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0:10
the seven continents. When side by side, they emulate the pieces of a great geological jigsaw which were once assembled as a single sprawling superc continent known as Pangier. You might have heard of Pangier. For over a 100 million years, it was the dominant land structure on Earth. Home to giant reptiles and the ancestors of dinosaurs alike. But what is often less talked about is what came before. Our planet's contemporary continental chunks have been smashing
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together and separating for over 4 billion years. And there have been more than a few superc continents during that time. And it is those lost lands that take the stage in this video as we wind the clock back billions of years from the seven continents we know so well today to the creation of the very first land and how it evolved into the early supercontinents long before Pangier. [Music] A superc continent is a land mass that joins more than 75% of the available
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terrain on Earth. The closest thing we have today is the Afroureasian mega continent, which bridges about 57% of all available land. Pangia, however, was a true superc continent, a colossal amalgamation of Earth's present-day seven continents, which slotted together during the Carboniferous period, more than 330 million years ago. But most of the land it was made from is several billion years in age and would have been assembled in a number of different ways long before Pangia took shape.
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In fact, Earth's current continental cores have been crashing into one another, binding and then breaking apart in a great cycle of superc continent assembly, which plays out over periods of around half a billion years. As such, there would have been time for at least a handful of prehistoric superc continents in the run-up to Pangia's existence, with each exerting their own profound influences on our planet's oceans, climate, and its early life. The mechanism responsible for
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creating land on Earth and assembling it into superc continents is powered by plate tectonics. the chaotic interactions between colliding chunks of the Earth's shattered crust. Our planet's crystalline outer shell is fractured into many massive rigid slabs of deep lying rock known as tectonic plates which float at top the liquid upper mantle. These plates tend to grind up against one another along their margins to create enormous amounts of friction, heat, and ultimately magma.
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And it is here where the first scraps of ancient continents would have started to emerge. Back then, the brunt of Earth's crust would have been oceanic, basaltic, and loaded with heavy elements, rendering it flat, thin, and dense. As such, when these plates collide at a convergent margin, oceanic crust is invariably forced downwards, causing it to subduct into the Earth's molten mantle and melt into magma. This rising magma then returns to the surface and solidifies into
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chemically distinct continental crust in the form of volcanic island arcs like the Illutian Islands. These ignous rock formations would have been the first type of land to protrude the oceans of the young earth more than 4 billion years ago at the start of the Aran period. As primordial oceanic crust was recycled into lower density volcanic islands, they were able to avoid being swallowed into the Earth's interior and could start clustering and accreting at top subduction zones.
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But these protocontinental islands would have still been highly unstable, plagued by erosion, and prevented from forming anything larger by vigorous tectonic activity beneath them. However, the continuous melting of material in the upper mantle was depleting it of dense elements like iron, calcium, and aluminium, leaving behind a residue that was much lighter and more resistant to Earth's internal heat. As such, gigantic blocks of depleted felick rock began to condense
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in the Earth's early lithosphere, forming deep crystalline roots of continental crust. And at the sheltered surfaces of these lithospheric roots, protocontinental islands could now begin accumulating into larger, thicker shieldlike aggregations of land, thereby completing the sculpting of Earth's first coherent continental building blocks known
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as cratons are the jigsaw pieces of superc continent formation. They are persistent blocks of continental crust which have remained stable for billions of years thanks to the rigidity, buoyancy and melt resistance of their deep roots. Instead of sinking and melting like oceanic crust, cretonic continental crust can linger at top convergent margins and follow the flow of oceanic subduction to drift towards other blocks. As such, Earth's oldest cratons have been concentrated along subduction
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zones and assembled into many different configurations during their multi-billionyear lifespans before breaking apart along rifts where new oceanic crust is created to push them apart. Together this provides the mechanism of continental drift which drives both the formation and breakdown of cratons into superc continental
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aggregations. One of the oldest surviving today can be found in West Canada. The slaveraton named after the river which intersects it. In addition to being an invaluable region economically, rich in diamonds, minerals, and precious metals, it is also home to some of the oldest rocks we've ever found on Earth. Like the Acastaster, some 4 billion years in age. This implies that the slaveraton may have been one of Earth's earliest blocks of stable continental
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crust. Another is the 3.8 8 billiony old pilbara kraton in Western Australia home to some of the earliest fossilized life signs that we have. Elsewhere on Earth do we find biological signatures of a similar age in the capal craton of South Africa and that's not the only striking similarity shared by these disperate regions. In fact, they each show rock formations, mountain belts, and mineral occurrences of almost identical ages and compositions, strongly implying a shared
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origin for these remote blocks of land. As such, they may hold the key to understanding Earth's earliest so-called superc continent, Valbara.
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Valbara may have been the first continent on Earth, uniting the Capval and Pilbara with a number of lost land masses about 3.6 billion years ago, around the same time that life was starting to emerge on the deep ocean floors. Little is known of this mysterious island save for that it would have been a barren smoldering wasteland in the order of a few thousand km wide. Despite being devoid of any life on its surface, Valbara's landscape would have still been rippled by a few
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large mountain ranges and volcanoes raised during the collision of its constituent cretic blocks. An Aran era link between its two surviving cratons was first acknowledged back in 1976 when mountain basins with similar compositional characteristics were identified in both South Africa and Australia. At first, it was believed their similarities were the product of their identical ages, therefore exposing them to the same oceanic and atmospheric prerequisites during their formation. But in
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1996, retired University of Washington geologist, Professor Eric S. Cheney, proposed a more direct explanation that the now desperate Catval and Pilbara were once part of the same supercontinental assembly, which he nicknamed Valbara. In the years since, numerous scientific studies have supported the existence of this land mass with quantitative evidence through mathematical reconstructions. But it challenged the other conventional explanation of the time which had been established a few years
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earlier. In 1993, North Carolina geologist Professor John JW Rogers proposed the Earth's earliest cratons once belonged to another superc continent which he called Ur is another hypothetical protocontinent described by Rogers to contain the aforementioned kratons alongside a handful of Earth's other ancient aran blocks including two more from Africa and Australia in the Yil Bulgan and Zimbabwe kratons, some small slithers of Madagascar and Antarctica, and finally the Darwis and Singboom
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kratons of India. But crucially, Roger's reconstruction has them in a configuration that places the Catval and Pilbara on opposite sides of the same snaking Australiaized island and not directly connected as they are in models of Valbara. As such, reconstructions of these two superc continents cannot generally be reconciled and are thus deemed incompatible ideas. Much like Valbara, however, Ur would have constituted a barren, broadly lifeless expanse, straddled over a
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subduction zone in low latitudes around the equator. And whatever the case, both continents would have started to disappear around 2.8 8 billion years ago when either Valbara would have rifted and broken apart into kratons or the fragments of Ur would have been accreted into the next phase of the superc continent cycle with parts of Africa, Australia and India now in play on the young earth. The next entrance would be from North America as the slaveraton was added to the mix.
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As we mentioned, the slaveraton may be as old as up to 4 billion years, but it wouldn't have figured in the continental equation until at least 3 billion years ago. Up until that point, Earth's early mantle and crust would have radiated too much excess heat to facilitate the formation of very large land masses. But late in the Archan period, the crust finally cooled so that larger super cratonic aggregations could start to take shape and be supplemented by continuous bouts of island
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arcretion. Before long, Earth's first true superc continent was forming as the slaveraton latched onto the fragments of Ur, followed soon after by the Corellia and Cola Kratons, two of the earliest recognizable scraps of Europe today. And after being bolstered by accretion and custal extension, the final piece of the puzzle would be the North American superior kraton, whose head-on collisions some 2.7 billion years ago folded and metamorphosized rock in what is known as the algaman
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orogyny of mountain building. Also known as the Canoran origin in Canada. It's completed the torid assembly of Earth's next great superc continent,
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Kenneland. Kennorland was probably the second distinct iteration of Earth's superc continent cycle, though it may have been the first to actually connect more than 3/4 of available land. Much like Pangier, Kenneland was a slightly curving north south oriented land mass extending more than 50 million square kilm at its height. It contained theratons of both Valbara and Ur alongside large swads of modern-day North America, Greenland, Scandinavia, and even North China.
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The assembly of so many disperate blocks laced its landscape with mountain ranges and volcanoes whilst seeding its constituent kratons with abundances of precious metals and mineral deposits. Simple microbial bacteria and ara life forms were now wellestablished in its shallow waters and coastal areas. But they faced a more challenging environment than before due to the tricky geography of the newfound superc continent. Its elongated sea shape would have obstructed the flows of oceanic currents
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that would otherwise regulate sea temperatures, leaving some areas inhospitable and pruning the marine biosphere. But the most devastating effects on early life would not be felt until the superc continent started to fracture about 2 1/2 billion years ago. As the Archan period drew to a close, a great switchover was occurring deep in the Earth's interior as its contemporary core mantle accretion structure stabilized beneath the crust. This catalyzed a spur of tectonic
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activity which pushed plates apart and caused Kenneland to start rifting, casting its fragments to higher latitudes thereafter. This allowed rainfall to increase across virtually all surviving land masses, which drove up erosion and weathering and brought about a reduction in the level of atmospheric CO2. Back then, however, the sun would have only been shining around 80% of its current intensity. And so, this gradual reduction in the greenhouse effect triggered a rapid collapse in Earth's
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global temperatures. Before long, a runaway glaciation period was unfolding as temperatures fell so sharply that even the oceans around the equator began to freeze 2.4 billion years ago. And the break up of Kennaland had set in motion the first snowball Earth ice age, cutting off the exchange of gases between the sea and sky. As a result, biologically produced oxygen was now no longer being absorbed into the oceans and could instead accumulate in the atmosphere to more
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than 100 times its previous concentration. But this sporadic jump wre havoc on Earth's delicate early biosphere, proving fatal for more than 80% of its archal microbial cells. Those that survived were then forced to evolve structures that could tolerate the newfound quantities of oxygen. And it was this early instance of natural selection which yielded the first ukareotic cells. Single-sellled organisms with an internal nucleus for storing and sharing genetic
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information. An inalienable basis for all living things to this day.
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The breakup of Kenneland coincided with a highly dynamic period in the Earth's tectonic history as its various custal fragments shuffled around for more than half a billion years on route to their assembly in the next great superc continent. As Kennoland ruptured from within, its North American kratons were separated into two distinct aggregations. One was Clavia which united the slave Wyoming Ray and Hearnatons. The other superior saw the superioraton escape with the Corellia
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Colarratons before the latter broke free to begin the formation of Baltica, the proto European Paleo continent. Scavia, meanwhile, embarked on a half billion-year voyage to the other side of the frozen planet where it would encounter several additional late aran kratons from Siberia, Greenland, and other parts of Europe. Together, they formed a frosty protocontinent known as Arctica, which soon collided with Baltica and the wandering superior Kraton to form an even larger
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supercontinental precursor. known as Nenina, an acronym for North Europe, North America. It connected a vast expanse of modern-day Finland, Sweden, and Russia with swavs of the USA, Canada, and Greenland, raising in its wake yet more mountain ranges and other geological features. But it was not yet a true superc continent as Nenina would soon join with two other macrocontinental groups. One was the fragments of ore which had now evolved to encompass a large stretch of
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modern-day Australia and Antarctica alongside pieces of India, South Africa, and China. The other was Atlantica, the protos South American continental corps which joins the Amazonia, San Francisco and Rio deel Plata Kratons with important building blocks of Africa like the Congo and West African Kratons. Atlantica took shape in the southern hemisphere far from the chaos of Nenah's torid assembly. But once it was fully formed about 1.9 billion years ago, it would
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then latch itself onto the Eurasian underside of Nenina while the fragments of attached themselves to the North American side, thereby completing the formation of the next true superc continent Colombia.
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Colombia was a terrestrial titan which unified most of the available kratons and protocontinents around 1.8 billion years ago. It gets its name from the Colombia plateau of the United States where curious geological similarities with East India were unearthed and investigated by Professor John Rogers in the early 2000s. He postulated their existence in a messoprotozoic superc contininent as a necessary precursor to pangier which united the super groupoups of nenina Atlantica and his own original
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protocontinent. And while a number of differing reconstructions in the years since have challenged this exact arrangement, they all placed the largest protocontinental chunks along a massive snaking subduction zone on its western margin, extending almost 13,000 km. The kratons lying along this margin would have enjoyed major supplementation from the accretion of magma below, resulting in prolific crustal extension, which would have bolstered the superc continent's most significant components,
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many of which make up important building blocks of the seven continents we know to this day. Lorentencia, the great heart of modern-day North America, stabilized as a single land mass inside Colombia, having formed from a reunification of Scavia and Superior's Kratons. Also fully formed were the Paleo continents of Baltica, Siberia, Amazonia, and Congo Kalahari. and they would soon be freed to start acting as their own self-determining land masses. One and a half billion years
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ago, Colombia was rifting from within, stretching so thinly along oceanic margins that it ruptured into constituent fragments. But unlike in previous iterations of the superc continent cycle, these fragments would not regroup around the same subduction zone that knitted together Colombia. Rather, each of the surviving pieces were banished on their own lonely path towards the opposite side of the planet, only destined to reconvene some 300 million years later. In their wake, the Morovia super
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ocean was opened around them as the fragments of Colombia regrouped into a new superc continent configuration Roinia.
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Roinia was Pangier's most recent precursor which existed for about half a billion years in the late protozoic period. Unlike previous superc continents which were only discovered alongside evidence for their existence, the need for a pre-Camrian superc continent to provide the pieces of pangier was recognized all the way back in 1970. Back then however it was known as Pangier 1 with the name Roinia coined some 20 years later. Much like in Colombia, the Lorentia superraton would have made up
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the largest piece of Roinia's structure. This time nestled right at the very heart of the new superc continent. surrounded by an almost fully formed Australia and Antarctica, Baltica and Amazonia, and intersected by smaller pieces of protoasia and Africa. The collision of all these massive cretic blocks just over a billion years ago catalyzed a myriad of mountain building origins. Most notable are the Grenville origin which raised enormous mountain belts across North America and the SPCO
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Norwegian orogyny which played out around Europe. But mountainous scars from its turbulent formation can be seen across virtually all major cratons today. Unlike with previous assemblages, however, Rodinia's formation does not appear to have triggered the same level of vulcanism with fewer characteristic mineral occurrences when compared with earlier superc continents. This is likely a result of its extroverted assembly as Roinia was formed from the collision of fragments
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on the other side of the world and not around the same subduction zone which glued together Colombia. Also, unlike previous superc continents which were broadly barren and lifeless on their surfaces, Roinia would have seen a spectacular variety of new life fors colonize its land as algae and fungi swept across the rock faces of its damp wetland environments. And by the time the superc continent started to break apart, its life forms were verging on the precipice of another
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biological breakthrough, triggered in part by yet more environmental changes brought about by its fragmentation. Roinia began fracturing about 850 million years ago when a super plume of deeply lying mantle material is thought to have rifted the superc continent from underneath. soon after and the Congo San Francisco crettonic aggregation either broke off from the rifting landmass or plowed straight into it to the same effect. Either way, shock waves were sent reverberating into the very heart
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of the superc continent, unhinging the delicate unification of Lorentia, Antarctica, and Siberia. As they started sliding apart, the surviving land mass drifted over the equator where yet more volcanism and seismic activity shattered its superratons further, detaching Australia and the African Kalahari Kraton. This gradual separation into smaller fragments once again catalyzed a major shift in Earth's climate with the creation of new ocean basins raising sea levels between fragments and driving
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increased rainfall. Before long, the greenhouse effect was stifled once more as global temperatures plummeted to trigger a second great snowball earth ice age about 700 million years ago. But unlike the former, this ice age did not last as long as a surge in volcanic activity seen replenished the atmospheric layer with thick concentrations of warming greenhouse gases. And as the ice started to thaw around 600 million years ago, life was once again forced into a number of
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hurried evolutionary leaps, priming yet another of the most important characteristics in the modern-day biosphere, multi-ellular life forms. Thereafter, some posit that the Earth's protocontinental fragments would have converged upon the South Pole into another lifebearing pangia precursor known as Penosia. But alas, most geologists dispute its existence, instead supposing the shattered fragments of Roinia to have drifted to opposite ends of the planet. Lorentencia, Siberia, and Baltica would
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have moved northwards, opening the Apotus Ocean in their wake. Meanwhile, the fragments of Africa, South America, Australia, India, and Antarctica drifted southwards, where they then reassembled into a massive mega continent known as Gonduana, one of the best known pre-cambrian land masses.
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Gonduana began forming from the southern drifting fragments of Roinia about 800 million years ago, completing around the time of the Cambrian explosion when multisellular life forms spurted the first defensive adaptations. And by the time of its accretion into Pangier, it was home to plants, insects, fish, and all manner of amphibious creatures across much of its jungled surface. Though never actually a superc continent by definition, Gonduana still bridged
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more than 100 million square km of land at its height, making it larger and more extensive than Kennaland despite only comprising just over half of the available terrain. The other half consisted of Lorentia, Baltica, Siberia and a few other north hemisphere cratons which would eventually reconvene into the other side of Pangier. Just over a hundred million years after the completion of Gonduana, Lorentia and Baltic merged with a few other land masses to form Eura, another prepier protocontinent
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which hosted ancient thick forests of simplistic early trees across much of its expanse. By about 400 million years ago, it had accred the great Siberia craton to form Lorasia. The unification of North America, North Europe and Asia, which made up one half of Pangier. The other half was Gondana. And by 350 million years ago, these two sides were homing in on a collision, closing the rear ocean between them and opening around them the panthalacic super ocean. And then finally about 330
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million years ago, these two macrocontinents collided and stabilized as another sea-shaped north south aligning land mass known as Pangia. [Music] Like Gonduana and Lorasia before it, Pangia was proud by a plethora of insects, plants, and giant reptiles. But on this new superc continent, they faced a poorly suited, inhospitable climate with vast mountain ranges disrupting its wind and rain patterns, rendering dry, isolated areas where many ancestral animals would have struggled to survive.
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Out to sea, meanwhile, and the curving geography of Pangier cradled its interior oceans, Tethus and Paleoteis, preventing cool Arctic waters from regulating their temperatures and raising them above the tolerance of early coral reefs. These factors likely contributed to one of the most cataclysmic events ever to ravage the young biosphere when more than half of all life fors died out in what is known as the perian extinction event. Parched forests burned to the
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ground with the animals relying on them starving to death while levels of marine life receded to less than a fifth of their previous abundance. on land. The only reptiles to survive this catastrophe were those of aven lineage, which would go on to evolve into the family of dinosaurs soon after. Before that, however, the superc continent pangir would start to break apart on route to the configuration of the seven continents we know today. About 1180 million years ago, the first
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pieces of pangier to divorce were the last to unify in its formation as Larasia and Gonduana were ripped from one another, opening the Atlantic Ocean between them. Next, and Gonduana would rupture from within, tearing along the boundary we see between Africa and South America today to open the south of the Atlantic Ocean. North America would then break free from Eurasia and drift westwards to nestle above its southern counterpart on the east side of Africa. Meanwhile, and India, Madagascar,
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Australia, and Antarctica were all coming unbound and drifting towards their present positions, raising among others the Himalaya mountain range and opening the Indian Ocean between them. And by about 5 million years ago, the present-day configuration of the seven continents had largely been completed, thus bringing us to the end of our story today. But it is not the end of the story entirely because the superc continent cycle is still in action today. And about 2 to 300 million years
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from now, another sprawling land mass will take shape as the seven continents amalgamate. And there's no shortage of ideas, models, and hypothesis for what this pangia proxima might look like. Until then, however, I thank you very much for watching this video and I bid you good night. C signing out.
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