There’s a new giant tortoise species in the Galapagos.

Science Daily reports that where scientists had thought there was only one kind of giant tortoise, there were actually two. Two kinds of giant tortoise living side by side:

The discovery of the new species, detailed in a study reported today (Oct. 21) in the journal PLOS ONE, is likely to help focus attention on the newly named Eastern Santa Cruz Tortoise (Chelonoidis donfaustoi), said Dr. James Gibbs, a team member and conservation biologist at the SUNY College of Environmental Science and Forestry in Syracuse, New York.

The discovery also calls attention to a longtime Galapagos National Park ranger who spent decades developing methods still used today for breeding endangered tortoises. His name is Fausto Llerena Sánchez, known to his friends and colleagues as Don Fausto. The new species’ Latin name was chosen in his honor.

Gibbs said Don Fausto successfully bred tortoises in Galapagos while many of the best zoos around the world have failed in their efforts to do so. “I recall many times seeing Don Fausto early on a Sunday morning, when most everybody else was still asleep, riding his bike to the captive rearing center to tend to the tortoises,” Gibbs said. “His dedication to his work has been inspirational.”

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.