Added 8 December 2002. Last updated 27 December 2002 with details of differences between teiids and lacertids.

A look at the




The teiids are one of the smaller lizard families, found entirely in the New World and predominantly in South and Central America, with a fair number in the Caribbean and some species reaching the southernmost parts of the USA. The family was reduced in size when the subfamily Gymnopthalminae was raised to full family status, although the difference between the two groups is only detectable by specialists.

Teiids are not a family name to most people, but in fact most people in the area of their distribution will have seen them. Members of the genera Ameiva and Cnemidophorus are particularly widespread throughout the New World. Most herpetophiles will also be acquainted with the largest members of the Teiidae, the notorious tegus (Tupinambis sp.) Which in some ways can be considered analogous to the Old World monitors although not closely related. In fact the Teiidae can be considered most closely related to the Lacertidae of the Old World (Europe, Africa and Asia): like them they have well-developed limbs and long tails, while there is a fairly high occurrence of parthenogenesis (all-female reproduction) in the genera Cnemidophorus in particular (as well as Kentropyx and Teius) that corresponds to the same phenomenon found among many Lacerta species, particularly in the Caucasus and Asia Minor. Unlike the Lacertidae, however, the head shields of the Teiidae are not fused to the bones of the skull, and their teeth are not hollowed at the base.

Teiids as a rule are somewhat underrepresented in the animal trade, with a few important exceptions. This is partly because they have a reputation for being slightly more "tricky" in captivity, with the large tegus being stroppy to say the least and the smaller species (especially the Ameiva) being highly-strung and requiring large cages and plenty of hiding spaces. The Caiman Lizard (Dracaena) are not only large but are specialised mollusc feeders with a requirement for a large body of water that puts them beyond the reach of most private collectors.

As noted above, the Teiidae were traditionally divided into two subfamilies: the Teiinae and the Gymnopthalminae. The removal of the latter group leaves the one which however contains the best-known teiid genera. It must be said that in comparison with other lizard families (and indeed other reptile families) there is still little known about many of the species in the two groups, a situation that will hopefully be rectified in the near future.

The following is a guide to the teiid genera.

NAVIGATION: As this is a large page we have placed a couple of navigation links in each genus box. Click on "B" to go to the Bibliography, or "I" to go back up to the index (Quick Links).

Ameiva, Racerunners Callopistes, Dwarf Tegus Cnemidophorus, Whiptails
Crocodilurus Dicrodon Dracaena, Caiman Lizards
Kentropyx Teius Tupinambis, Tegus

Genus Common Name No. of species Distribution Notes
Ameiva Racerunners 33 USA (introduced to Florida)
Mexico, Guatemala, Panama, Nicaragua, Costa Rica, Belize, Honduras, Trinidad, Tobago, Brazil, Colombia, Surinam, French Guiana, Guyana, Venezuela, Bolivia, Ecuador, Peru, Argentina,
Caribbean inc. Lesser Antilles, Hispaniola, Jamaica, Puerto Rico and Cuba, poss. El Salvador
Centred on Caribbean. B I
Callopistes Dwarf and Monitor Tegus 2 Peru, S Ecuador (inter-Andean valleys), Chile (Southern Antofagasta to Maule Province)

Found in tropical S America: reasonably popular captives, need to be given adequate space. B I
Cnemidophorus Whiptails 57 S USA, Mexico, Guatemala, Belize, El Salvador, Honduras, Nicaragua, Honduras, Panama, Costa Rica Caribbean, Venezuela, Colombia, Brazil, Surinam, Paraguay, Uruguay, Bolivia, Argentina, Trinidad, Tobago, Caribbean, poss. French Guiana and Chile Centred on USA and Mexico. Contains some unisexual species. B I
Crocodilurus   1 French Guiana, Brazil,
Colombia, Venezuela, Peru, poss. Guyana and Surinam
Click here for a brief section on Crocodilurus under the heading "Life In the Water" (courtesy of the International Herpetological Society). B I
Dicrodon Desert Tegus  3 Ecuador & Peru Desert-dwelling genus of small lizards: apparently often the prey of Callopistes flavopunctatus. B I
Dracaena Caiman Lizards 2 Brazil, Colombia, Ecuador, Peru, French Guiana, Paraguay, Bolivia, poss. Guyana and Surinam Large semi-aquatic mollusc-eaters. B I
Kentropyx   9 Ecuador, Colombia, N Peru, Brazil, Bolivia, Caribbean, Venezuela, Guyana, Surinam, Trinidad, Paraguay, Argentina, poss. French Guiana and Tobago Contains some unisexual species. B I
Teius   3 Paraguay, Uruguay, Argentina, Brazil Contains some unisexual species. B I
Tupinambis Tegus 6 Mainly Brazil but also N & W Argentina, Uruguay, Bolivia, Peru, Colombia, Venezuela, Ecuador, Trinidad, Guyana, Surinam, French Guiana The tegus are popular terrarium subjects among those who prefer large or "giant" lizards. They are not recommended for beginners, nor for those without adequately large facilities to take care of them. B I

Bibliography - Teiidae

There seems to be no one single work (at least outside academic circles) dealing with the family Teiidae and/or the Gymnopthalmidae in their entirety. Of all the teiids and gymnopthalmids, tegus, ameivas and whiptails are usually the only ones mentioned at all in general books on lizard keeping, with the Dracaena species occasionally warranting a mention (in eg Sprackland). There is plenty of scientific literature available on Cnemidophorus, as these have been widely studied in the US, but arguably this may not be terribly accessible or even useful to the aspiring keeper.

Animal Life Encyclopedia Volume 6: Reptiles, Grzimek,1975 provided an overview of the general characteristics of teiids and of some of the lesser-known families.

Index of teiid-related articles from herpetological magazines.

Bibliography: specific genera

Giant Lizards, Robert Sprackland, TFH 1992. Contains brief but useful overviews of the tegus (Tupinambis), caiman lizards (Dracaena) and Callopistes flavipunctatus, the Monitor Tegu. This is a nice but expensive book, so if you are looking just for care details on the above-mentioned species, you may need to try one of the books below.

The General Care and Maintenance of Popular Monitors and Tegus, Michael Balsai, Advanced Herpetocultural Library. This is an updated version of Balsai's previous book in the same series, The General Care and Maintenance of Savannah Monitors. Apart from an enlargement of the care notes, mainly to include observations from other sources (mainly keepers!), the book includes an increased number of species, including a few of the desirable Australian monitors and the popular tegu. It goes a bit more in depth into the care of the Savannah Monitor than the Bartletts' book, but both are excellent.

Monitors, Tegus and Related Lizards, R D & P Bartlett, Barrons. The Bartletts are always informative and have had a good deal of experience with most cold-blooded terrestrial vertebrates. We particularly recommend this book if you wish to purchase one of the less commonly available monitors or a tegu. In addition there are useful sections on Callopistes (the Dwarf and Monitor Tegus) and Dracaena, the Caiman Lizards.

A-Z of Lizard Care, Bartlett & Bartlett, Barrons, 1995. Contains not only sections on tegus and monitors but also a brief but useful section on Ameiva species.

Echsen [Lizards] Vol 2, Rogner, Ullmer Verlag, 1992. Usually a very good source of information, although it has been pointed out to me by one source in at least one section there was a "theoretical" guess as to the captive requirements of a particular species that is in reality very hard to keep alive. However, of all the books I have found so far, this is the only one that offers any details on the lesser-known members of the Teiidae and Gymnopthalmidae. The notes on Callopistes are particularly interesting as Rogner discusses the details of winter dormancy. This book (and Vol 1) are available in English translation, but are substantially more expensive than most of the volumes mentioned above with the exception of Sprackland.


So far we have not been able to find any links to sites dedicated to or dealing with the Teiidae as such. If anyone knows of any we would be glad to hear from them.

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