Earth didn’t always look like it does today. At some point, all the land on Earth was one giant continent. Scientists call this supercontinent Pangaea.
These are the continents today, but they didn’t always look this way!
How do we know Pangaea existed?
Take a look at the picture of the continents above. You might notice some coincidences in the shape of the continents. The east coast of South America seems to fit like a puzzle piece into the west coast of Africa. If you rotate North America, it fits next to Europe and Asia.
Millions of years ago, these continents actually were all connected! They were all part of the supercontinent Pangaea. This supercontinent existed over 200 million years ago. It then very slowly broke apart into the continents we know today.
Pangaea was one large continent that was shaped a bit like a “C”.
Besides seeing that the continents fit together, how do geologists know that this supercontinent existed? Those observations have led geologists to look for more evidence of the supercontinent. Fossils show that the same organisms lived on the east coast of South America and the west coast of Africa. Geologists also found matching fossils on the coasts of North America and Europe. Landforms on today’s continents also provide evidence for Pangaea. The Appalachian mountains in North America line up with mountain ranges in Europe. A polar ice cap that covered the south of the supercontinent left deposits on several of today’s continents.
Plant and animal fossils are evidence that Pangaea existed.
The types of rock found across continents also show that Pangaea existed. The same type of coal, a sedimentary rock, is found in Pennsylvania and Europe. Igneous and sedimentary rock also sometimes contain magnetic components. These magnetic rocks point north when they form.
Geologists have found magnetic rocks that formed when Pangaea existed. The direction the magnets point lets them figure out where on Earth the rocks were when they formed! Then they can figure out how the continents have moved over time.
How did Pangaea form?
Pangaea formed between 270 million and 300 million years ago. Two smaller continents, called Laurussia and Gondwana, crashed into each other. This crashing occurred slowly, but it was not a gentle process. These collisions formed the Appalachian Mountains in North America and the Ural Mountains in Russia. That’s right – the continents smashed together hard enough to form mountains! The theory that explains how the continents crashed together is called continental drift. The continents are part of Earth’s crust, the outer surface of the Earth. The crust is not one big layer. The crust and the upper mantle are broken up into pieces, called plates. The plate boundaries are always changing. This makes the plates, and the continents, move over time!
What lived on Pangaea?
Because all the land was in one big mass, the climate of Pangaea was likely drier and hotter than it is now. The supercontinent sprawled across the equator and extended from the North Pole to the South Pole. If you lived at the time of Pangaea, you could walk from the North Pole to the South Pole without crossing an ocean.
The Batrachotomus dinosaur lived on Pangaea in the Triassic period.
But humans weren’t around yet when Pangaea existed. The supercontinent existed during the Triassic period. During this time, the first mammals and dinosaurs evolved.
What happened to Pangaea?
Over time, Earth’s plates continued to move. They eventually moved so much that Pangaea broke apart. As the continents moved far enough apart, the water from the ocean flowed in to fill up space.
Continental drift caused Pangaea to break up into today’s continents.
This process happened slowly. The plates only move up to 100mm (3.9 inches) per year. The continents didn’t reach their current arrangement until 35 million years ago. India crashed into Asia, forming the Himalayan Mountains. The animation below shows what this might have looked like.
Other Great Resources
Pangaea and the History of the Continents: