Fernandina Galápagos Tortoise
scientific name: Chelonoidis phantasticus
Last seen: 1906 in the Galápagos
Years lost: 112
Only one individual Fernandina Galápagos Tortoise has ever been found—on Fernandina Island, the youngest and least-explored of the Galápagos Islands. Could a large tortoise go undetected on an island? According to Himalayan mountaineering legend Eric Shipton, the odds of rediscovering a Fernandina Tortoise are at least better than those of finding a Yeti. An expedition in 1964 discovered putative tortoise droppings, and a fly-over in 2009 reported sightings of something tortoise-like from the air, renewing hope that this species may yet be holding on.
UPDATE (2.20.19): The Fernandina Galápagos Tortoise is the third of the Search for Lost Species' top 25 "most wanted" species to be found.