An overlooked pink species of land iguana in the Galapagos

Despite the attention given to them, the Galapagos have not yet finished offering evolutionary novelties. When Darwin visited the Galapagos, he observed both marine (Amblyrhynchus) and land (Conolophus) iguanas but did not encounter a rare pink black-striped land iguana (herein referred to as "rosada,'' meaning "pink'' in Spanish), which, surprisingly, remained unseen until 1986. Here, we show that substantial genetic isolation exists between the rosada and syntopic yellow forms and that the rosada is basal to extant taxonomically recognized Galapagos land iguanas. The rosada, whose present distribution is a conundrum, is a relict lineage whose origin dates back to a period when at least some of the present-day islands had not yet formed. So far, this species is the only evidence of ancient diversification along the Galapagos land iguana lineage and documents one of the oldest events of divergence ever recorded in the Galapagos. Conservation efforts are needed to prevent this form, identified by us as a good species, from extinction.