Kevin Schafer / Galapagos Marine Iguana (Amblyrhynchus cristatus) with Lava Lizard (Trpoidurus) on head. Fernandina island, Galapagos.

Andrew Cooper / Marine Iguana (Amblyrhynchus cristatus) on rocks with wave splash. Galapagos, Ecuador.

Roland Seitre / Grand Cayman Blue Iguana (Cyclura lewisi), adult that has been reintroduced to the wild from captive breeding programme. Endangered species.

Tui De Roy / Marine iguana (Amblyrhynchus cristatus) males migrating to breeding areas at the onset of warm season. Galapagos Islands, Ecuador, December.

Tui De Roy / Marine iguanas (Amblyrhynchus cristatus) sky-pointing position to keep cool in sun. Punta Espinosa, Fernandina Island, Galapagos Islands, Ecuador, June.

Tui De Roy / Marine iguana (Amblyrhynchus cristatus) in profile against dark background. Galapagos Islands, Ecuador, December.

Tui De Roy / Marine iguana (Amblyrhynchus cristatus) in cloud of flies. Galapagos Islands, Ecuador, June.

Tui De Roy / Marine iguana (Amblyrhynchus cristatus) emerging from sea onto beach, with Sally lightfoot crabs (Grasopus graspus) and Galapagos Fur Seal in background. Galapagos Islands, Ecuador, June.

Michael D. Kern / Common iguana (Iguana iguana) albino, captive, from Central and South America

Michael D. Kern / Rhinoceros iguana (Cyclura cornuta) captive, from Hispaniola, Caribbean, Vulnerable species

Michael D. Kern / Albino Common Iguana (Iguana iguana) captive pair from Tom Crutchfield's collection, from Caribbean and South and Central America

Kevin Schafer / Galapagos land iguana (Conolophus subcristatus) Santa Cruz Is, Galapagos. Vulnerable species

Mark Carwardine / Marine Iguanas (Amblyrhynchus cristatus), the only marine lizard, basking on volcanic rocks. Galapagos Islands, Ecuador, South America. Book plate from Mark Carwardine's Ultimate Wildlife Experiences.

Pete Oxford / Cuban rock iguana (Cyclura nubila) Jardines de la Reina National Park, Cuba, Caribbean

John Abbott / Tourists watching large colony of Marine Iguanas (Amblyrhynchus cristatus) Punta Espinosa on Fernandina Island, Galapagos, August 2010

Ole Jorgen Liodden / Galapagos Land Iguana (Conolophus subcristatus) silhouetted against dawn light. Galapagos

Andy Rouse / Marine Iguana (Amblyrhynchus cristatus) walking along beach. Cerro Dragon, Galapagos, September.

Andy Rouse / Marine Iguana (Amblyrhynchus cristatus) head profile. Punta Espinoza, Galapagos, October.

Andy Rouse / Two Marine Iguana (Amblyrhynchus cristatus) basking on a volcanic rock. Puerto Egas, Galapagos, September.

Andy Rouse / Marine Iguana (Amblyrhynchus cristatus) with friendly Lava Lizard (Tropidurus) perched on its head. Puerto Egas, Galapagos, September.

Andy Rouse / Marine Iguana (Amblyrhynchus cristatus) in water. Punta Espinoza, Galapagos, October.

Tim Laman / Marine Iguanas (Amblyrhynchus cristatus) on the south coast of Espanola Island, Galapagos, Vulnerable species

Kim Taylor / Three-eyed Iguanid Lizard (Chalarodon madargascariensis) portrait standing.

Michele Westmorland / Cuban rock iguana (Cyclura carinata) walking in the sand, Iguana reserve on Little Water Cay, Turks and Caicos, Caribbean. Endangered

Stephen Dalton / Close up of eye of Common green iguana (Iguana iguana)

Stephen Dalton / Close up of ear of Common green iguana (Iguana iguana) showing tympanic membrane

Juan Carlos Munoz / Marine iguana {Amblyrhynchus cristatus} Plaza Island, Galapagos, January

Andy Rouse / Galapagos land iguana (Conolophus subcristatus) walking, North Seymour, Galapagos

Andy Rouse / Galapagos land iguana (Conolophus subcristatus) walking, Urbina Bay, Isabela Island, Galapagos (non-ex)

Tim Laman / Spines along the back of a marine iguana (Amblyrhynchus cristatus), Puerto Egas, Santiago Island, Galapagos Islands.

Tim Laman / Espanola (Hood) mockingbird (Nesomimus macdonaldi) standing on a Marine iguana (Amblyrhynchus cristatus), Espanola Island (Hood Island), Galapagos Islands.

Michael Pitts / Common Iguana {Iguana iguana} clinging to floating tree branch, Eastern Seaboard of Panama

Michael D. Kern / Close-up of eyes of Common iguana {Iguana iguana} composite. NOT FOR SALE TO TECHNOLOGYor FINANCIAL SERVICES INDUSTRIES.

Patricio Robles Gil / Fiji Crested Iguana (Brachylophus vitiensis) beside Heliconia, endemic to Fiji and Tonga

Juergen Freund / Common iguana baby (Iguana iguana) in a goose egg, studio shot

Mark Jones / Marine Iguana (Amblyrhynchus cristatus) pair resting after morning feeding, vulnerable, Punta Suarez, Hood Island, Galapagos Islands, Ecuador

Tui De Roy / Marine Iguana (Amblyrhynchus cristatus) breeding male basking with Sally Lightfoot Crab (Grapsus grapsus) scavenging dead skin, Hood Island, Galapagos Islands, Ecuador

Tim Fitzharris / Green Iguana (Iguana iguana) amid green leaves, Roatan Island, Honduras

Claus Meyer / Green Iguana (Iguana iguana) clinging to branch in tropical rainforest, Caatinga, Brazil

Tim Fitzharris / Green Iguana (Iguana iguana) portrait, Honduras

Tui De Roy / Marine Iguana (Amblyrhynchus cristatus) grazing seaweed in wave wash at low tide, Punta Espinosa, Fernandina Island, Galapagos Islands, Ecuador

Michio Hoshino / Marine Iguana (Amblyrhynchus cristatus) group with Sally Lightfoot Crabs (Grapsus grapsus), Galapagos Islands, Ecuador

Michio Hoshino / Marine Iguana (Amblyrhynchus cristatus) portrait, Galapagos Islands, Ecuador

Tui De Roy / Marine Iguana (Amblyrhynchus cristatus) pair sky pointing to keep cool in hot sun, Punta Espinosa, Fernandina Island, Galapagos Islands, Ecuador

Tui De Roy / Sally Lightfoot Crab (Grapsus grapsus) pair sharing boulder with Marine Iguanas (Amblyrhynchus cristatus) to escape high tide, Mosquera Island, Galapagos Islands, Ecuador

Tui De Roy / Sally Lightfoot Crab (Grapsus grapsus) group sharing boulder with Marine Iguana (Amblyrhynchus cristatus) trio to escape high tide, Mosquera Island, Galapagos Islands, Ecuador

Tui De Roy / Galapagos Land Iguana (Conolophus subcristatus) female searching for descent route into 1, 000 meter active caldera to nest, Fernandina Island, Galapagos Islands, Ecuador

Tui De Roy / Sally Lightfoot Crab (Grapsus grapsus) group sharing boulder with three Marine Iguana (Amblyrhynchus cristatus) group to escape high tide, Mosquera Island, Galapagos Islands, Ecuador

Tui De Roy / Marine Iguana (Amblyrhynchus cristatus) pair silhouetted on lava shore at sunset, Cape Douglas, Fernandina Island, Galapagos Islands, Ecuador

Tui De Roy / Galapagos Land Iguana (Conolophus subcristatus) rare social group basking together, Fernandina Island, Galapagos Islands, Ecuador

Tui De Roy / Marine Iguana (Amblyrhynchus cristatus) diving to graze on algae, Cape Douglas, Fernandina Island, Galapagos Islands, Ecuador

Tui De Roy / Marine Iguana (Amblyrhynchus cristatus) group in over heated sky pointing posture with lava flow entering sea, Cape Hammond, Fernandina Island, Galapagos Islands, Ecuador

Tui De Roy / Marine Iguana (Amblyrhynchus cristatus) group in overheated sky-pointing posture with new lava flow, Cape Hammond, Fernandina Island, Galapagos Islands, Ecuador

Tui De Roy / Marine Iguana (Amblyrhynchus cristatus) pair in surf resting on rocks, Santa Cruz Island, Galapagos Islands, Ecuador

Tui De Roy / Marine Iguana (Amblyrhynchus cristatus) mature male clings to lava rock along shoreline, Academy Bay, Santa Cruz Island, Galapagos Islands, Ecuador

Tui De Roy / Marine Iguana (Amblyrhynchus cristatus) with lava flow entering sea at night, Cape Hammond, Fernandina Island, Galapagos Islands, Ecuador

Tui De Roy / Marine Iguana (Amblyrhynchus cristatus) grazing on seaweed in wave washed shallows, Academy Bay, Santa Cruz Island, Galapagos Islands, Ecuador

Tui De Roy / Marine Iguana (Amblyrhynchus cristatus) grazing on seaweed in wave washed shallows, Academy Bay, Santa Cruz Island, Galapagos Islands, Ecuador

Michio Hoshino / Marine Iguana (Amblyrhynchus cristatus) couple, Galapagos Islands, Ecuador

Michio Hoshino / Galapagos Land Iguana (Conolophus subcristatus) sunning on rock, Galapagos Islands, Ecuador

Michio Hoshino / Galapagos Land Iguana (Conolophus subcristatus) and Prickly Pear (Opuntia sp) cactus, Galapagos Islands, Ecuador

Fred Bavendam / Marine Iguana (Amblyrhynchus cristatus) group photographed by tourist, Santiago Island, Galapagos Islands, Ecuador

Pete Oxford / Land Iguana portrait {Conolophus subcristatus} South Plaza Island, Galapagos

Pete Oxford / Marine iguana {Amblyrhynchus cristatus} Fernandina Is, Galapagos Islands, Ecuador

Pete Oxford / Marine iguana resting on driftwood {Amblyrhynchus cristatus} Fernandina Is, Galapagos

PREMAPHOTOS / Common iguana juvenile in forest (Iguana iguana) Costa Rica

Roland Seitre / Cayman Brac landscape, habitat for Grand cayman rock iguana (Cyclura lewisi), Western Indies

Roland Seitre / Indianapolis zoo worker holding a young Grand Cayman Blue iguana (Cyclura lewisi) from captive breeding program, Indianapolis zoo, Indiana, USA

Roland Seitre / Grand cayman blue iguana (Cyclura lewisi) attacking reflection in mirror, Indianapolis Zoo, Indiana, USA, Endangered species

Roland Seitre / Grand Cayman Blue Iguana (Cyclura lewisi), adult that has been reintroduced to the wild from captive breeding programme. Cayman Islands, Endangered species.

Roland Seitre / Grand Cayman Blue Iguana (Cyclura lewisi) hatchling and egg held in hands, captive, Cayman Islands National Trusts Blue Iguana Recovery Program, Queen Elizebeth Botanic Park, Grand Cayman. Endangered...

Roland Seitre / Grand Cayman Blue Iguana (Cyclura lewisi) captive Cayman Islands National Trusts Blue Iguana Recovery Program, Queen Elizebeth Botanic Park, Grand Cayman

Roland Seitre / Grand Cayman Blue Iguana (Cyclura lewisi) portrait, Cayman Islands, captive, endangered species

Roland Seitre / Cayman blue iguanas (Cyclura lewisi) in captive breeding program, Indianapolis Zoo, Indiana, USA, endangered species

Roland Seitre / Cayman blue iguanas (Cyclura lewisi) attacking its own image in mirror, captive, Indianapolis Zoo, Indiana, USA, Endangered species

Roland Seitre / Cayman blue iguana (Cyclura lewisi) reflected in mirror, captive, Indianapolis Zoo, Indiana, USA, Endangered species

Roland Seitre / Grand Cayman Blue Iguana (Cyclura lewisi) with mouth open defensively, Cayman Islands, captive

Kevin Schafer / Galapagos Land Iguana (Conolophus subcristatus) feeding on beach plant, North Seymour Island, Galapagos Islands, Ecuado r

Rod Williams / Fiji Banded Iguana (Brachylophus bulabula / fasciatus). Captive. Endemic to Central Fiji New species.

Kevin Schafer / Marine Iguana (Amblyrhynchus cristatus) walking on sand, San Cristobal Island, Galapagos Islands, Ecuador

Kevin Schafer / Marine Iguana (Amblyrhynchus cristatus) feeding on marine algae, Fernandina Island, Galapagos Islands, Ecuador

Kevin Schafer / Marine Iguana (Amblyrhynchus cristatus) swimming, Fernandina Island, Galapagos Islands, Ecuador

Kevin Schafer / Marine Iguana (Amblyrhynchus cristatus) on rock in water, Santiago Island, Galapagos Islands, Ecuador

Kevin Schafer / Marine Iguana (Amblyrhynchus cristatus) feeding on marine algae, Santiago Island, Galapagos Islands, Ecuador

Mike Wilkes / Marine Iguana (Amblyrhynchus cristatus) on sand. Floreana, Galapagos Islands.

Mike Wilkes / Lava Lizard (Tropidurus sp.) on back of Marine Iguana (Amblyrhynchus christatus). Fernandina, Galapagos Islands.

Mark Carwardine / Rhinoceros iguana (Cyclura cornuta) captive, from Haiti and Puerto Rico, Caribbean

Claudio Contreras / Common Spiny-Tailed Iguana (Ctenosaura similis) at ancient Maya temple, Uxmal, Yucatan Peninsula, Mexico, October.

Claudio Contreras / Common Spiny-Tailed Iguana (Ctenosaura similis), Uxmal, Yucatan Peninsula, Mexico, October.

Claudio Contreras / Common Spiny-Tailed Iguana (Ctenosaura similis), Uxmal, Yucatan Peninsula, Mexico, October.

John Cancalosi / Black tailed spiny iguana ( Ctenosaura similis) swallowing crab, Murcielago Island, Santa Rosa National Park, Costa Rica. Sequence 6 of 6

John Cancalosi / Black tailed spiny iguana ( Ctenosaura similis) swallowing crab, Murcielago Island, Santa Rosa National Park, Costa Rica. Sequence 5 of 6

John Cancalosi / Black tailed spiny iguana ( Ctenosaura similis) swallowing crab, Murcielago Island, Santa Rosa National Park, Costa Rica. Sequence 4 of 6

John Cancalosi / Black tailed spiny iguana ( Ctenosaura similis) swallowing crab, Murcielago Island, Santa Rosa National Park, Costa Rica. Sequence 3 of 6

John Cancalosi / Black tailed spiny iguana ( Ctenosaura similis) swallowing crab, Murcielago Island, Santa Rosa National Park, Costa Rica. Sequence 2 of 6

John Cancalosi / Black tailed spiny iguana ( Ctenosaura similis) swallowing crab, Murcielago Island, Santa Rosa National Park, Costa Rica. Sequence 1 of 6