.
Greens, Vegetables & Fruit
Fresh greens and vegetables should make up most of your pet’s diet. The food should be chopped up to make eating it easier. Some greens you could feed your pet include collard, mustard & dandelion greens, turnip greens, kale, and romaine lettuce. Vegetables your iguana may like are shredded carrots, peas, green beans & other beans, bell peppers, and squash.
Frozen vegetables can be substituted from time to time or when you have run out of fresh food. A mixture of french-cut green beans, peas, carrots, lima beans, and corn is good emergency food.
Make sure you warm the frozen veggies to room temperature before feeding them to your iguana. Running warm water over the frozen food is a quick way to thaw it.
Fruit can be added to an iguana’s diet for variety. Some fruits your pet may enjoy include strawberries, blueberries, bananas, apples, and cantaloupe. Like other foods, fruit should be chopped for easy eating.
Because iguanas are important seed dispersers for many native plants, their protection is vital to ecosystem health.
Iguana Food
There is commercial iguana food available that can make a nice addition to your pet’s diet.
Iguana food is usually in pellet form and can be mixed with other foods your pet eats. Since the pellets are dry, moistening them before feeding is a way to make them healthier. Iguana food should not be the primary diet of your iguana. We suggest Mazuri brand food.
Bread & Grains
Bread and grains can be occasionally added to your pet’s food. Cooked pasta, cooked rice, and whole grain bread make a nice treat for your iguana. Make sure the food is chopped for easy eating.
Insects
Crickets and mealworms are often a standard part of a pet reptile’s diet. This is not the case for green iguanas. They are herbivores and are not designed to eat insects.
Insects are a source of protein and adult iguanas do not need a lot of protein. What protein they need is gotten from greens and vegetables. Too much protein may actually be harmful to a pet iguana.
Water
An iguana will get a lot of his water from his food but still needs a source water. A heavy bowl, that is difficult to spill and filled with fresh water, should always be available.
Supplements
Reptile supplements help ensure a pet iguana gets all of his necessary vitamins and minerals.
A calcium & vitamin D3 supplements can be added to your pet’s food a couple times per week. A reptile multivitamin can be added to your pet’s food about once a week.
Supplements usually come in powder form and are easily sprinkled onto food. You only need to sprinkle a very small amount. Supplements should be added to your iguana’s food in moderation. Too much supplementation can be worse than none at all.
Click to go learn more about Plants that are NOT good for your animals
Housing Iggies…
Iguanas can be some of the most difficult herps to house correctly. They are frequently kept in enclosures that are entirely too small, and they have very specific habitat needs that are often not met.
An Iguana’s health is very dependent on the quality of its housing. The information below will help you to set up the perfect habitat, before bringing your iguana home, to make sure he lives a long, happy, and healthy life.
If you have been looking in pet stores for an iguana terrarium, you may as well stop now. The majority of commercially made cages are either too tall and narrow or too long and short. They aren’t appropriate housing for an arboreal reptile that likes to stretch out to his full length high in the enclosure. The best cages are those that you make yourself or have custom-made for you.
When considering cage size, it’s vital that you know how large your iguana is going to grow. Green Iguanas can reach a length of five to six feet in just four to five years, a fact that many people don’t realize when looking at tiny little hatchlings. Your iguana should be able to stretch out to his full length in any part of the temperature gradient throughout the cage, and this is impossible with a small cage. The minimum cage size should be:
- Width:1-1/2 to 2 times the iguana’s full length
- Height: 1 to 1-1/2 times the iguana’s full length
- Depth: 1/2 to 1 times the iguana’s full length
Materials you can use to make your enclosure include wood, glass, Plexiglas, hardware cloth, and plastic coated wire mesh. Never use glass or Plexiglas if you plan on putting the cage in direct sunlight, as they do not provide proper air circulation and temperatures will be too high.
The enclosure should have a tight-fitting lid to prevent escape and smooth sides to prevent injury to your iguana’s feet, nose, and tail. If you are using wood, be sure to seal it with a waterproofing agent and caulk all of the joints to ensure that you can properly clean the cage. In warm areas of the country, you may want to build a walkout enclosure to allow your iguana access to the outdoors.
Placement of the Enclosure Place your Green Iguana’s enclosure somewhere that is quiet, but where he will still have interaction with people. The room you choose should be dim or dark after sunset to provide the proper photoperiods.
Iguana Species
GALÁPAGOS MARINE IGUANAS
- Amblyrhynchus cristatus albemarlensis ~ Isabela Marine Iguanas
- Amblyrhynchus cristatus cristatus ~ Fernandina Marine Iguanas
- Amblyrhynchus cristatus hassi ~ Santa Cruz Marine Iguanas
- Amblyrhynchus cristatus mertensi ~ San Cristóbal Marine Iguanas
- Amblyrhynchus cristatus nanus ~ Genovesa Marine Iguanas
- Amblyrhynchus cristatus sielmanni ~ Pinta Marine Iguana
- Amblyrhynchus cristatus venustissimus ~ Española Marine Iguanas
FIJI IGUANAS
- Brachylophus bulabula ~ Central Fijian Banded Iguanas
- Brachylophus fasciatus ~ Lau Banded Iguanas
- Brachylophus vitiensis ~ Fijian Crested Iguanas
GALÁPAGOS LAND IGUANAS
- Conolophus marthae ~ Pink Land Iguanas
- Conolophus pallidus ~Barrington Land Iguanas
- Conolophus subcristatus ~ Galápagos Land Iguanas
SPINY-TAILED IGUANAS
- Ctenosaura acanthura ~ Veracruz Spiny-tailed Iguanas
- Ctenosaura alfredschmidti ~ Campeche Spiny-tailed Iguanas
- Ctenosaura bakeri ~ Útila Spiny-tailed Iguanas
- Ctenosaura clarki ~ Balsas Spiny-tailed Iguanas
- Ctenosaura conspicuosa ~ San Esteban Spiny-tailed Iguanas
- Ctenosaura defensor ~ Yucatán Spiny-tailed Iguanas
- Ctenosaura flavidorsalis ~ Yellow-backed Spiny-tailed Iguanas
- Ctenosaura hemilopha ~ Baja California Spiny-tailed Iguanas
- Ctenosaura macrolopha ~ Sonoran Spiny-tailed Iguanas
- Ctenosaura melanosterna ~ Black-chested Spiny-tailed Iguanas
- Ctenosaura nolascensis ~ Nolasco Spiny-tailed Iguanas
- Ctenosaura oaxacana ~ Oaxaca Spiny-tailed Iguanas
- Ctenosaura oedirhina ~ Roatán Spiny-tailed Iguanas
- Ctenosaura palearis ~ Motagua Spiny-tailed Iguanas
- Ctenosaura pectinata ~ Guerreran Spiny-tailed Iguanas
- Ctenosaura praeocularis ~ Southern Honduran Spiny-tailed Iguanas
- Ctenosaura quinquecarinata ~ Five-keeled Spiny-tailed Iguanas
- Ctenosaura similis similis ~ Common Spiny-tailed Iguanas
- Ctenosaura similis multipunctata ~ Providence Spiny-tailed Iguanas
ROCK IGUANAS
- Cyclura carinata ~ Turks and Caicos Rock Iguanas
- Cyclura collei ~ Jamaican Rock Iguanas
- Cyclura cornuta ~ Hispaniolan Rhinoceros Iguanas
- Cyclura cychlura cychlura ~ Andros Rock Iguanas
- Cyclura cychlura figginsi ~ Exuma Rock Iguanas
- Cyclura cychlura inornata ~ Allen Cays Rock Iguanas
- Cyclura lewisi ~ Grand Cayman Blue Rock Iguanas
- Cyclura nubila caymanensis ~ Sister Islands Rock Iguanas
- Cyclura nubila nubila ~ Cuban Rock Iguanas
- Cyclura onchiopsis (extinct) ~ Navassa Rhinoceros Iguanas
- Cyclura pinguis ~ Anegada Rock Iguanas
- Cyclura ricordii ~ Ricord’s Rock Iguanas
- Cyclura rileyi cristata ~ Sandy Cay Rock Iguanas
- Cyclura rileyi nuchalis ~ Acklins Rock Iguanas
- Cyclura rileyi rileyi ~ San Salvador Rock Iguanas
- Cyclura stejnegeri ~ Mona Rhinoceros Iguanas
DESERT IGUANAS
- Dipsosaurus catalinensis ~ Santa Catalina Desert Iguanas
- Dipsosaurus dorsalis dorsalis ~ Western Desert Iguanas
- Dipsosaurus dorsalis sonoriensis ~ Sonoran Desert Iguanas
GREEN IGUANAS
- Iguana delicatissima ~ Lesser Antillean Iguanas
- Iguana iguana ~ Common Green Iguanas
CHUCKWALLAS
- Sauromalus ater (synonym obesus) ~ Common Chuckwallas
- Sauromalus hispidus ~ Spiny Chuckwallas
- Sauromalus klauberi ~ Catalina Chuckwallas
- Sauromalus slevini ~ Slevin’s Chuckwallas
- Sauromalus varius ~ Piebald Chuckwallas
