Geological Time Scale – Structure of the Paleozoic How many named periods are included within the Paleozoic Era in standard geologic time charts used in earth science?

Introduction / Context:
The Paleozoic Era marks a transformative chapter in Earth history, including the Cambrian explosion of animal life and major steps in terrestrial colonization. Mastery of its internal period breakdown is foundational for stratigraphy and paleontology.

Given Data / Assumptions:

• We follow the widely accepted division of the Paleozoic.
• Count the formal periods recognized internationally.
• Focus on names rather than dates.

Concept / Approach:
The Paleozoic Era comprises six periods in order: Cambrian, Ordovician, Silurian, Devonian, Carboniferous, and Permian. Some regions historically split the Carboniferous into Mississippian and Pennsylvanian, but globally it is one period, keeping the total at six.

Step-by-Step Solution:
List periods sequentially: Cambrian → Ordovician → Silurian → Devonian → Carboniferous → Permian.Count them: 6.Confirm against alternative regional splits (do not double-count Carboniferous).

Verification / Alternative check:
Standard international stratigraphic charts and textbooks consistently enumerate six Paleozoic periods.

Why Other Options Are Wrong:

• four/five: undercounts; omits recognized periods.
• seven: overcounts; may be caused by splitting Carboniferous regionally into two.

Common Pitfalls:
Confusing regional terminology (Mississippian/Pennsylvanian) with global period counts. Remember: globally Carboniferous is a single period.

Final Answer:
six