The Carboniferous period from 354 to 290 million years ago brought us most of the coal we use today. The planet is again experiencing global warming, the equator areas are warmer, poles still have ice. Continents are colliding towards our single continent of Pangea. Oceans rise and fall with the climate changes.
Huge tropical forests begin to spread across the land. These trees grew so fast they sucked vast quantities of CO2 out of the air. Oxygen rises to 35% of the atmosphere ( it’s only 21% today ).
Club mosses form giant trees 160′ tall. Tree ferns grow to 26′ tall. The world is humid and all the giant plant life makes it a shady planet.
Giant insects abound, we have spiders with leg spans of 20″ across. There are dragon flies with 26″ wingspans. Some centipedes are 6′ long! Scorpions reach 3′. The world is no longer silent but only plants rustling and insects can be heard. Warm blooded creatures are just arriving on the scene.
Forests are vast and spread from one end of the land to the other on warm areas. Falling, decaying plants build up huge layers of peat that will later become coal.
Everything is still green at the beginning. Flowers are just beginning to appear. Aerial roots are common on plants.
Spores differentiate in size and function based on sex. Seeds are now retained in the plant for germination.
Seed ferns are gone when this era closes, but cycads, conifers, and ginkgoes all appear and remain with us today.
The world cools as this era ends, and everything shrinks in size.