The Earth is about 4.6 billion years old. The geological time scale divides up this vast time interval. This scale is most detailed for the time in which life was abundant, as shown by fossils.
4,600 - 540 Million years ago. Hadean Time.
~4,500 - Collision produced the moon.
3,800 - earliest life forms (Archaea) detected.
2,500 - Cells with Nucleus, followed by rise in atmospheric oxygen.
1,500 - Snowball earth.
Laurentia - the North American Craton formed 1.5 to 1.0 Bya.
The oldest fossils are between 3 billion and 3.5 billion years old. About 540 million years ago was the start of the Phanerozoic Eon. Phanerozoic means “visible life”- the time fossils became abundant.

Oceans with rapidly evolving plants and shelled animals covered most of proto- North America

Trilobites reached their maximum, primitive fish appeared.

Tectonic orogeny in east and northeast North America.

First Land Plants.

First Forests (Evergreen)

In North America the interval consists primarily of marine limestones,

During the Mississippian an important phase of orogeny occurred in the Appalachian Mountains.

All modern classes of fungi have been found in Pennsylvanian rocks.

Invertebrates: arthropods far larger than modern ones. Arthropleura, a giant millipede relative & the giant dragonfly Meganeura.

Vertebrates:Amphibians were diverse and common; some were several meters long as adults.

The collapse of the rainforest ecology in the mid-Pennsylvanian (between the Moscovian and the Kasimovian) removed many amphibian species that did not survive as well in the cooler, drier conditions.
Amniotes, however, prospered due to One of the greatest evolutionary innovations of the Carboniferous - the amniote egg, which allowed for the further exploitation of the land by tetrapods.

Subcontinent Pangaea became fully assembled.