iPhoneOgraphy – 23 Oct 2016 (Day 297/366)
The rhinoceros iguana also known as “Goliath Dragons” (Cyclura cornuta) is a threatened species of lizard in the family Iguanidae that is primarily found on the Caribbean island of Hispaniola, shared by the Republic of Haïti and the Dominican Republic. They vary in length from 60 to 136 centimetres (24 to 54 in) and skin colors range from a steely gray to a dark green and even brown. Their name derives from the bony-plated pseudo-horn or outgrowth which resembles the horn of a rhinoceros on the iguana’s snout.
The rhinoceros iguana is a species of lizard belonging to the genus Cyclura. The generic name (Cyclura) is derived from the Ancient Greek cyclos (κύκλος) meaning “circular” and ourá (οὐρά) meaning “tail”, after the thick-ringed tail characteristic of all Cyclura. The rhinoceros iguana’s specific name, cornuta, is the feminine form of the Latin adjective cornutus, meaning “horned” and refers to the horned projections on the snouts of males of the species. The species was first identified by Piere Joseph Bonnaterre in 1789.
In addition to the nominate race (Cyclura cornuta cornuta) found on Hispaniola, there are two other subspecies of Cyclura cornuta, the Mona ground iguana (Cyclura cornuta stejnegeri) and the Navassa Island iguana (Cyclura cornuta onchiopsis), although the latter subspecies is believed to be extinct in the wild.
The rhinoceros iguana, like other members of the genus Cyclura, is a large-bodied, heavy-headed lizard with strong legs and a vertically flattened tail. A crest of pointed horned scales extends from the nape of their neck to the tip of their tail. Their color is a uniform gray to brown drab. Most adults weigh 4.56 kilograms (10.1 lb) to 9 kilograms (20 lb).
These iguanas are characterized by the growth of bony prominent tubercles on their snouts which resemble horns. Dr. Thomas Wiewandt, who spent an extended period on Mona Island studying Cyclura cornuta stejnegeri, suggested that the horns, along with lateral spines and prominent parietal bulges, function as protective armor against sharp rocks or as defensive tools to facilitate the escape of males from the grasp of one another. Males possess an adipose pad in the form of a helmet on the occipital region of the head, and a large dewlap. This species, like other species of Cyclura, is sexually dimorphic; males are larger than females, and have more prominent dorsal crests and “horns” in addition to large femoral pores on their thighs, which are used to release pheromones.