Tahora Formation

Tahora Formation
The Tahora Formation as it appears in the sixth segment of Coasts
Location
Supercontinent	Gondwanaland
Continent	Zealandia
Country	New Zealand
Unit of	Tinui Group
Region	North Island Gisborne City Napier City
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
Environment	Open Sea, Sunken Continent
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.

Paleoenvironment

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.

Paleofauna

Kaikaifilu hervei (possible substitute for Moanasaurus mangahouangae)

Mosasaurus hoffmannii

Tuarangisaurus keyesi