The Fernandina Giant Tortoise was thought to be extinct for over a century, but one was recently discovered on the Galápagos Islands, which is famous for Charles' Darwin's work around evolution.
The last time the tortoise, called Chelonoidis phantasticus, was seen alive was in 1906.
The Fernandina giant tortoise was last seen alive in 1906, and experts thought it was extinct.
The tortoise was taken by boat to the Giant Turtle Breeding Center on the isle of Santa Cruz.
The Fernandina Giant Tortoise was listed as critically endangered and possibly extinct by the International Union for Conservation of Nature (IUCN), which said the species might have been threatened by lava flows on the volcanic island.
Washington Tapia, GTRI director and expedition leader, said that genetic studies are being carried out to "reconfirm" that the tortoise discovered belongs to the Fernandina Island species.
Many species of Galapagos tortoises have previously been killed over for food and for their oil over the past two centuries, according to the Galapagos Conservancy. Since then, no other example of this species has been found on the island of Fernandina, and some have even questioned whether they existed in the first place.
While on their trek the group found the tortoise scat and identified it positively as belonging to the Fernandina.
"As a biologist and someone who has dedicated my life to the pursuit of animals believed extinct, this is by far my greatest scientific accomplishment and proudest moment", Galante told Animal Planet.
The archipelago lies in the Pacific Ocean about 1,000 kilometres off Ecuador's mainland. The tracks and scent of other tortoises, believed to be of the same species, were also observed by the team.
Tortoises on the Galápagos islands have always been the subject of popular culture - including Lonesome George, the last Pinta Island tortoise made famous by David Attenborough for being the last of his species. The Galapagos Conservancy website says that when the Galapagos was established as a National Park in 1959, only "11 out of the 14 originally named populations remained and most of these were endangered if not already on the brink of extinction".
In captivity, the giant tortoises can easily live to more than 100 years.