 In 1938 , Bernard C. Lewis of the Institute of Jamaica joined an Oxford University biological expedition to the Cayman Islands . Lewis was able to obtain two blue iguanas , a male and a female , which were later lodged with the British Museum of Natural History . Chapman Grant , in a monograph published in 1940 , formally described the blue iguana for the first time as Cyclura <unk> lewisi . Schwartz and Carey established the trinomial ( Cyclura nubila lewisi ) in 1977 . They held that the blue iguana was a strongly distinct subspecies of the Cuban iguana ( C. nubila ) , the species which it evolved from and can breed with . They emphasized its overall bright blue coloration , and noted that further study could reveal it to be a distinct species . Frederick Burton reclassified the blue iguana as a distinct species in 2004 , after years of research comparing scale counts on the heads of Caribbean iguanas , including those found on Little Cayman , Cayman Brac , Cuba , and the Bahamas , as well as mitochondrial DNA analysis performed by Dr. Catherine Malone , to re @-@ examine the phylogeography of the different species . 
