This situation does not mean that the sixty-year-old is dead.

The beetle is a type of crustacean. When the beetle opens its mouth, it is usually to spit out sand or other impurities.

Opening the mouth of a sixtieth beetle does not necessarily mean that it is dead, because some sixtieth beetles will also open their mouths while alive. Unless you can see that the flesh of the turtle is shrunken and rotten, it is dead.