The archeology of the sea otter reveals the most shattering rocks | Science


By Alex Fox

Sea otters – the only known marine mammal to use stone tools – eat on the run by cracking mussels, sea urchins and abalone with rocks, using their hairy breasts as anvils. Now, a new study shows that by borrowing archeology techniques, marine biologists can select otter "utensils" in other rocks.

Many primates also use stone tools. Recently, researchers have combined biology and archeology to identify the wear patterns of such tools used by monkeys and apes, some dating back 700 years. The results obtained by the researchers question whether such methods could also be used on sea otters.

Many sea otter rocks are thrown to the bottom of the sea, but some are found on beaches, where otters hit their shelled prey against rocks emerging from the sea. Bennett Slough, an estuary in central California, offers researchers have an opportunity to examine the feeding behavior of otters – as well as the rocks they left behind after breaking dinner.

After 10 years of observations, the team identified an "otter signature". Rocks used as tools had tips and ridges lighter in color than the rest of the rock. The researchers then examined an additional 421 rocks in the area and found that 77 of them were used to break up shellfish, they reported today. Scientific reports. Broken mussel shells littering the nearby rocks corroborated the results, showing revealing breaks corresponding to the otter contour force mode of operation.

With their distinctive patterns, the stones could tell scientists when sea otters started using tools. The researchers say that understanding how long this behavior has existed and how it is spreading among populations could also help shed light on the more general issue of the evolution of tool use at D & O. Other mammals, including humans.

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