The
Tethys Ocean was a
Mesozoic era
ocean that existed between the continents of
Gondwana and
Laurasia before the opening of the
Indian Ocean.
In 1893, using fossil records from the Alps and Africa, Eduard Suess proposed the theory that a shallow inland sea had once existed between Laurasia and Gondwana. He named it the 'Tethys Sea' after the Greek sea goddess Tethys. The theory of plate tectonics later disproved or overrode many parts of Suess's theory, even determining the existence of an earlier body of water called the Tethys Ocean. However, Suess's overall concept was still relatively accurate and remarkably imaginative for its day, so he generally is credited with the discovery of both the Tethys Sea and the Tethys Ocean.
About 250 million years ago,[1] during the Triassic, a new ocean began forming in the southern end of the Paleo-Tethys Ocean. A rift formed along the northern continental shelf of Southern Pangaea (Gondwana). Over the next 60 million years, that piece of shelf, known as Cimmeria, traveled north, pushing the floor of the Paleo-Tethys Ocean under the eastern end of Northern Pangaea (Laurasia). The Tethys Ocean formed between Cimmeria and Gondwana, directly over where the Paleo-Tethys used to be.
During the Jurassic Period (150 mya), Cimmeria finally collided with Laurasia. There it stalled, the ocean floor behind it buckling under, forming the Tethyan Trench. Water levels rose and the western Tethys came to shallowly cover significant portions of Europe. Around the same time, Laurasia and Gondwana began drifting apart, leaving the Atlantic Ocean between them. Between the Jurassic and the Cretaceous (100 mya), even Gondwana began breaking up, pushing Africa and India north, across the Tethys and opening up the Indian Ocean. As these land masses pushed in on it from all sides, up until as recently as the Late Miocene (15 mya), the Tethys ocean continued to shrink, becoming the Tethys Seaway or (second) 'Tethys Sea'.