Although there are records of turtles that have lived past 100 years, today zoologists can look at rings in a turtle's shell much like the rings in a tree, to determine that most chelonians live only 20 or 30 years. True, some sea turtles can live 50 or 60 years, but in any case their lifetimes are far shorter than people had imagined.
雖然人類記錄的烏龜，壽命有長達百歲以上者，今天動物學者由烏龜腹甲上類似樹木年輪的生長環估算，烏龜平均壽命不過二、三十歲，海龜雖可活到五、六十歲，仍遠遜於人們想像的數字。