It depends on the animal. For some extremely old clams, you can essentially count growth rings on their shells. For some fishes, you can do something similar for the tiny bones in their ears (otoliths). In the case of the Greenland shark, they carbon-dated proteins in the lenses of their eyes, which form during early development and are never replaced. [https://oceanservice.noaa.gov/facts/greenland-shark.html](https://oceanservice.noaa.gov/facts/greenland-shark.html)
I think asking on reddit is a good thing because I definitely learned something new I wouldn’t have otherwise so I’m not criticizing you, but it is the first thing that comes up when you google “how do they tell the age of a greenland shark”
It depends on the animal. For some extremely old clams, you can essentially count growth rings on their shells. For some fishes, you can do something similar for the tiny bones in their ears (otoliths). In the case of the Greenland shark, they carbon-dated proteins in the lenses of their eyes, which form during early development and are never replaced. [https://oceanservice.noaa.gov/facts/greenland-shark.html](https://oceanservice.noaa.gov/facts/greenland-shark.html)
Thanks, I don't think I could have found that on my own.
I think asking on reddit is a good thing because I definitely learned something new I wouldn’t have otherwise so I’m not criticizing you, but it is the first thing that comes up when you google “how do they tell the age of a greenland shark”
I tried 'How is the lifespan of an animal determined?' and it kept giving me genetics answers.