Ranger Fausto Llerena Sánchez poses with a tortoise representing the species that was named in his honor.

As much is known about the Earth and its inhabitants, we occasionally are surprised by what's out there. That point was driven home recently when, nearly 200 years after Charles Darwin set foot on the Galapagos Islands, a new species of giant tortoise was identified there.

This species, named Chelonoidis donfaustoi in honor of a longtime Galapagos National Park ranger who developing methods still used today for breeding endangered tortoises, was discovered on the island of Santa Cruz in the center of the Galapagos Archipelago. The discovery of the new species was detailed Wednesday in an article in the journal PLOS One.

This is a small and isolated group of tortoises that never attracted much attention from biologists previously,” said Dr. James Gibbs, a team member and conservation biologist at the SUNY College of Environmental Science and Forestry in Syracuse, New York, who participated in the first research expeditions to explore the new species’ range. “But we now know that they are as distinct as any species of tortoise in the archipelago. Their discovery and formal description will help these tortoises receive the scientific and management attention they need to fully recover.”

There are two populations of giant tortoises on the island: a large population on the west side in an area known as the “Reserve” and another on the lower eastern slopes around a hill named “Cerro Fatal.” Until the recent discovery, researchers believed that these populations belonged to the same species of tortoise. Genetic and morphological analyses conducted by an international group led by Dr. Gisella Caccone of Yale University have now clearly identified the two populations as separate species: the Western Santa Cruz Tortoise (Chelonoidis porteri) and the new Eastern Santa Cruz Tortoise.

Giant tortoises have been among the most devastated of all Galapagos creatures because of human exploitation, introduced species and habitat degradation. The Giant Tortoise Restoration Initiative is a collaborative project of the Galapagos National Park Directorate, Galapagos Conservancy, Caccone’s group at Yale University and others that works toward the long-term restoration of all Galapagos tortoise populations.

The new species is named in honor of Ranger Fausto Llerena Sánchez, known to his friends and colleagues as Don Fausto. Don Fausto dedicated 43 years (1971-2014) to giant tortoise conservation as a park ranger for the Galapagos National Park Directorate. He was the primary caretaker at the Tortoise Breeding and Rearing Center on Santa Cruz, which now bears his name. The restoration of several tortoise populations is due in part to Don Fausto’s dedication and efforts.