A new species of iguana with unusual pink skin has been discovered by scientists on the island where Charles Darwin first developed his theory of evolution.
The large lizard, which is at risk of extinction, has rose-coloured scales and only lives on one volcano in the Galapagos Islands.
Darwin, whose 200th birthday will be celebrated on February 12, observed both marine and land iguanas when he visited the archipelago in 1835.
The way the creatures adapted themselves to their surroundings helped to develop his revolutionary ideas about natural selection.
But he never explored the Volcan Wolf volcano on the island of Isabela and therefore did not see the pink iguana.
The creature was first spotted in 1986 by park rangers but was dismissed as a curiosity and soon forgotten.
It is only now that scientists have discovered that the “rosada” – or pink – iguana is a species in its own right after comparing its genes with other land iguanas on the Galapagos.
There were also physical differences, besides the striking pink and black-striped colouring. Pink iguanas had flat head scales, unlike other land iguanas, and a thick fatty crest on the back of the neck with small conical scales.
Action is now needed to prevent this scientifically valuable creature becoming extinct, say the researchers writing in the journal Proceedings of the National Academy of Sciences.
The discovery comes as seventeen previously unknown species of reptiles and amphibians were found in the threatened rainforests of eastern Tanzania.
The new species, which include chameleons, tree frogs and snakes, were discovered by scientists from the Natural Science Museum of Trento in Italy.
The discovery shows the rich biodiversity of the area which is under threat from fire, logging, collection of wood for fuel and land clearance for cultivation.