It is Chelonoidis chathamensis and thanks to DNA tests, it has turned out to be a new species of giant Galapagos tortoise that had not yet been recorded by science.
According to researchers from Newcastle University, Yale University, the Galapagos Conservancy and other institutions, the northeastern part of the island, where these animals live, shows that almost 8,000 tortoises correspond to a different lineage than previously thought. So much so that the species of giant tortoise on San Cristóbal Island genetically corresponds to a different species, which was believed to be extinct since the beginning of the 20th century. Apparently, the DNA of these species had been accidentally mixed up for two decades.
The Galapagos, that natural evolutionary laboratory
It turns out that the DNA of today’s giant tortoises does not match the ancient bones of C. chathamensis . Instead, the San Cristóbal giant tortoises belong to another lineage that has never been formally described or given a scientific name . This also indicates that C. chathamensis is almost certainly already extinct.
“It seems likely that on San Cristóbal there were two species, not one, and if that is the case, the name C. chathamensis should be assigned to the extinct species, and the existing taxa should be given a new name” , Galapagos Conservancy, a US-based NGO, in a statement. The study has been published in the journal Nature Heredity.
Located in the Pacific about 1,000 km off the coast of Ecuador, the Galapagos Islands are a protected wildlife area and home to unique species of flora and fauna. It is an area that became popular thanks to the British naturalist Charles Darwin and his work on the evolution of species.
It is curious because in March 2021, a group of 36 endangered giant tortoises bred in captivity were transported back or to San Cristóbal. The new genetic analysis shows that they belong to this never-before-documented lineage.
Reference: Jensen, EL, Quinzin, MC, Miller, JM et al. A new lineage of Galapagos giant tortoises identified from museum samples. Heritage (2022). https://doi.org/10.1038/s41437-022-00510-8
Reference: Ministry of Environment, Water and Ecological Transition of the Government of Ecuador (New species of giant tortoise discovered in Galapagos).
