Cyclura cornuta stejnegeri

The Mona ground iguana (Cyclura stejnegeri) is a species of Cyclura closely related to the rhinoceros iguana (Cyclura cornuta). It is endemic to Mona Island, Puerto Rico and is the largest native terrestrial lizard in Puerto Rico. The Mona ground iguana is a species belonging to the genus Cyclura. It was named by Thomas Barbour and G.K. Noble as a species in 1916. In 1937, Barbour considered it to be a subspecies of Cyclura cornuta. The Mona ground 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. Its subspecific name, stejnegeri honors Leonhard Hess Stejneger, who, when writing his Herpetology of Porto Rico in 1902, suspected this was a new species. Debate continues as to whether this is a valid subspecies and not a different species in its own right. It is known in some scientific circles as Cyclura stejnegeri. Still, others consider it a regional variant of the parent species. The Mona ground iguana is a large-bodied, heavy-headed lizard with strong legs and a vertically flattened tail which is capable of reaching 1.22 metres in length (from snout to tail). A crest of pointed, horned scales extends from the nape of the neck to the tip of the tail. The color is a uniform gray to olive drab with slight brown or blue colorations. Juveniles differ from adults in that they have gray transverse bands across their bodies. These bands last until they are sexually mature at about three years of age. Males possess bony, prominent tubercles on their snouts resembling horns, adipose pads in the form of a helmet on the occipital region of their heads, and large dewlaps. This species, like other species of Cyclura, is sexually dimorphic; males are larger than females, and have more prominent dorsal crests, 'horns' and femoral pores on their thighs, which are used to release pheromones. Mona ground iguanas are diurnal and spend most of the day basking in the sun conserving energy. Mona ground iguanas are endemic to Mona Island, Puerto Rico. They are scattered through the entire island, though the Southwest part of the island is only used during the nesting season. They live a considerable portion of their lives underground, and are usually found in talus slopes, caves and sinkhole depressions. The average depth underground that they can be found is 1.5 metres. Although Mona ground iguanas use the whole island as their habitat, only 1% of the territory, located on the southwest coast, is suitable for nesting because it contains loose sand and receives direct sunlight. The females bury their eggs in the sand and the sunlight incubates the eggs. Males reach sexual maturity at a size of 28–31 cm in length from snout to vent, usually in their third to fourth year, while females mature one year later at a size of 35–40 cm. Nesting season begins in the second week of June. Usually, one female mates with more than one male in the two weeks the mating season lasts. Copulation may last from 15 sec to 2 mins and 15 sec. One month later, nesting begins. Females will dig a tunnel 3-foot (0.91 m) long located one to two feet underground, where they deposit from five to 19 eggs, with 12 being the average. They will guard their nests for several days, but provide no parental care for the hatchlings, which hatch three months later. Hatchlings measure, on average, 32 cm and weigh 73.7 grams and grow at a rate of 5.23 cm per year.