The paleozoic era was the early development of plants, fish, and other organisms.
The feathery plant like organisms anchored themselves to the sea floor.
Jellyfish like organisms floated around the oceans. There were also other types of organisms.
There were squid, octopus, trilobites, and a bunch of other organisms.
The animals started to eveolve and they evolved into fish.
The reason I like the paleozoic era is because the animals and plants evolved. There were a lot of interesting animals and plants.