The concept of Pangea fundamentally reshaped our understanding of Earth’s geology, moving the scientific community away from a static view of the planet. Pangea, meaning “all lands,” describes the ancient supercontinent that incorporated nearly all of the planet’s landmasses into a single contiguous body. This massive configuration assembled near the end of the Paleozoic Era, approximately 335 million years ago. It persisted until it began to fragment around 175 million years ago in the mid-Mesozoic Era. Its existence confirms that Earth’s crust is not fixed but is instead a dynamic surface composed of tectonic plates in constant, slow motion, a process that continues to reshape the continents today.
The Proposal and Initial Evidence
The formal proposal for a single ancient landmass originated with German meteorologist Alfred Wegener in 1912, forming the foundation of his theory of Continental Drift. Wegener’s hypothesis was initially met with skepticism, but it was supported by physical and biological evidence. The most striking evidence was the geometric fit of the continental coastlines, particularly the eastern edge of South America and the western edge of Africa. Further refinement of this “jigsaw puzzle” fit showed that the continental shelves, rather than the visible coastlines, matched even more precisely.
Fossil distribution showed that landmasses now separated by vast oceans were once connected. For example, the fossilized remains of the small freshwater reptile Mesosaurus are found only in specific regions of Brazil and West Africa. Since this animal was a poor swimmer, it could not have crossed the Atlantic Ocean, implying a continuous habitat. Similarly, fossils of the land-dwelling therapsid Lystrosaurus have been discovered across South Africa, India, and Antarctica, continents currently in disparate climate zones.
Plant fossils, such as the seed fern Glossopteris, whose heavy seeds prevented long-distance dispersal, also supported this connection. Fossils of this plant are found across all the southern continents, including Australia, India, and South America. Finally, matching geological structures provided a physical link. The ancient Appalachian Mountains in the eastern United States align with the Caledonian and Hercynian mountain ranges found in Greenland, Ireland, Great Britain, and Norway. These systems are remnants of a single, continuous mountain range formed during the continent-building collisions that created Pangea.
Formation and Breakup Timeline
The assembly of Pangea culminated in the Permian Period, a geological event known as the Alleghenian orogeny. The supercontinent was bounded by the superocean Panthalassa. Its breakup was driven by the mechanics of plate tectonics, where mantle convection currents created zones of weakness. These zones caused the supercontinent to stretch and rift, leading to the creation of new ocean basins.
Fragmentation occurred in distinct phases starting in the Early Jurassic Period, around 200 to 175 million years ago. The first phase involved rifting between the northern landmass, Laurasia (North America and Eurasia), and the southern landmass, Gondwana (Africa, South America, India, Australia, and Antarctica). This split began with volcanism and led to the opening of the Central Atlantic Ocean.
The second phase commenced in the Early Cretaceous Period (150 to 140 million years ago), focusing on Gondwana’s disintegration. South America and Africa separated, forming the South Atlantic Ocean. India, Australia, and Antarctica simultaneously began to peel away. The third phase, which continues today, involved the final separation and rotation of continents, such as India’s northward drift and collision with Asia, forming the Himalayas.
Life and Climate During Pangea
Pangea created a unique global environment that affected life and climate. With no major oceanic barriers, terrestrial species could migrate across the entire supercontinent, resulting in less regional species diversity. This connectivity is evident in the broad distribution of early terrestrial vertebrates and plant species.
The defining feature of the Pangean environment was its extreme continental climate. The interior was far removed from oceanic moisture, creating a “megamonsoon” circulation pattern characterized by extreme seasonal shifts in wind and precipitation. The supercontinent’s interior, especially during the Triassic Period, was dominated by vast, arid deserts.
Evidence from evaporite deposits and eolian sandstones, such as those found in the Colorado Plateau, suggest these interior regions experienced extreme temperature variations, including scorching days and frigid nights. Coastal regions, conversely, experienced heavy seasonal rainfall from the monsoons. This period of unified land and extreme climate followed the Permian-Triassic extinction, enabling the rise of new dominant forms, including the archosaurs, which diversified into the first dinosaurs.
The Next Supercontinent
The present continental configuration is only a temporary stage in Earth’s geological history. Continents continue to drift and collide in a process known as the Supercontinent Cycle, or Wilson Cycle, which describes the periodic opening and closing of ocean basins. The Atlantic Ocean is currently expanding as the Americas move westward, but it will eventually stop widening and begin to close as subduction zones form along its margins.
Based on current plate motion, scientists project that the next supercontinent will form in approximately 200 to 250 million years. Two main scenarios are proposed for this future configuration. The first, Pangea Proxima, suggests the Atlantic Ocean will close, pulling the Americas back toward Africa and Eurasia, with the collision centered near the equator. The second scenario, Amasia, projects the closure of the Arctic Ocean, resulting in a supercontinent formed around the North Pole as the Americas collide with Eurasia. The formation of this future landmass will alter global climate and ecosystems, continuing the cycle of planetary change initiated by Pangea.