Uplifting near the end of the Mississippian resulted in increased erosion, with an increase in the number of floodplains and deltas.
The deltaic environment supported fewer corals, crinoids, blastoids, cryozoans, and bryzoans, which were abundant earlier in the Carboniferous.
Plant material did not decay when the seas covered them, and pressure and heat eventually built up over millions of years to transform the plant material to coal.
The beginning of the Carboniferous generally had a more uniform, tropical, and humid climate than exists today. These observations are based on comparisons between fossil and modern-day plant morphology.
The North American Pennsylvanian environment was alternately terrestrial and marine, with the transgression and regression of the seas caused by glaciation.
A further collision of Siberia and eastern Europe created the Ural Mountains of Russia.These stages are (from early to late) Tournaisian, Visean, and Serpukhovian for the Mississippian and Bashkirian, Moscovian, Kasimovian, and Gzhelian for the Pennsylvanian.