Lizards are a widespread group of squamate (scaled) reptiles, with over 6,000 species, ranging across all continents except Antarctica, as well as most oceanic island chains. Lizards range in size from chameleons and geckos a few centimeters long to the 3 meter long Komodo dragon.

The earliest known fossil remains of a lizard belong to the iguanian species Tikiguania estesi, dating to the Carnian stage of the Triassic period, about 220 million years ago.

The Jamaican iguana is the largest native land animal in Jamaica, and is critically endangered, even considered extinct between 1948 and 1990. Once found throughout Jamaica and on the offshore islets Great Goat Island and Little Goat Island, it is now confined to the forests of the Hellshire Hills.

Jamaican Iguana at Zoo Atlanta, Nov 2018, by Paul Sager, on Flickr


Most lizards are quadrupedal, four-footed and using all four feet for walking and running. Others are legless, and have long snake-like bodies. Lizards make use of a variety of anti-predator adaptations, including venom, camouflage, reflex bleeding, and the ability to sacrifice and regrow their tails.

The Fiji banded iguana is endemic to some of the southeastern Fijian islands. It is also found in Tonga, where it was probably introduced by humans. It is one of the few species of iguanas found outside of the New World and one of the most geographically isolated members of the family Iguanidae.

Fiji Banded Iguana at Zoo Atlanta, Nov 2018


Iguana is a genus of herbivorous lizards that are native to tropical areas of Mexico, Central America, South America, and the Caribbean. The genus was first described in 1768 by Austrian naturalist Josephus Nicolaus Laurenti. To acquire, process and digest plant matter, herbivorous lizards have developed a higher bite force relative to their size in comparison to carnivorous or omnivorous reptiles.

The preferred habitat for the blue iguana is rocky, sunlit, open areas in dry forests or near the shore, as the females must dig holes in the sand to lay eggs in June and July.

Grand Cayman blue iguana at Milwaukee County Zoo, Dec 2018


Most lizard species are harmless to humans. Only the largest lizard species, the Komodo dragon, which reaches 11 feet (3.3 meter) in length and weighs up to 366 lbs (166 kg), has been known to stalk, attack, and, on occasion, kill humans.

The Komodo dragon, also known as the Komodo monitor, is a species of lizard found in the Indonesian islands. Their unusually large size has been attributed to island gigantism, since no other carnivorous animals fill the niche on the islands where they live.

Komodo Dragon at Jacksonville Zoo, Nov 2018


Reptiles evolved about 320 million years ago, in the steaming swamps of the late Carboniferous period. The animals most closely related to modern reptiles were relively small until the extinction event known as Carboniferous Rainforest Collapse (CRC), about 305 million years ago. Reptiles have amniote eggs that have a membrane ensuring gas exchange out of water. Reptiles acquired new niches faster than amphibians in the drier climate that developed after the CRC event. They also acquired new feeding strategies, including plants and other animals where previously early reptiles feed only on insects and small fish. Reptiles continued to prosper and increase in number and variety leading to the Age of the Dinosaurs, from about 250- to 65-million years ago.

The northern caiman lizard is found in northern South America. The caiman lizard has heavily muscular jaws to help aid in eating its normal prey of snails, crawfish and fresh water clams. It has a long and flattened tail, similar to its namesake, the caiman. The long tail helps the caiman lizard to successfully swim and dive.

Caiman Lizard at Jacksonville Zoo, Nov 2018


Reptiles are tetrapod vertebrates, creatures that either have four limbs or, like snakes, are descended from four-limbed ancestors. Unlike amphibians, reptiles do not have an aquatic larval stage. Most reptiles are oviparous, animals that lay their eggs with little or no other embryonic development within the mother.

The brown anole is a lizard native to Cuba and the Bahamas. It has been widely introduced elsewhere, by being sold as a pet lizard. This species is highly invasive and outcompetes and consumes many species of native lizards.

Brown Anole at Washington Oaks Gardens State Park, Florida, Nov 2018


Reptiles are tetrapod animals in the class Reptilia, comprising today's turtles, crocodilians, snakes, amphisbaenians, lizards, tuatara, and their extinct relatives. Some reptiles are more closely related to birds than they are to other reptiles, for example: crocodiles are an example with the closer relation to birds rather than lizards. For this reason, many modern scientists prefer to consider the birds part of Reptilia as well.

Monitor lizards have long necks, powerful tails and claws, and well-developed limbs. They are almost entirely carnivorous. Deer make up about 50% of the diet of adults of the largest species, the Komodo Dragon. Although normally solitary, groups as large as 25 individual monitor lizards are common in ecosystems that have limited water resources.

Komodo Dragon at Cincinnati Zoo, July 2014


The images shared in this post come from several zoos, both EOS and Sony bodies and all Canon lenses. All images were captured in RAW and processed using Adobe Lightroom and Topaz DeNoise v6.

As the blue iguana consumes a variety of plant material, favoring fruits and flowers over leaves and stems when available, it is valuable on Grand Cayman as a seed disperser throughout its range. In late 2012, the Blue Iguana Recovery Program estimated that the wild population had risen to approximately 750 individuals, and the species has been downlisted from critically endangered to endangered.

Blue Iguana at Indianapolis Zoo, Dec 2014


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A splendid show of lizards and fascinating narrative. One of my favorite exhibits at John Ball Zoo in Grand Rapids was the Komodo dragon. He died a few years ago and I miss him. Your post was one of the best I've seen , Paul.