What do you notice about the complexity of the fossils as we move through the geologic time scale from the Precambrian times to quaternary period?

Comparing the fossils through the geologic time scale, starting with the Precambrian and going towards the Quaternary, we can see that the fossils of the animals and the plants have gradually been becoming more and more complex.

While in the Precambrian period the living organisms have been relatively simple, most of the animals being covered with exoskeletons, living in water, the diversification much smaller, and the plants still being very primitive, in the periods that follow there's great changes. The plants become bigger and more complex, developing new way of life, while the animals develop bone structures inside their bodies. The diversification explodes. The living organisms grow in size, develop special and unique features, live in pretty much every environment.