There are 2 species of iguana in the park- hard to tell them apart because they are very variable in color and spine length, etc. The black spiny tailed iguana and the green iguana seem to live amiably together-- don't know if they could/would/do hybridize, but if they do that would make it even more confusing. The green iguana is extremely variable in color- I *think* the orange color indicates a male in breeding condition- and I *think* it's only the adult green males that develop a large round disk on the throat, and I *think* it's only the black spiny tail who can have rings of bumps around their tails, and I *think* the females of both species have shorter spines on the neck/back but I woudn't bet on being right on any count.
If you click on any pic it'll take you to Ipernity where I've added notes to the pics.
( 6 iguana pics )