WEBVTT - How Did the Ancient Land Blob Called Gondwana Become Today's Southern Continents?

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<v Speaker 1>Welcome to brain Stuff production of iHeartRadio. Hey brain Stuff,

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<v Speaker 1>Lauren Vogel bomb here. Sometimes good science can happen just

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<v Speaker 1>by looking at a map of the world and letting

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<v Speaker 1>your mind wander. For instance, observe how Africa and South

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<v Speaker 1>America seem to have been very recently cuddled together, even

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<v Speaker 1>though there are currently a couple of thousand miles of

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<v Speaker 1>ocean between them. Similarly, Madagascar fits perfectly into a little

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<v Speaker 1>nick in the eastern edge of Africa, and the Middle

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<v Speaker 1>East seems to be pulling away from the top of

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<v Speaker 1>Africa like a corner being pulled off of a hot cookie.

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<v Speaker 1>With a reasonably good representation of the shape and arrangement

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<v Speaker 1>of the world's continents in front of them, anyone could

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<v Speaker 1>easily assess that the Earth's land masses have definitely been

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<v Speaker 1>sneaking around. The name for the southern land mass that

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<v Speaker 1>once was is Gondwana Land, also known as Gondwana. But

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<v Speaker 1>it wasn't just the shape of the continents that cluded

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<v Speaker 1>researchers into its former existence. They've also looked at similarities

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<v Speaker 1>among plants and animals that live across the modern separate continents.

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<v Speaker 1>From those clues, Gondwana was an idea long before anybody

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<v Speaker 1>figured out how or why it worked, the secret, of

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<v Speaker 1>course being plate tectonics, an idea that didn't really start

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<v Speaker 1>gaining steam until the mid twentieth century. But a nineteenth

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<v Speaker 1>century Austrian geologist named Edward Seuss put a name to

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<v Speaker 1>the concept of the supercontinent in his book The Face

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<v Speaker 1>of the Earth, the first volume of which was published

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<v Speaker 1>in eighteen eighty three. SEUs didn't come up with many

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<v Speaker 1>completely novel ideas, but he did a great job of

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<v Speaker 1>synthesizing a bunch of the research of the day to

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<v Speaker 1>conclude that the southern continents and land masses we now

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<v Speaker 1>know as South America, Africa, Arabia, India, Sri Lanka, and

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<v Speaker 1>Madagascar had at one point in time been connected because one, well,

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<v Speaker 1>just look at them, and two they contained the same

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<v Speaker 1>rocks and the same fossils from an extinct feathery leaked

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<v Speaker 1>tree called Glosso Terraces. Austria and Antarctico would be added

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<v Speaker 1>to the theory thirty years later. Gondwana was named for

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<v Speaker 1>a densely forested region of central India where the first

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<v Speaker 1>fossil evidence of the supercontinent was found. In the nineteenth century.

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<v Speaker 1>Juana is a word for forest in Sanskrit, and the

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<v Speaker 1>Gonds are tribe that European explorers first found living in

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<v Speaker 1>the region. Even though we now know a lot about

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<v Speaker 1>the mechanism by which Gondwana was formed, it's extremely complicated

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<v Speaker 1>and still being investigated. There's at least one peer reviewed

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<v Speaker 1>scientific journal devoted entirely to the study of the supercontinent.

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<v Speaker 1>It's called appropriately Gondwana Research. However, there are a few

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<v Speaker 1>things that were pretty certain of. First. Gondwana wasn't built

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<v Speaker 1>in a day. The making of Gondwana was a long process,

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<v Speaker 1>most likely through three major mountain building events driven by

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<v Speaker 1>the movement of Earth's tectonic plates. We spoke via email

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<v Speaker 1>with Joseph Merritt, a professor in the Department of Geological

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<v Speaker 1>Sciences at the University of Florida. He explained, during the

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<v Speaker 1>interval from about six dred and fifty two five hundred

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<v Speaker 1>and fifty million years ago, various pieces of Africa and

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<v Speaker 1>South America collided along an ancient mountain chain called the

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<v Speaker 1>Braziliano Belt, slightly older but overlapping with the Braziliano seven

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<v Speaker 1>fifty to six hundred and fifty million years ago, is

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<v Speaker 1>the East African Oregon or Mozambique Belt that resulted from

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<v Speaker 1>the collision between East Africa and Madagascar, India, Sri Lanka,

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<v Speaker 1>and parts of East Antarctica. The final collision was along

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<v Speaker 1>the Quanga Oregon between all those assembled pieces and the

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<v Speaker 1>rest of Antarctica and Australia between five hundred eighty and

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<v Speaker 1>five hundred thirty million years ago. So it was a

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<v Speaker 1>couple hundred million years of extremely slow continental car wrex

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<v Speaker 1>that created this beta version of Gondwana. But it wasn't

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<v Speaker 1>done yet. Later, about three hundred million years ago, other

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<v Speaker 1>land masses would join forces with it to form the

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<v Speaker 1>giant ball of land we now know as Pangaea. But

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<v Speaker 1>one continent to rule them all couldn't last, and sometime

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<v Speaker 1>between two hundred and eighty and two hundred million years ago,

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<v Speaker 1>panned has started disintegrating as magma began pushing up from

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<v Speaker 1>beneath this mega supercontinent, creating riffs in the land that

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<v Speaker 1>would later become sea floor. As Pangia cracked, the top

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<v Speaker 1>part was pushed to the north, creating the continent laur

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<v Speaker 1>Asia and Gondwana headed south back when Gondwana was just

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<v Speaker 1>a baby Supercontinent between five hundred and fifty and four

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<v Speaker 1>eighty five million years ago. It hosted some of the

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<v Speaker 1>very first complex life forms, like child bites and brachiopods,

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<v Speaker 1>but since it continued to exist into the Jurassic Period,

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<v Speaker 1>lots of plant and animal evolution went down there. Merritt said,

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<v Speaker 1>Gondwana contains evidence for evolutionary changes in the very first

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<v Speaker 1>complex animals, the very first fish, amphibians, and reptiles. The

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<v Speaker 1>most famous fossils are the Gondwana flora, such as the

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<v Speaker 1>glasso terrace fern, a freshwater reptile called Mesosaurus, and a

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<v Speaker 1>land reptile called Lystrosaurus. Gondwana existed as a single land

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<v Speaker 1>mass for more than three hundred million years because of

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<v Speaker 1>its Hu Monga's size, but it covered an area of

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<v Speaker 1>a hundred billion square kilometers or about thirty nine billion

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<v Speaker 1>square miles, and because the continents moved a lot during

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<v Speaker 1>that time, Gondwana experienced many different climates. Merit said. During

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<v Speaker 1>the Cambrian, when Gondwana first formed, the Earth and Gondwana

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<v Speaker 1>were in a greenhouse state. In the late Ordovician four

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<v Speaker 1>fifty billion years ago, Gondwana was moving over the South

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<v Speaker 1>Pole and the climate was very cold. Gondwana continued to

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<v Speaker 1>move through a variety of latitudes, and depending on where

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<v Speaker 1>you were located, the climate might have been quite warm

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<v Speaker 1>or more temperate. The continent was so large that one

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<v Speaker 1>part of Gondwana might be located at the equator while

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<v Speaker 1>another might be located at the pole. It's true it

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<v Speaker 1>would have been cool to see Gondwana in its prime,

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<v Speaker 1>and although you won't personally get to see its victorious return,

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<v Speaker 1>that doesn't mean that it's not possible. The continents are

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<v Speaker 1>always moving and scientists have a lot of ideas. But

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<v Speaker 1>what our next supercontinent is going to look like? H

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<v Speaker 1>Today's episode was written by Jesslyn Shields and produced by

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<v Speaker 1>Tyler Clang. Brain Stuff is production of I Heart Radios,

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<v Speaker 1>How Stuff Works. For one and this and lots of

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<v Speaker 1>other mega super topics, visit our home planet how stuff

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