Fossils have a lack of being very detailed due to not being able to preserve everything on the animal. This can be an issue because scientists then have to guess and/or use imagination to detail the rest of the animal. These things include, color, skin, eyes etc.
Flatworms are interesting because they have no kind of fossils. Over 4000 species of flatworms is in existence today. Humans have many common ancestors with a wide variety of animals. Chimpanzees are especially a close branch in the tree. Humans and chimpanzees have no fossil records though. This could due to the fact that chimpanzees and humans live only on land. What people think is that creatures that are not favored evolved from very dominant ones. This statement is the complete opposite of how evolution is. Animals in the sea are up for the next discussion. If you examine different the movement of two different animals in an ocean, you will find that they move around in vastly different ways. A long time ago, every living thing all lived in water together. It was the toughest of animals and plants to take the dare and move to land. Some of these animals remained to