Can You Tell a Turtle’s Age by Its Shell?
By looking at its shell, you can tell the age of a young turtle, but not of an old turtle. The bony shells of turtles are covered with thin plates called shields. “Growth rings” accumulate on most turtle’s shields as they grow.
Each ring stands for a year’s growth. These rings can indicate the age of a turtle up to about fifteen years. After that, you can no longer tell a turtle’s age by counting the rings. They have either become too crowded together or have begun to wear off.
Soft shelled turtles, or those with smooth, hard shells, don’t have growth rings. The average lifespan of many turtles is well under 20 years. The really old turtles are generally tortoises and almost always live in protected places.