Skeletal muscles are CELLS formed by skeletal muscle tissue, and the tissue is made up of skeletal muscle ORGANS. Hope that helps :)
Humans are least likely to survive.
Answer:
Certain fossils, called index fossils, help geologists match rock layers. To be useful as an index fossil, a fossil must be widely distributed and represent a type of organism that existed for a brief time period. Index fossils are useful because they tell the relative ages of the rock layers in which they occur.
