Lonesome George, the last remaining giant Galapagos tortoise, died on Sunday at 100-years-old.
The tortoise was found in 1972 and became a symbol of Ecuador's Galapagos Islands, attracting around 180,000 visitors last year.
Scientists had been trying to get George to mate since 1993, with no success.
The giant Galapagos tortoise, which can live up to 200-years-old, was among the species that helped Charles Darwin formulate his theory of evolution in the 19th century.
The Galapagos National Park will carry out a necroscopy to determine the cause of death and is considering embalming George's body so that it can be displayed in the park.