Added 18 July 2000. Last updated 30 December 2014: corrected link to iguanid genera.
The iguanids constitute a family of about 650-700 lizard species, distributed entirely throughout the New World (the Americas) apart from one species in the Fiji islands and two genera in Madagascar. They are in many ways the New World equivalent of the agamid lizards and fill similar ecological niches. Often the degree of similarity between an iguanid species and its agamid equivalent is uncanny.
Mention the word iguanid to most people, even some herpetologists, and they will automatically think of the green iguana as a representative species. Yet this is only a part of the picture, maybe less than half of the picture. For every one of the large iguana species (some of which do grow to considerable sizes), there are many much smaller iguanids. Green anoles, collared lizards, basilisks and side-blotched lizards are all iguanids.
This sheer diversity among the iguanid family has recently led to some controversy over whether it is actually a valid family, with some workers calling for the breakup of the family into no less than eight new and separate units. I give both systems here, acknowledging my debt to the book Green Iguanas and other Iguanids by Dr Hubert Bosch and Heiko Werning. Please see the Bibliography for more details.
For a list of the individual genera, click here.
|
Complex/Subfamily |
Species |
|
Sceloperinae |
Spiny lizards and fence lizards (Sceloporus), collared lizards (Crotaphytus), earless lizards (Holbrookia) and horned "toads", Phrynosoma. This group is supposedly "primitive" (Bosch & Werning) and appears to be centred on North America. |
|
Tropidurinae |
"Keel-tailed" lizards - besides the curly-tails (Leiocephalus)) and "snow swifts" (Liolaemus), includes a good number of largely little-known iguanids of South America, plus the two iguanid genera of Madagascar, Oplurus and Chalorodon. |
|
Iguaninae |
"True iguanas" - the largest members of the family, all fairly similar in shape. It includes the green iguanas (Iguana iguana), rhinoceros- or island iguanas (Cyclura spp), chuckwalls (Sauromalus spp), Fiji iguanas (Brachylophus) and the rare Galapagos iguanas, the marine (Amblyrhynchus) and the land (Conolophus). |
|
Basiliscinae |
Basilisk lizards, including the Laemanctus (cone-heads) and Corytophanes (helmet-head) lizards. All of these lizards can be characterised by having various adornments such as casques (helmets), crests or the like. |
|
Anolinae |
Anole lizards, a group containing a large number of species distributed around the warmer parts of North-, Central- and South America and the Carribean, plus members of the "false chameleons" (Chameleolis) and other relatively unknown South American genera. |
According to the EMBL Reptile Database some years ago, there were also a few genera not assigned to any subfamily: Abas, Ceiolaemus, Cophosaurus, Garbesaura, Microlophus, Pelusaurus, Plesiomicrolophus and Vilcunia.
|
Family |
Species |
|
Corytophanidae |
Basilisk lizards (Basiliscus), Laemanctus (cone-heads) and Corytophanes (helmet-head) lizards. All of these lizards can be characterised by having various adornments such as casques (helmets), crests or the like. Basically unchanged from the "old system". |
|
Crotaphytidae |
Collared and leopard lizards, Crotaphytus and Gambelia. Both genera live in fairly arid areas and are very predaceous. |
|
Hoplocercidae |
Tropical spiny-tails: the three fairly small genera of Hoplocercus (monotypic), Morunasaurus and Enyalioides. |
|
Iguanidae |
"True iguanas" - the largest members of the family, all fairly similar in shape. It includes the green iguanas (Iguana iguana), rhinoceros- or island iguanas (Cyclura spp), chuckwalls (Sauromalus spp), desert iguanas (Dipsosaurus), spiny iguanas Ctenosaurus), Fiji iguanas (Brachylophus) and the rare Galapagos iguanas, the marine (Amblyrhynchus) and the land (Conolophus). Many if not most are herbivorous, although they occupy a wide range of habitats. |
|
Opluridae |
The two iguanid genera of Madagascar, Oplurus and Chalorodon, sometimes referred to as Madagascan spiny-tails. |
|
Polychridae |
Anole lizards, a group containing a large number of species distributed around the warmer parts of North-, Central- and South America and the Carribean, plus members of the "false chameleons" (Chameleolis) and other relatively unknown South American genera. |
|
Phrynosomatidae |
North American: roughly equivalent to the subfamily or complex Sceloperinae under the old system: includes spiny lizards, swifts and fence lizards (Sceloperus), earless lizards (Holbrookia) and horned "toads", Phrynosoma, plus the small lizards of the genera Petrosaurus, Uma, Urosaurus and Utaand the monotypic (single-species) genera CallisaurusCophosaurus, . This group is still centred on North America but excludes collared lizards and their relatives (Crotaphytus and Gambelia), . |
|
Tropiduridae |
"Keel-tailed" or neotropical ground lizards - besides the curly-tails (Leiocephalus)) and "snow swifts" (Liolaemus), includes a good number of largely little-known iguanids of South America, but excluding the two iguanid genera of Madagascar, Oplurus and Chalorodon. There are further subdivisions in this rather large and confusing grouping: see the EMBL database page for further details. |
The EMBL Reptile Database seems to compromise between the two systems by adopting the "new system" but demoting the superfamily Iguanoidae and its families to the family Iguanidae and subfamilies respectively: thus you get subfamily Iguaninae, subfamily Polychrinae, etc.
Green Iguanas and other Iguanids, Dr Hubert Bosch and Heiko Werning, TFH 1996 (originally published in German, 1991, as Leguane). Most German herpetologists write very knowledgeably, and TFH have excelled themselves in snapping this one up and publishing it in a good English translation. Not only does this book give excellent care advice on all the major species of iguanid that are kept in the terrarium, but it also gives information on the classification of the iguanids, a reasonably good section on health care, and a most welcome bonus, a guide to many of the lesser-known iguanids, particularly those of South America (how many herpetologists have heard of Proctotretus pectinatus, Chalarodon madagascariensis or the ant-eating Uracentron azureum? The book is one of TFH's hardback editions and thus somewhat more expensive than usual (about £15-£16 in the UK) but well worth the money if you are interested in iguanid lizards. Recommended.
The German site Repti-Box has a very useful summary table of information about some of the species of iguana contained in these pages. Although in German, the actual care details such as temperature ranges and humidity are fairly easy to pick up.
Index of Iguanid-related articles from herpetological magazines.