Beginning of Essay
A long long time ago, in a galaxy not too far away, was a little blue planet called Earth, and on this world not a single mammal lived. However a lot of time has past since then and we now have lots of furry creatures that are collectively called mammals. How d ....

Middle of Essay
.... often covers a span of tens of millions of years. A lineage like this shows obvious intermediates for every major structural change, and the fossils occur roughly (but often not exactly) in the expected order. However, usually there are still gaps between each of the groups. Sometimes the individual specimens are not thought to be directly ancestral to the next-youngest fossils (e.g. they may be "cousins"" or "uncles" rather than "parents"). However they are assumed to be closely related to the actual ancestor, since the have similar intermediate characteristics. Where Does It All Begin ? Mammals were derived during the Triassic Period ((fr ....