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 Barrère died in 1944.
Georges Poitou died in 1989.
Georges Friedmann died in 1977.
Georges Dejagere died in 1955.
Georges Kwaïter died in 2011.
Georges Guibert died in 1997.
Georges Gorse died in 2002.
Georges Bouton died in 1938.
Georges Goyau died in 1938.