Lonesome George is the last remaining Galapogos Pinta tortoise, his species died out because of humans killing them - simple as. No, it really is that simple because there are no predators on Galapogos.
Lonesome George is currently about 170, and is one of the oldest creatures on Earth (the oldest is currently another tortoise at 175). Nobody is quite sure when (or if!) he will die because he's the only survivng example of his species.
The Galapagos Islands.
Lonesome Sundown died on 1995-04-23.
The final words in "Lonesome Dove" are "when I die, I'll die a free man on my own land."
Georges Toudouze died in 1974.
Georges Dargaud died in 1990.
Georges Darien died in 1921.
Georges Vuilleumier died in 1988.
Georges Guibourg died in 1970.
Georges Henein died in 1973.
Georges Barrère died in 1944.
Georges Leredu died in 1943.
Georges Heuyer died in 1977.