Aromorphoses of the Paleozoic era. In plants and animals by periods.

The Cambrian period is characterized by a change in the skeleton in animals, as well as a more complex organization in general. The flora is inhabited by algae.
Ordovician is distinguished by the presence of a notochord in animals and a displacement of the circulatory and nervous systems. During this period, psilophytes arise.
The Silurian period boasts the appearance of arthropods and some invertebrates. Terrestrial plants appear for the first time.
Devonian period – a variety of marine fauna, amphibians appear for the first time.
Carboniferous period – the appearance of winged insects and the development of reptiles.
Permian period – new types of skin integuments appear.