Now, it turns out they can do the same thing with another species of skilled tool users in the midst of their own "Stone Age" — sea otters. Haslam had studied the use of stone tools in monkeys and apes using archeological techniques, and proposed doing similar research on sea otters. Tinker said he was skeptical, since sea otters mostly use rocks that they collect in the bottom of the ocean. It may even be possible to get information about how sea otters' diets have evolved over time or how and when tool use evolved in sea otters, the researchers suggest. Sea otters leave the right side of the mussel shell broken and the left side unbroken.

Source: CBC News March 14, 2019 14:00 UTC