The smooth helmeted iguana (''Corytophanes cristatus''), also known as the helmeted iguana, the helmeted basilisk, the elegant helmeted lizard, and several other common names, is a species of New World

lizard Lizards are a widespread group of squamate reptiles, with over 7,000 species, ranging across all continents except Antarctica, as well as most oceanic island chains. The group is paraphyletic since it excludes the snakes and Amphisbaenia alt ...

in the family Corytophanidae. The species is native to southern Mexico, Central America, and northwestern South America.

Taxonomic history

Etymology

The smooth helmeted iguana is named for the prominent casque, or crest on the back of its head and neck which has the appearance of a helmet.

Evolutionary history

The Corytophanidae family of lizards is thought to have

Euramerica Laurasia () was the more northern of two large landmasses that formed part of the Pangaea supercontinent from around ( Mya), the other being Gondwana. It separated from Gondwana (beginning in the late Triassic period) during the breakup of Pan ...

n and

Laurasia Laurasia () was the more northern of two large landmasses that formed part of the Pangaea supercontinent from around ( Mya), the other being Gondwana. It separated from Gondwana (beginning in the late Triassic period) during the breakup of Pan ...

n ancestral beginnings, and is believed to have moved down to the tropics after the Eocene period cooling, approximately 33–56 million years ago.

Geographic range and habitat

''C. cristatus'' can be found ranging from

Chiapas Chiapas (; Tzotzil language, Tzotzil and Tzeltal language, Tzeltal: ''Chyapas'' ), officially the Free and Sovereign State of Chiapas ( es, Estado Libre y Soberano de Chiapas), is one of the states that make up the Political divisions of Mexico, ...

in southern Mexico to north-western

Colombia Colombia (, ; ), officially the Republic of Colombia, is a country in South America with insular regions in North America—near Nicaragua's Caribbean coast—as well as in the Pacific Ocean. The Colombian mainland is bordered by the Car ...

. The habitat it primarily occupies in this range is primary and secondary

mesic Mesic may refer to: * Mesic, North Carolina, a town in the United States * Mesic habitat, a type of habitat See also *Mesić (disambiguation) *Mešić Mešić is a Bosnian surname, a patronymic derived from the masculine given name '' Meša'', it ...

rain-forest. It lives predominantly in trees, but also hunts on the forest floor where it uses leaf litter as a micro-habitat.

Description

The smooth helmeted iguana is a medium-sized lizard with long slim legs and very long toes. It can be grey, olive, brown, black or reddish-brown with irregular blotches. The smooth helmeted iguana can change the color of its skin as a method of camouflage. As indicated by its name, the smooth helmeted iguana has a prominent crest on its head, which tapers to a saw-tooth ridge down its back. The crest is present in both males and females of the species, though the crest is larger in males. ''C. cristatus'' is approximately in snout-to-vent length (SVL) when mature. It is a non-heliotherm species, meaning that it does not use the sun to increase its body temperature. Rather, it maintains its body temperature at around , close to the temperature of the forest floor habitat where it lives. It is very wary of predators and freezes at the approach of danger from up to away.

Behavior and ecology

Reproduction

Adult females of ''C. cristatus'' lay five to six eggs in a depression on the forest floor. It is speculated that the crest on the head may be used in excavating the nest.

Diet

''C. cristatus'' feeds on insects, spiders, worms, and other lizards. ''C. cristatus'' is an extreme "sit and wait" predator, and its foraging is brief and infrequent. Therefore, this lizard is considered to be an opportunistic feeders. It is also a specialist feeder that preys on extremely large arthropods and cicadas when available. If it has no luck being a sit and wait predator, it will sometimes become an active predator and look for its next meal. Typically, if this is the method it chooses, it will choose prey that is slow and easy to capture.

Interactions with algae and fungi

The smooth helmeted iguana has been observed to remain motionless for extended periods of time. It is thought that this behavior has resulted in its skin being used as a novel growing substrate for a species of fungus, ''

Physarum pusillum ''Physarum'' is a genus of mycetozoan slime molds in the family Physaraceae. It contains the following species: *''Physarum albescens'' *'' Physarum album'' *'' Physarum andinum'' *'' Physarum bivalve'' *'' Physarum bogoriense'' *''Physarum ci ...

''. This species of lizard is also the only known vertebrate observed with a cormophytic plant growing on it.

Color change

The smooth helmeted iguana, like

chameleon Chameleons or chamaeleons (family Chamaeleonidae) are a distinctive and highly specialized clade of Old World lizards with 202 species described as of June 2015. The members of this family are best known for their distinct range of colors, bein ...

s and some other iguanas, has the ability to change its coloration from dark to light or ''vice versa'', which aids in thermoregulation when basking in sunlight.

Conservation

The smooth helmeted iguana is common and widespread throughout its native range. There are no current conservation concerns for this species although deforestation can be a localized threat to smooth helmeted iguana populations.