Tahora Formation

The Tahora Formation as it appears in the sixth segment of Coasts

### Temporal Range

85.8 - 66 million years ago, Santonian - Maastrichtian Stage, Late Cretaceous Period

### Episodes

* Coasts (Segments 3 and 6)
* Oceans (Segment 4)

### Filmed In

* Mealt Falls, Isle of Skye, Scotland (Coasts, Segment 3)
* A reef by Grand Cayman Island (Oceans, Segment 4)
* Underwater studio (Oceans, Segment 4)

## Characteristics

### Notable Areas

* Houpapa Member
* Maungataniwha Sandstone Member
* Mutuera Member

The **Tahora Formation** is a geological formation that is part of what is now Napier, New Zealand, approximately 85.8 - 66 million years old. It is named after the Tahora Station, south of Matawai in the Gisborne Region.

## Description

The Tahora Formation is part of the lost world of Zealandia, also known as "Tasmantis" or "Te Riu-a-Māui" (which means "the hills, valleys, and plains of Māui" in the Māori language). This sunken landmass is around one billion years old (evidence that it is indeed a continent in its own right and not simply a continental fragment or microcontinent), with a total area of approximately 4.9 million square kilometers (1.9 million square miles), six times the size of Madagascar and more than half the area of the neighboring Australian continent. Around 83 - 79 million years ago, Zealandia broke away from the rest of Gondwanaland, gradually sinking as it drifted further away. Around 23 million years ago, 94% of the landmass was completely submerged beneath the Pacific Ocean, with only New Zealand, New Caledonia, and a few of Zealandia's most elevated areas remaining above sea level, comprising a total of approximately 286,660.25 square kilometers (110,680.14 square miles), including all inland bodies of water.

During the Late Cretaceous Period, more parts of Zealandia would have still remained above the surrounding waters, forming an island sanctuary for various pterosaurs, theropods, titanosaurs, ornithopods, and even nodosaurids, as well as some beetles. Nevertheless, most portions of Zealandia were already submerged by that time, hence, the Tahora Formation (most especially the Maungataniwha Sandstone Member, which has a name that means "mountain of monsters" in the Māori language) serves as a rich fossil site full of ammonites, belemnites (squid-like cephalopods with an internal skeleton), crustaceans, gastropods, fish, rays like *Australopristis*, and plesiosaurs like *Tuarangisaurus* and the dubious *Mauisaurus*. The cosmopolitan 15-meter (50-foot) *Mosasaurus* and its 12-meter (40-foot) relative *Moanasaurus* would have been the top predators of the region. Zealandia would have also likely been visited by animals from other regions of the far south, as proven in the sixth segment of Coasts when the area was visited by the 10-meter (33-foot) mosasaur *Kaikaifilu*, which hails from the López de Bertodano Formation of Antarctica. Conversely, some of Zealandia's inhabitants may have also visited other southern regions, as indicated by isolated *Moanasaurus* teeth found in the López de Bertodano Formation.

## Appearances

***“ Back in the shallow waters of Zealandia, large groups of Tuarangisaurs have come together. They propel themselves with all four fins, and travel almost effortlessly to find the fish shoals that gather here in summer. ”***

― **David Attenborough**, *Coasts*
The Tahora Formation serves as the setting of the third and sixth segments of Coasts, the former featuring *Tuarangisauruses* seeking out gastroliths, pebbles smoothened out by a coastal waterfall, and the latter featuring a pod of them protecting a pregnant member of theirs from a *Kaikaifilu*.

***“ ... the very heart of the Pacific Ocean. These enormous atolls and the lagoons at their center provide the only shelter for thousands of miles. In this rare place, Tuarangisaurus, a kind of elasmosaur, finds safety. ”***

― **David Attenborough**, *Oceans*
Atolls near the area likely serve as the setting of the fourth segment of Oceans, where a *Mosasaurus* ambushes a pod of *Tuarangisaurus* as they leave their sanctuary to feed, eventually succeeding in catching one of the elasmosaurs.

## Fauna

*Kaikaifilu hervei* (possible substitute for *Moanasaurus mangahouangae*)*Mosasaurus hoffmannii**Tuarangisaurus keyesi*
## References

1. ↑ 1.0 1.1 I Know Dino: The Big Dinosaur Podcast, Episode 446: Dinosaur-era Oceans and Darren Naish from Prehistoric Planet 2
2. ↑ A fragment of a mysterious 8th continent is hiding under New Zealand — and it's twice as old as scientists thought
3. ↑ Zealandia: Earth's Hidden Continent
4. ↑ Gurnis, M., Hall, C.E., and Lavier, L.L., 2004, Evolving force balance during incipient subduction: Geochemistry, Geophysics, Geosystems, v. 5, Q07001