Tethys Ocean

Tethys Ocean as it appears in the third segment of Oceans

### 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

### 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.

## Description

***“ 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.

### Hațeg Island

*Main: Hațeg Island*

Main: Hațeg Island

***“ Even by day, it's still dark in the understory of the dense forests, such as this one in Europe. Animals of any kind are difficult to distinguish. Yet, they're everywhere. ”***

― **David Attenborough**, *Forests*
Hațeg Island (modern-day Hunedoara County, Romania) is one of the most-known islands in the Tethys Ocean. It is approximately 200 kilometers (120 miles) away from the nearest landmass, and it has a total area of around 80,000 square kilometers (31,000 square miles). Since most of the inhabitants of the island are small (some because they were always that small, as opposed to having been shrunken by insular dwarfism), Hațeg Island ended up producing one of the best-known examples of insular gigantism in nature. The plentiful amount of small creatures to prey on, coupled with the absence of other large predators, allowed the azhdarchid *Hatzegopteryx* to evolve into a form more heavily-built than its relatives, adaptations for it to assume the role of apex predator in its region, and possibly other islands within flying distance.

### Ibero-Armorican Island

***“ Danger in the ocean doesn't only come from deadly hunters. It could come from the sea itself. Here, around the islands of prehistoric Europe, it's the power of the tide that creates challenges for life, especially for the tiniest creatures. ”***

― **David Attenborough**, *Oceans*
The Ibero-Armorican Island was a Late Cretaceous landmass that encompasses most of southern France and northeastern Spain. The segment it appeared in (specified as taking place in the "La Bouchard Locality" in the Arc Basin of Provence-Alpes-Côte d'Azur, France) was shot on Porto Santo Island near Madeira, Portugal.

### Liburnia Formation

***“ The longer an island has been isolated, the more different its animal inhabitants may become. ”***

― **David Attenborough**, *Islands*
The Liburnia Formation of Trieste, Italy, is a tropical carbonate island full of conifers and gymnosperms, surrounded by large forests. Originally mistaken as a Maastrichtian formation around 70 million years old, later studies (made too late for the show to adjust to) revealed that it was a Campanian formation around 80 - 81.5 million years old.

## 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.

## Fauna

*Baculites sp.**Diplomoceras maximum**Mosasaurus hoffmannii**Nostoceras sp.**Prognathodon saturator*Pycnodont*Sphenodiscus sp.*
## References

1. ↑ I Know Dino: The Big Dinosaur Podcast, Episode 443: Dinosaurs on Islands. Featuring Prehistoric Planet 2
2. ↑ 2.0 2.1 2.2 I Know Dino: The Big Dinosaur Podcast, Episode 446: Dinosaur-era Oceans and Darren Naish from Prehistoric Planet 2
3. ↑ The Gondwana supercontinent after amalgamation of West and East Gondwana resulting from the formation of the East African orogen.
4. ↑ Naish, Darren (@TetZoo) (June 17, 2023) on Twitter, regarding the capability of *Hatzegopteryx* to fly from Romania to Italy and remains of similar azhdarchids across Europe
5. ↑ Naish, Darren (@TetZoo) (June 18, 2023) on Twitter, discussing how *Tethyshadros* lived in a tropical carbonate platform environment that was dominated by gymnosperms and conifers
6. ↑ An Italian dinosaur Lagerstätte reveals the tempo and mode of hadrosauriform body size evolution
7. ↑ Naish, Darren (@TetZoo) (June 18, 2023) on Twitter, discussing how *Tethyshadros* did not come from the Maastrichtian, but instead from the Campanian Stage of the Late Cretaceous Period.