Michoacan dwarf spiny-tailed iguana (Ctenosaura clarki)

Michoacan dwarf spiny-tailed iguana
Loading more images and videos...

Michoacan dwarf spiny-tailed iguana fact file

Michoacan dwarf spiny-tailed iguana description

GenusCtenosaura (1)

Also known as the Balsas armed lizard, the Michoacan dwarf spiny-tailed iguana (Ctenosaura clarki) is a small brown and tan coloured lizard. It belongs to a group of poorly understood iguanas, the Ctenosaura, that all share a characteristic spiny tail (2).

The most distinguishing feature of the Michoacan dwarf spiny-tailed iguana is its large and muscular tail, which is covered with sharp, spiny scales. The tail is used to slap prey or an opponent in an attempt to inflict an injury, sometimes resulting in impressive wounds (3).

Also known as
Balsas armed lizard.
Male length: 18 - 28 cm (2)
Female length: 16 - 20 cm (2)

Michoacan dwarf spiny-tailed iguana biology

A semi-arboreal species (1), the Michoacan dwarf spiny-tailed iguana generally rests during the night in a hollow cavity in tree cacti. The iguana will block the entrance to the cavity by arching its large, muscular spiny tail. As the iguana grows, it will take shelter in larger cavities (1) (3).

In general, most species of spiny-tailed iguanas will venture out from their retreats during the day, when the outside temperature reaches a comfortable level. The iguanas then bask in a sunny area until their optimum body temperature is reached. Reptiles are unable to maintain their own body temperature and therefore rely on sources of heat from the environment, such as the sun, to increase the temperature of the body and provide them with enough energy to sustain their daily activities (6).

Throughout the day, spiny-tailed iguana species will usually forage, bask, rest and display, before returning to their retreats as the sun starts to set. Displays typically involve a male spiny-tailed iguana patrolling its territory by standing high on its legs, flattening its body, and bobbing its head with its mouth open to intimidate other males (2).

Reproduction in spiny-tailed iguanas begins with the male chasing the female. Following capture, the male uses its front legs to pin down the female, and uses its mouth to hold the female by the back of the neck while attempting to copulate. Eight to ten weeks after mating, the female digs a nest in the ground in which to lay the eggs. The eggs take around 90 days to hatch, depending on the temperature. Upon hatching, the young iguanas immediately dig their way out of the underground nest (2).


Michoacan dwarf spiny-tailed iguana range

The Michoacan dwarf spiny-tailed iguana is found only in the Mexican state of Michoacán, from which it takes its name. Within Michoacán, it occurs in the Tepalcatepec Valley and at the Michoacán - Guerrero border (4).


Michoacan dwarf spiny-tailed iguana habitat

The Michoacan dwarf spiny-tailed iguanainhabits dry, hot, cactus-covered rocky hillsides (5).


Michoacan dwarf spiny-tailed iguana status

The Michoacan dwarf spiny-tailed iguana is classified as Vulnerable (VU) on the IUCN Red List (1).

IUCN Red List species status – Vulnerable


Michoacan dwarf spiny-tailed iguana threats

The primary threat to the Michoacan dwarf spiny-tailed iguana is the loss of its habitat (1), but it is also threatened by collection for the international pet trade (1).


Michoacan dwarf spiny-tailed iguana conservation

The Michoacan dwarf spiny-tailed iguana is protected by law in Mexico (1), but there are not known to be any other conservation measures in place for this threatened species.

It has been recommended that more research is carried out into the biology and habitat of this species (1), which will help inform any future conservation measure that are implemented.


Find out more

Learn more about the conservation of iguanas and other reptiles:

Find out about conservation in Mexico:



This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:

This species information was authored as part of the Arkive and Universities Scheme.


An animal which spends a large amount of time in trees.
An area occupied and defended by an animal, a pair of animals or a group.


  1. IUCN Red List (June, 2011)
  2. Malfatti, M. (2007) Genus Ctenosaura. West Coast Iguana. Available at:
  3. Pianka, E.R. and Vitt, L.J. (2003) Lizards: Windows to the Evolution of Diversity. University of California Press, California.
  4. Perez-Ramos, E. and Saldana-De la Riva, L. (2005) Distribucion ecologica de Ctenosaura clarki (Reptilia: Iguanidae) en Guerrero y Micoacan, Mexico. Revista de Zoologia, 16: 16-24.
  5. West Coast Iguana (June, 2011)
  6. Halliday, T. and Adler, K. (2002) The New Encyclopedia of Reptile and Amphibians. Oxford University Press, Oxford.

Image credit

Michoacan dwarf spiny-tailed iguana  
Michoacan dwarf spiny-tailed iguana

© Gunther Koehler

Gunther Koehler
Curator of Herpetology
Senckenberg, Forschungsinstitute und Naturmuseen
Sektion Herpetologie
Senckenberganlage 25
United Kingdom


Link to this photo

Arkive species - Michoacan dwarf spiny-tailed iguana (Ctenosaura clarki) Embed this Arkive thumbnail link ("portlet") by copying and pasting the code below.

Terms of Use - The displayed portlet may be used as a link from your website to Arkive's online content for private, scientific, conservation or educational purposes only. It may NOT be used within Apps.

Read more about



MyARKive offers the scrapbook feature to signed-up members, allowing you to organize your favourite Arkive images and videos and share them with friends.

Play the Team WILD game:

Team WILD, an elite squadron of science superheroes, needs your help! Your mission: protect and conserve the planet’s species and habitats from destruction.

Conservation in Action

Which species are on the road to recovery? Find out now »

Help us share the wonders of the natural world. Donate today!


Back To Top