But each one of these is a different age, and if we can find out how old they are and then we can measure those chemical signals, this helps us to find out what's been going on in the ocean in the past.
Son de distintas idades, e se logramos determinar a de cada espécime e medir eses sinais químicos, iso axúdanos a saber que aconteceu no océano en épocas pasadas.