2.3 New Zealand’s evidences for the Wegener Crater
1) Exotic flora and fauna of New Zealand
One of the mysteries that have always intrigued scientists is the specificity of the flora and fauna that live in the New Zealand archipelago.
Prior to the arrival of the first human inhabitants, there were no tetrapods in its territory — only birds, most of them non-flying ones.
The moas, distant relatives of African ostriches, lived until recently and reached up to 3.5 meters in height.
While still were small birds, moas’ ancestors came flying to the Islands and found a pristine environment totally free of predators.
Because they did not have to flee predators — not even egg-destroying rats and snakes — and fed with vegetation and insects without competitors to fight to, they lost their ability to fly and some species developed endemic gigantism.
Moas were extinct about 500 years ago by hunting promoted by the first human inhabitants and the mammals brought with them.
The Polynesian Maori arrived about 700 years ago and moas were a valuable and easy prey; 200 years later there was not a single moa roaming the Islands.
And this is the big puzzle:
If New Zealand split up from Gondwana and Australian continental bloc in relatively recent geological time — why did not any reptiles, amphibians, crocodilians, mammalian ancestors, or primitive mammals that then inhabited Australia come to live at the islands?
Why did none of these animals come along with the Islands with plenty conditions of sustainability?
This absence of competition with birds goes back to the genesis of the island.
There are no fossil records of any class of tetrapod animals, whether reptile, mammal or amphibian.
There are very few exceptions:
• Tuatara (Sphenodon spp.) is a reptile that lives only on small islets on the north coast of the two main Islands — they are no more present on mainland nowadays.
The tuatara descends from extremely primitive animals and no close relatives of it are found in the world — we will discuss its origins later.
Image: TUATARA, on Wikipedia. It looks like a lizard, but it is still more primitive, predating the dinosaurs.
• Frugivore bats also have arrived by flying. They successfully colonized the interior of the islands because they found an ecological niche not disputed by feathered competitors — and eventually lost their ability to fly for the same reasons as birds.
• Sea lions are limited to occupying ocean beaches — they have recently hunted penguins that had migrated from Antarctica.
• There is a single fossil record of a very small mammal, known by the provisional name “Saint Bathans mammal” that inhabited New Zealand between 16 and 19 million years ago.[1]
It probably arrived on the Islands wandering in floating vegetation rafts uprooted by floods, and developed a small local population — but failed to compete for space with birds fully adapted to their habitat.
3) New Zealand’s ferns and tuataras
Something paradoxical with New Zealand’s flora is their unusually high number of fern species.
Worldwide, ferns are mostly tropical plants — but New Zealand is a temperate country, and they have almost 200 species of ferns living there.
Astonishingly, about 40 per cent of New Zealander fern species are exclusively found on those islands.[4]
In fact the country is located on a latitude comparable to the south and Argentina and Chile, where climate is chilling for half of the year.
New Zealand ferns are adapted to low temperatures, while there are no ferns adapted to low temperatures in Australia... did they develop this adaptation only on the islands, or did they inherit it from remote times?
Image: Nature's Pic Images, Rob Suisted, https://www.naturespic.com/newzealand/image.asp?id=4504,
Stewart Island Ferns, New Zealand's third largest island
New Zealand ferns are adapted to low temperatures, while there are no ferns adapted to low temperatures in Australia... did they develop this adaptation only on the islands, or did they inherit it from remote times?
Perhaps the answer for that question, and the best proof of this hypothesis, will be provided by the island's only native tetrapod, the tuatara.
This animal is the last survivor of an order of animals that emerged shortly after the Permian Extinction — between 247.2 and 237 million years ago, and became very common between 200 and 220 million years ago — the Rhynchocephalia, also known as Sphenodontians.
All representatives of this order became extinct between 60 and 100 million years ago, except the tuatara.
And the supposed date of the break-up of New Zealand from the Australian continent is said to be about 100 million years ago — it is hardly credible that the last surviving sphenodons were at just the right time at the right place to migrate along with the Islands.
It is far more coherent to think that these animals were the first surviving vertebrates of the Permian cataclysm to colonize the North and South Islands while still united by land with West Antarctica.
Tuataras live in burrows, and this is a feature common to most survivors of large extinctions.
These reptiles are animals adapted to harsh conditions and, in the absence of beetles, do practice cannibalism — characteristics that allowed them to survive in extremely harsh environments like those post the great extinction.
But the main indicative of the Tuatara's Antarctic origin is its adaptation to cold climates.
Tuatara’s hemoglobin, unique in the world, allows them to be active at night with a minimum of light, and at temperatures up to 5 degrees above freezing, under conditions that would be fatal to most other reptiles.
And fundamentally, tuataras are animals that die at temperatures above 28°C.[5]
If they lived in Australia before migrating to New Zealand, these reptiles would hardly be able to develop adaptations like these.
Nor would they develop equally cold-adapted parasites such as the tuatara tick Amblyomma sphenodonti — these hematophagous insects, as primitive as tuataras, are not closely related to any other tick species, including those living in Australia.[6]
These ticks did not have origin on that continent, as otherwise their related offspring today would be parasitizing frilled-neck-lizards[7] — the tuataras’ parasites came from a time before the evolution of lizards.
Well, the answer to the riddle mentioned in a previous segment is simple:
New Zealand did not break up from Australia.
It separated from a much more distant location at the opposite side of Gondwana: West Antarctica.
Brief history:
The Islands have formed as a result of the impact that put an end to the Permian — they surfaced as magma cast from the depths into the outermost secondary ring of the Wegener Crater.
The fracture process of the Wegener Crater points to an initial break-up of the Philippine Sea Plate/Mariana Plate fraction up north, and the permanence of the Zealandia Plate attached to West Antarctica for at least a few tens of millions of years.
Meanwhile, East Antarctica was drifting westward and getting closer to the Wegener Crater remnants formed by Zealandia and West Antarctica plates — and later, probably before the Zealandia break-up, both halves of Antarctica would collide to form the Antarctica continent we know today.
With the fraction of the Philippine Sea Plate/Mariana Plate ever more distant, the winds carried the wind-borne spores from the relatively cold neighbouring continent only to the large peninsula formed by the fraction of Zealandia united to the West Antarctica fraction.
At that time, East Antarctica was a temperate landscape.
This is why the flora of the Islands is characterized by the presence of ferns and gymnosperms adapted to temperate climates — those primitive plants and trees dominated the Triassic period.
As soon as the weathering process disintegrated the crater’s newly formed rocks and provided conditions for the first pioneer plants to settle, insects arrived by flying or dragged by the wind.
Ants and cockroaches, resilient insects most likely to survive extinction events due to inhabiting burrows and crevices, were probably the first animals to colonize the Islands.
Only 11 native species of ants live in New Zealand, while in Australia there are more than 1,200 ant species, maybe twice this number.[2]
There are 4 native species from New Zealand, at least two of them totally adapted to cold climates: Celatoblatta quinquemaculata inhabits alpine regions of the islands, the black color of Maoriblatta novaeseelandiae is an adaptation for heat absorption, Parellipsidion latipenne has wings (but it rarely flies, at least nowadays), and finally the Parellipsidion conjunctum, quite different from other cockroaches around the planet.[3]
Image: Native insects Maoriblatta novaeseelandiae and Parellipsidion conjunctum adapted to cold weather https://inaturalist.nz/taxa/392119-Maoriblatta-novaeseelandiae and Taranaki Educational Resource: Research, Analysis and Information Network
There was no time for these extreme acclimation have been developed only after the supposed break up from Australia; even more, it is impossible that their lineage would have completely vanished, all of them disappearing from the continent.
It is worth mentioning that no one of these insects with ability to fly — ants and cockroaches — have got to reach the New Zealand Islands departing from Australia, even with help of the prevalent wind currents.
Wētās probably came in this first colonizing wave - it was a common animal in Gondwana.
Wētās probably came in this first colonizing wave - it was a common animal in Gondwana.
Although there are fossils of related animals in Australia, no Australian wētā have survived on the continent, another enigma of New Zealand fauna.
Before the New Zealand fraction split up from West Antarctica, there would have been time for early representatives of plant and animal life — Triassic lichens, pteridophytes and gymnosperms, insects, and tuataras — to colonize the pristine islands of New Zealand at the outer secondary ring.
But if so, then why don't we have the same plants and animals at Philippines, Taiwan or Japan?
In addition to the fact that cold acclimated species would not survive their passage through the high temperatures of the tropics, the Wegener Crater’s Philippine Sea Plate/Mariana Plate fraction separated from the Zealandia and Antarctica conjoined fractions soon after the impact.
The islands of the Philippine Sea Plate/Mariana Plate fraction only developed fertile land and created conditions for colonization when they were too far away into the Pacific Ocean to be reached by plants and animals.
The archipelagos and islands from the western outer secondary ring arrived in a totally pristine condition to Asia, and after have been drifting northwards for hundreds million years, their habitats were colonized by the modern representatives of the local Asian flora and fauna.
Going back to the fraction of the southern outer secondary ring/Zealandia:
Tens of millions of years after the impact, there was a definitive break-up from West Antarctica, and its tectonic plate drifted towards the Australian continent.
Over the time, new sedimentary terrain continued to develop through the natural processes of weathering of magmatic rocks.
New Zealand's habitats prospered, and as the Islands approached Australia and Indonesia, the conditions were ready to receive the addition of new and more modern inhabitants (angiosperms, new flying insects, birds, bats and sea lions).
What is the explanation for the development of exotic plants and animals adapted to cold and temperate climates exclusively in the New Zealand Islands, and not in the other islands of the outer secondary ring?
The answer is:
Because they developed on a cold, temperate continent, which Australia at that time was not.
New Zealand’s ferns and tuataras (along with their parasites), and also their native ants and cockroaches, came from Antarctica when the continent had a cold, but more friendly climate, while the crater was gaining its first vegetation layer.
This is the reason for the islands' exotic and unique flora and fauna.
New inhabitants arrived after the collision with Australia and Indonesia, fauna and flora have thrived, and the rest is history — and this brings an end to the puzzle that has confused scientists during the last 200 years.
4) Present theory for New Zealand's separation from Australia
Regarding the theory that New Zealand has split from its continental neighbour, the conclusion is obvious:
The separation of the subcontinental bloc of Zealandia from Gondwana, specifically from Australia, is not a conclusion based on factual, observable and verifiable facts...
This hypothesis represents only a rational reasoning designed to correspond to the expected logical explanation, forced to fit into the established school of scientific thought of an era, for lack of an acceptable — or even conceivable — alternative.
It is the explanation that scientists considered reasonable based on scientific foundations firmly established in the late 19th and mid 20th centuries, such as random mantle plumes and the then revolutionary theory of continental drift.
It is the explanation that scientists considered reasonable based on scientific foundations firmly established in the late 19th and mid 20th centuries, such as random mantle plumes and the then revolutionary theory of continental drift.
After all, at that old times asteroid impacts were a fantasy of delusional catastrophists, many of them forcing the boundaries of Science to attest millenary-old religious traditions opposed to the advance of scientific knowledge... it was the way of thinking in our past societies.
But we must acknowledge:
Most Geologists did work using the best information available at the time – and if it we could not take on the hard work of so many scientists who patiently investigated the Nature, often without anyone's support to publish their findings, we wouldn't go this far – the tools that allowed this study and discoveries were not publicly available until the beginning of this century.
[1] Fossil discovery turns scientific theory on its head, Trevor Worthy, School of Earth & Environmental Sciences, University of Adelaide
[2] Te Ara, The Encyclopedia of New Zealand, https://teara.govt.nz/en/ants/page-2
[3] T.E.R:R.A.I.N - Taranaki Educational Resource: Research, Analysis and Information Network, http://www.terrain.net.nz/friends-of-te-henui-group/local-insects/
[4] Department of Conservation, Te Papa Atawhai, Government of New Zealand, https://www.doc.govt.nz/nature/native-plants/ferns/
[5] Musico, Bruce (1999). "Sphenodon punctatus". Animal Diversity Web. University of Michigan, Museum of Zoology. 22 April 2006.
[6] Miller, Hilary C.; Conrad, Ailis M.; Barker, Stephen C.; Daugherty, Charles H. (January 2007). "Distribution and phylogenetic analyses of an endangered tick, Amblyomma sphenodonti". New Zealand Journal of Zoology. 34 (2): 97–105.
[7] Chlamydosaurus kingii. Australian reptile similar in size to the tuatara, but from the order Squamata, more modern than the Sphenodontia.
ATTENTION: Blog in reverse order. To continue reading, go to the post below ("Postagem mais antiga").
ATTENTION: Blog in reverse order. To continue reading, go to the post below ("Postagem mais antiga").
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