What is the most significant difference between Precambrian and Paleozoic life-forms?

The Precambrian life forms were less developed than the Paleozoic life forms. The Precambrian life forms were just starting to develop because this was 544 million years ago. that meant that things still needed to grow. This time didn't last very long though, due to the morphic and erosional processes. The Paleozoic Era began when organisms began developing new hard parts. This made it easier for fossils to be preserved.