Tethys Ocean

Tethys Ocean
Tethys Ocean as it appears in the third segment of Oceans
Location
Supercontinent	Gondwanaland
Continent	Europe
Temporal Range	250 - 5 million years ago, Induan - Zanclean Stage, Early Triassic - Early Neogene Period
Episodes	Coasts (Segment 4) Islands (Segment 1) Oceans (Segments 3 and 5)
Filmed In	Hațeg Island Noah Creek, Daintree Rainforest, Queensland, Australia (Islands, Segment 1) Ibero-Armorican Island Porto Santo Island, Madeira, Portugal (Oceans, Segment 3) Deep Sea Es Freus Marine Reserve, Ibiza, Spain (Oceans, Segment 5)
Characteristics
Environment	Open Sea
Notable Areas	Hațeg Island, Romania Ibero-Armorican Island Liburnia Formation, Trieste, Italy

The Tethys Ocean (also called the Tethys Sea or the Neo-Tethys), named after the ancient Greek titan of the sea (sister and wife of Oceanus, titan of the oceans), was an ocean that covered most of Europe for the entire Mesozoic Era, up until the Pliocene Epoch of the Cenozoic Era, when its last remnant, the Paratethys (which was isolated from the main Tethys Ocean during the Late Jurassic Period), dried up.

Paleoenvironment

“ In southern Europe, where the Atlantic meets the great Tethys Sea, coastal life perhaps reaches its greatest diversity. Rising sea level means that there are countless submerged islands covered with sponges, clams, and corals. Corals take advantage of the sunshine in these shallows, forming partnerships with algae that grow within their tissues. They collect tiny particles of food floating in the ocean currents. Myriads of these marine creatures encrust the solid rock. But one rock here appears surprisingly bare. Beyond is a sheer drop-off and the deep sea, home to oceanic predators, and danger for unwary reef fish. ”

― David Attenborough, Coasts

The Tethys Ocean harbors rich ecosystems of marine life, from massive mosasaurs, plesiosaurs, and sharks to thousands of species of ammonites, bivalves, and types of fish both living and extinct, like pycnodonts. However, the presence of the Tethys Ocean also affected diversity for those on land. For most of the Mesozoic Era, the majority of Europe (most especially central Europe, which was a part of the supercontinent of Gondwanaland) was scattered, rendered as a series of small islands and archipelagos. This isolation allowed the animals of Europe to evolve mostly undisturbed by the inhabitants of other continents, and therefore diversify and assume unique roles. Given the conditions of life on islands, where resources are limited due to the smaller area, some animals were subjected to insular dwarfism, growing smaller than their mainland cousins in order to lessen the amount of their body requirements, while others, taking advantage of this and niches left unoccupied by creatures not present on the islands, take control of their ecosystems via insular gigantism.

Appearances

The Tethys Ocean serves as the setting of the fourth segment of Coasts, where a Mosasaurus relaxes in a cleaning station before being forced to defend his territory from a younger male. It briefly appears in the seventh segment of Forests, which is mostly set by the Hațeg Island, with a male Hatzegopteryx visiting the island's beaches (where the island's other inhabitants lick sea salt from the coastal plants or initiate courtship) before flying across the ocean to go elsewhere. The Tethys Ocean next appears as the first segment of Islands, which involves a Zalmoxes rafting across the sea (encountering dangers like a Prognathodon in the process), meeting another of his kind on his mysterious and accidental journey to new lands. The Tethys Ocean is also the setting of the third segment of Oceans, which shows newborn Nostoceras getting stranded on the shores of the Ibero-Armorican Island before escaping back into the sea. The fifth segment of that same episode reveals that the surviving Nostoceras ended up in the sea grass beds of the Tethys Ocean, an ideal place to live for several species of ammonites.

Paleofauna

Baculites sp.

Diplomoceras maximum

Mosasaurus hoffmannii

Nostoceras sp.

Prognathodon saturator

Pycnodont

Sphenodiscus sp.