Sometimes good science can happen by just looking at a map of the world and letting your mind wander. For instance, observe how Africa and South America seem to have been very recently cuddled together, even though there are currently a couple thousand miles of ocean between them. Similarly, it doesn’t take a Ph.D. to see that Madagascar fits perfectly into a little nick in the eastern edge of Africa, or that the Middle East seems to be pulling away from the top of Africa, like a corner being pulled off a hot cookie. With a reasonably good representation of the shape and arrangement of the world’s continents in front of them, a third-grader could easily assess that the Earth’s land masses have definitely been sneaking around.
The answer to the mystery, in case you were wondering, is Gondwanaland, also known as Gondwana.
«The idea of Gondwana — the agglomeration of the southern continents — arose first from a rather simple observation of the excellent jigsaw fit between South America and Africa and the similarities between flora and fauna across the continents that make up Gondwana,» says Joseph Meert, a professor in the Department of Geological Sciences at the University of Florida, in an email interview.
Gondwana was an idea long before anybody figured out how or why it worked — the secret, of course, being plate tectonics, an idea that didn’t really start gaining steam until the mid-20th century. But a 19th-century Austrian geologist named Eduard Seuss put a name to the concept of the supercontinent in his book «The Face of the Earth,» the first volume of which was published in 1883. Seuss didn’t come up with many completely novel ideas, but he did a great job of synthesizing a bunch of the research of the day to conclude that the southern continents and landmasses we now know as South America, Africa, Arabia, India, Sri Lanka and Madagascar (Australia and Antarctica would be added to the theory 30 years later), had at one point in time been connected because (1.) well, just look at them and (2.) they contained the same rocks and the same fossils from an extinct, feathery-leafed tree called Glossopteris.
Even though we now know a lot about the mechanism by which Gondwana was formed, it’s extremely complicated — there’s at least one peer-reviewed scientific journal devoted to the study of the supercontinent. However, here’s what we’re pretty certain of:
Gondwana Wasn’t Built In a Day
The making of Gondwana was a long process, most likely through three major mountain building events driven by the movement of Earth’s tectonic plates.
«During the interval from about 650 to 550 million years ago, various pieces of Africa and South America collided along an ancient mountain chain called the Brasiliano Belt,» says Meert. «Slightly older, but overlapping with the Brasiliano — 750 to 650 million years ago — is the East African Orogen, or Mozambique Belt that resulted from the collision between East Africa and Madagascar, India, Sri Lanka and part of East Antarctica. The final collision was along the Kuunga Orogen between all those assembled pieces and the rest of Antarctica and Australia between 580 and 530 million years ago.»
So, it was a couple hundred million years of extremely slow continental car wrecks that created this beta version of Gondwana — later, about 300 million years ago, other land masses would join forces with it to form the giant ball of land we now know as Pangea.
But one continent to rule them all couldn’t last, and sometime between 280 and 200 million years ago, Pangea started disintegrating as magma began pushing up from beneath the mega-supercontinent, creating rifts in the land that would later become sea floor. As Pangea cracked, the top part was pushed to the north, creating the continent called Laurasia, and Gondwana headed south, and eventually divided into the continents we know and love today.
Life On Gondwana
When Gondwana was just a baby supercontinent between 550 and 485 million years ago, it hosted some of the very first complex life forms like trilobites and brachiopods. But since it continued to exist into the Jurassic Period, lots of plant and animal evolution went down there.
Jurassic world. Low cloud in a Gondwana Rainforest makes for this lost in time world where dinosaurs once roamed. These rainforest are scattered along the east if Australia, mostly in the northern N.S.W. and south east QLD. @Nikon_Australia #Australia #landscapephotography
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«Gondwana contains evidence for evolutionary changes in the very first complex animals, the very first fish, amphibians and reptiles,» says Meert. «The most famous fossils are the Gondwana flora such as the Glossopteris fern, a freshwater reptile called Mesosaurus, and a land reptile called Lystrosaurus.
The Climate of Gondwana
Gondwana existed as a single landmass for more than 300 million years. Because of its humongous size — it covered an area of 39,000,000 square miles (100,000,000 square kilometers) — and because the continents moved a lot during that time, Gondwana experienced many different climates.
«During the Cambrian when Gondwana first formed, the Earth and Gondwana was in a greenhouse state,» says Meert. «In the late Ordovician (450 million years ago) Gondwana was moving over the South Pole and the climate was very cold. Gondwana continued to move through a variety of latitudes and depending on where you were located, the climate might have been quite warm or more temperate. The continent was so large that one part of Gondwana might be located at the equator whilst another might be located at the pole!»
It’s true — it would have been cool to see Gondwana in its prime, and although you won’t personally get to see its victorious return that doesn’t mean it’s not possible. The continents are always moving, and scientists have a lot of ideas about what our next supercontinent is going to look like.