These fossils are very useful for us because we can use them to date the layers of rock that they are found in. Fossils that can be used in this way are called index fossils, and rock layers with the same index fossils in them can be correlated. Not my answer, link here for full
http://peter-mulroy.squarespace.com/correlating-rock-layers/
The brown paper test for lipids is positive when food is placed on the paper and a spot forms that will allow light to pass through it. Which food would give the strongest positive test for lipids? The answer is The brown paper test for lipids is positive when food is placed on the paper and a spot forms that will allow light to pass through it. Which food would give the strongest positive test for lipids? The answer is Potato chips