Jun 10, 2022 - Science

Galápagos tortoise thought extinct for 100 years confirmed alive

A specimen of the giant Galapagos tortoise Chelonoidis phantasticus at the Galapagos National Park on Santa Cruz Island in the Galapagos Archipelagoon February 19, 2019.

A specimen of the giant Galápagos tortoise Chelonoidis phantasticus at the Galápagos National Park on Santa Cruz Island after its discovery in 2019. Photo: Rodrigo Buendia/AFP via Getty Images

A giant tortoise species long believed extinct has been discovered living in the Galápagos Islands, scientists confirmed in a new study.

The big picture: An adult female Chelonoidis phantasticus, a species also known as the "fantastic giant tortoise," was the first of her kind that scientists had found since 1906, according to the study by Princeton and Yale researchers, published in the journal Communications Biology on Thursday.

  • Scientists named the tortoise Fernanda after the largely unexplored volcanic Fernandina Island on which she was found roaming among vegetation in 2019. She is estimated to be at least 50 years old.

The intrigue: Many ecologists initially doubted that Fernanda was actually a native fantastic giant tortoise because she lacks the striking saddleback flaring of the male specimen that was found on Fernandina Island in 1906.

  • Scientists speculated that her stunted growth may have distorted her features, according to a statement from Princeton University.

What they did: Researchers sequenced the genomes of Fernanda and the museum specimen of the male tortoise and compared them to the other 13 species of Galápagos giant tortoises.

  • The researchers found that the two Fernandina tortoises were members of the same species, genetically distinct from all others.

What they're saying: "For many years it was thought that the original specimen collected in 1906 had been transplanted to the island, as it was the only one of its kind," said Peter Grant, a Princeton professor of zoology, in a statement.

  • "It now seems to be one of a very few that were alive a century ago," Grant added.

Why it matters: Michael Russello, a biodiversity researcher at the University of British Columbia who wasn't involved in the study, told the Guardian the findings "are extremely exciting from both evolutionary and conservation perspectives," offering "a glimmer of hope that the species may yet survive."

Threat level: The International Union for Conservation of Nature's Red List classifies all 14 giant Galápagos tortoises as either vulnerable, endangered, critically endangered or extinct.

What to watch: Russello said the discovery indicated that a comprehensive study may be warranted to search for other surviving species of Chelonoidis phantasticus.

The bottom line: Yale University's Adalgisa Caccone, senior author of the paper, said in a statement that the "finding of one alive specimen gives hope and also opens up new questions, as many mysteries still remain." 

  • "Are there more tortoises on Fernandina that can be brought back into captivity to start a breeding program? How did tortoises colonize Fernandina, and what is their evolutionary relationship to the other giant Galápagos tortoises?" Caccone continued.
  • "This also shows the importance of using museum collections to understand the past," Caccone added.
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