Answer:
The Cattle Egret follows cattle and eats the insects stirred up by the cattle. They are not benefiting each other or harming each other.
Can you provide a picture of the graph?
Answer:
There are two ways
1) By the depth at which the fossil was found(i.e. If it was found near the surface of Earth, then its a fossil which was just recently decomposed, but if it was deep inside then it's old.
2) By method of Carbon Dating