#1 – Eastern box turtle
The Eastern box turtle (Terrapene carolina) is native to the U.S. and is extremely long lived (over 125 years), slow to mature, and has relatively few offspring per year. Though they are very long lived, these characteristics, along with a propensity to get hit by cars and agricultural machinery, make all box turtle species particularly susceptible to human casued deaths.
Although turtles and especially their cousins tortoises actually look old and wrinkly from youth, on a cellular level the passage of times appears to cause little senescence.
There are no definitive answers for why most turtles live so long and maintain their youth, but it is thought that their slow metabolisms, naturally healthy diets and low-stress lifestyles are the key components. Think about it… how many stressed looking tortoises have you seen?!