The Genus Cyclura, also known as the ground iguanas. They are terrestrial iguanas (as opposed to arboreal). They come from the Caribbean, and are often kept as pets, although when you think of a stereotypical iguana, you are probably not thinking of one of the Cyclura, but rather the Green Iguana (Iguana iguana) or one of the Galapagos iguanas (Amblyrhynchus or Conolophus).
The family Iguanidae (Iguanas) have a very high degree of speciation, hence the longer than usual scientific names found below; many species have multiple sub-species.
Cyclura carinata bartschi:
Booby Cay rock iguana. Males are considerably larger than the females, with the males reaching 2 feet. Fewer than 300 are believed to remain on their home island of Booby Cay, in the Bahama Islands.
Cyclura carinata carinata:
Caicos rock iguana. A larger sub-species of C.carinata. Total length of males is about 30 inches. Currently under threat from human exploitation and habitat degradation.
Jamaican rock iguana; Jamaican iguana. The most endangered of the rock iguanas. Thought to be extinct for many years until rediscovered in 1990. Found only in the remote Hellshire Hills of Jamaica. Males reach 3.5 feet, females smaller.
Cyclura cornuta cornuta:
Hispaniolan rhinocerous iguanas. One of the largest, and most common rock iguanas. If you see a rhinoceros iguana, it is probably cornuta cornuta. Often seen in captivity, and is not regulated in trade in the US. Adult males reach 4 feet, and are heavily bodied. Older males develop large heads, with enlarged temporal areas, and pronounced, conical nasal horns.
Cyclura cornuta onchioppsis:
Navassa Island rhinocerous iguana. A smaller form of rhinocerous iguana, which is now thought to be extinct. Originally restricted to Navassa Island.
Cyclura cychlura cychlura:
Andros Island rock iguana. Overall length up to 34 inches. Restricted to Andros Island in the Bahamas. Females approximately the same size as males. A threatened species.
Cyclura cychlura figginsi:
Exhuma Island rock iguana. A subspecies found in relatively small numbers on the Central and southern Exhuma Cays. Smaller than the nominate form, at about 30 inches. Also a threatened species.
Cyclura cychlura inornata:
Allen's Cay rock iguana. Found on the Northern Exhuma Cays. About 32 inches in length. Again, a threatened species. Thought to be ~500 left in the wild.
Cyclura nubila caymanensis:
Cayman Island rock iguana. Found on the Cayman Islands (Little, Brac, and Grand). Total length longer than 40 inches for adult males, females are a little smaller.
Cyclura nubila lewisi:
Cayman Blue rock iguana; Blue iguana. Slightly larger than C. nubilia caymanensis. Found in the more inaccessible regions of Grand Cayman. Until recently, we thought that there were 250 surviving individuals, but it has recently been found that the introduced Cayman Island rock iguanas have been interbreeding with this species. It is now thought that only 75 pure-blooded individuals are left. Classified as an endangered species.
Cyclura nubila nubila:
Cuban ground iguana; Cuban iguana. The largest and most secure of the three species. The largest of the Rock Iguanas, with adult males reaching a full 5 feet. Females tend to reach about 4.5 feet.
Anegada Island ground iguana. Restricted to Anegada Island, in the British Virgin Islands. Adult males reach 45", females are somewhat smaller.
Hispanioloan rock iguana. One of two coexisting Rock Iguanas on the island of Hispaniola. This is the smaller species of the two (the other being the Rhinocerous Iguana), reaching about 35 inches.
Cyclura rileyi cristata:
Sandy Cay rock iguana. Restricted to the southern Exhumas, but is not sympatric to C.cychlura. Reaches about 2 feet in length.
Cyclura rileyi nuchalis:
Crooked Acklins rock iguana. Also restricted to the southern Exhumas. Reaches about 22 inches.
Cyclura rileyi rileyi:
San Salvador rock iguana. Restricted to the Cay of San Salvador in the Southern Exhuma Islands of the Bahamas. Reaches about 2 feet.