EPOW - Ecology Picture of the Week

Baja California Spiny-tailed Iguana (Ctenosaura hemilopha macrolopha), Family Iguanidae
Arizona-Sonoran Desert Museum, southern Arizona USA (introduced)

Explanation:   Like some modern-day dinosaur, this Baja California Spiny-tailed Iguana is sunning itself on rocks and exhibiting its characteristic namesake spiny tail. 

Also note the row of dorsal scales on neck and back.  Like the Common Chuckwalla, this species inhabits crevices in rocks and may inflate its body to wedge itself in, with the heavy skin folds on the sides expanding out.  It also will use woodpecker cavities in trees and cacti.  

This species is found in Mexico but has been introduced here at the Arizona-Sonora Desert museum near Tucson, Arizona, apparently in the 1970s, and has since established a local feral breeding population.  

They have been known to live nearly 10 years in captivity.  

  
Acknowledgment:  My thanks to EPOW reader Henk Zwartepoorte for pointing out my previous error incorrectly identifying this as common chuckwalla.  Mr. Zwartepoorte works with reptiles, including species of Ctenosaura, at the Rotterdam Zoo.