Ecuador's Galapagos Islands officially have a new species of giant tortoise, after a groundbreaking study was released Wednesday.
Published in the science journal PLOS ONE, the study revealed that one of the largest islands in the Galapagos archipelago is home to two species of giant tortoise — not one — as previously believed.
Until now, the island of Santa Cruz was believed to be home to just the Chelonoidis porteri tortoise, with the population divided between two population groups on either side of the island. However, in 2005 researchers began to suspect the two population groups might not be the same species.
Although the two groups of tortoises live just 20 kilometers away from each other, they have evolved independently for potentially millions of years, according to Adalgisa Caccone, a geneticist at Yale University.
“People knew they were a little bit different but they didn’t know how different,” Caccone told the New Scientist.
The new species, dubbed Chelonoidis donfaustoi, is now believed to have arrived on Santa Cruz as many as 1.3 million years after C. porteri washed up on the other side of the island. Researchers say the two groups rarely interbreed. They look similar, but not identical.
“Although individuals of both populations exhibit a domed carapace morphology, morphological analyses indicated that tortoises from the two populations differ in size and shape,” the PLOS ONE study found.
The new C. donfaustoi species has just 250 members, compared to the 2000-4000 C. porteri tortoises. With the formalization of the discovery of the new species, the Galapagos Islands is now officially home to 11 tortoise species living in the wild.
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"Animals of the Galapagos Islands"