**Pangea** (sometimes spelled Pangaea) was a massive supercontinent that existed approximately **335 to 175 million years ago**. It assembled from earlier continental units during the late Paleozoic era and began to break apart during the early Mesozoic era.
The name, derived from Ancient Greek, literally translates to "all lands" (pan meaning "all" and Gaia meaning "Earth").
## Formation and Structure
Pangea was formed through a long process of plate tectonics, culminating when the Gondwana and Laurussia landmasses collided.
* **Shape:** It was roughly C-shaped, with the bulk of the land stretched across the equator.
* **The Tethys Ocean:** The "hollow" part of the C-shape was a massive gulf known as the Tethys Sea.
* **Panthalassa:** Surrounding this singular landmass was a global ocean called Panthalassa, which covered nearly the entire rest of the planet.
## The Breakup
The fragmentation of Pangea occurred in three major stages, driven by volcanic activity and seafloor spreading:
1. **Stage 1 (Middle Jurassic):** A rift formed between North America and Africa, creating the North Atlantic Ocean.
2. **Stage 2 (Early Cretaceous):** The southern landmass (Gondwana) fractured into South America, Africa, India, Antarctica, and Australia.
3. **Stage 3 (Early Cenozoic):** North America and Greenland finally separated from Eurasia, and the Southern Ocean began to open as Australia drifted north.
## Evidence for Pangea
When Alfred Wegener first proposed the theory of **Continental Drift** in 1912, he relied on several key pieces of evidence:
* **Continental Fit:** The most famous example is how the coastline of South America fits almost perfectly into the "notch" of western Africa.
* **Fossil Records:** Identical fossils of plants (like *Glossopteris*) and reptiles (like *Mesosaurus*) have been found on continents now separated by thousands of miles of ocean.
* **Geological Matches:** Mountain ranges in the eastern United States (Appalachians) match the age and structure of the Caledonian mountains in Scotland and Scandinavia.
* **Paleoclimatology:** Evidence of ancient glaciers has been found in tropical regions of India and Africa, suggesting those landmasses were once located near the South Pole.
## Impact on Life and Climate
Because Pangea was a single landmass, it had a profound impact on the Earth's environment:
* **Extreme Interiors:** The center of the continent was likely very arid and experienced extreme temperature swings, as it was far from the moderating influence of the ocean.
* **Biological Migration:** Terrestrial animals could migrate freely across the globe, leading to a period of relatively low biological diversity between different regions.
* **Ocean Currents:** The singular landmass redirected global ocean currents, which played a major role in the Earth's climate cycles during the Permian and Triassic periods.
