{ { speciesbox
| status = LC
| status_system = IUCN3.1
| status_ref =
| genus = Uracentron
| species = azureum
| authority = (Linnaeus, 1758) | synonyms = Lacerta azurea Linnaeus, 1758 Stellio brevicaudatus Latreille, 1802Stellio azureus – Latreille, 1802 Uromastyx azurea – Merrem, 1820Uracentron azureum – Kaup, 1826 Doryphorus [sp. ?] – Cuvier, 1829Urocentron azurea – Wagler, 1830 Uranocentron [sp. ?] – Gray, 1831Doryphorus azureus – Duméril & Bibron, 1837 Uranocentrum [sp. ?] – O'Shaugnessy, 1881 Uracentron azureum – Boulenger, 1885Hoplurus azureus – Schlegel, 1858 Tropidurus azureum – Frost 1992Uracentron azureum guentheri Boulenger 1894 Uracentron guentheri Boulenger, 1894Uracentron azureum werneri Mertens, 1925 Uracentron werneri Mertens, 1925 }}
The green thornytail iguana (Uracentron azureum) is an arboreal species of lizard from the Amazon rainforest and forests in the Guiana Shield. It is found in Colombia, Guyana, Suriname, French Guiana, northeastern Peru, southern Venezuela, and northern Brazil.Avila-Pires (1995). Lizards of Brazilian Amazonia (Reptilia: Squamata). Zoologische Verhandelingen 299(1): 1-706 As in U. flaviceps (the only other species in the genus), U. azureum primarily feeds on ants.
The green thornytail iguana can reach about in snout–vent length and has a relatively short, spiny tail. It has three distinct subspecies, which sometimes have been recognized as separate species: the nominate subspecies is bright green with distinct blackish bands and is found in the northeastern part of the green thornytail iguana's range, the southwestern T. a. guentheri is duller with greyish or brownish rear body and tail, and the northwestern T. a. werneri'' is almost all green without distinct markings in adults.