The Galapagos giant tortoise Chelonoidis phantasticus is not extinct

Based on genomic data, the Galapagos giant tortoise species native to Fernandina Island appears to be alive and well, survived by at least one female after being considered extinct since 1906. The status of the Fernandina Island Galapagos giant tortoise (Chelonoidis phantasticus) has been a mystery, with the species known from a single specimen collected in 1906. The discovery in 2019 of a female tortoise living on the island provided the opportunity to determine if the species lives on. By sequencing the genomes of both individuals and comparing them to all living species of Galapagos giant tortoises, here we show that the two known Fernandina tortoises are from the same lineage and distinct from all others. The whole genome phylogeny groups the Fernandina individuals within a monophyletic group containing all species with a saddleback carapace morphology and one semi-saddleback species. This grouping of the saddleback species is contrary to mitochondrial DNA phylogenies, which place the saddleback species across several clades. These results imply the continued existence of lineage long considered extinct, with a current known population size of a single individual.

Automated summary

Based on genomic data and the discovery of an individual, it is suggested that the Galapagos giant tortoise species from Fernandina Island has not gone extinct and at least one female individual is still alive. The species was previously considered extinct since 1906 and its status has remained a mystery. Analysis of the genomes of the known individuals reveals that they belong to the same lineage and are distinct from other species.