Panthalassa

The Snider-Pellegrini-Wegener fossil map which illustrates how scientists pieced Pangaea together

During the Permian era (around 300 million years ago) the strange slow dance of Earth’s tectonic plates brought together all the world’s major landmasses into the supercontinent Pangaea.  Because of its very nature, Pangaea changed the world’s climate in bizarre ways.  Baking hot deserts were so far from the coast that they never received rain.  Landlocked seas boiled away and left great evaporitic deposits of strange minerals which we still mine and exploit.  Huge mountains rose and fell as the continents crashed together.

Pangaea lasted for approximately 100 million years, during a time of tremendous biological upheaval and diversification.  The worst mass extinction in the history of life took place during the continent’s heyday (The Permian-Triassic extinction event took place about 250 million years ago).  After the great dying, he first dinosaurs and mammals walked the super continent.  However this post is not a meditation concerning Pangaea (thankfully– since its history is extraordinarily complicated).

Triassic Pangaea by Richard Morden

The idea which excites me is that Pangaea was only a third of the Earth.  The remainder of the globe was taken up by water.  Between Laurasia and Gondwana there was a great wedge shaped ocean called the Tethys Ocean (indeed Pangaea looked somewhat like Pacman—as you can see on the beautifully illustrated map by Australian freelance illustrator Richard Morden).  Named after a titaness who was the daughter of Uranus and Gaia, the Tethys radically changed shape as the continents separated.  Through big parts of its history, large parts of the Tethys consisted of warm shallow continental shelves (which are ideal environments for fossil deposits).  Paleontologists and Geologists thus know a great deal about the natural history of the Tethys Ocean.

The remainder of the globe was a single world ocean called Panthalassa (or the Panthalassic Ocean).  If you looked at Earth from outer space from a particular angle it would have been entirely blue (which is fitting for “Panthalassa” was not named after any god or goddess but from a Greek neologism meaning “universal sea”).  The Panthalassa is not so well known as the Tethys.  As Pangaea broke apart almost the entire ocean floor was subducted underneath the North American and Eurasian plates.  However Geologists sometimes find tiny distorted remnants which were one part of the gigantic world sea.

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