00:00Ten million years ago, the Himalayas did not exist.
00:04In their place lay a vast, warm, swampy basin, a low green world walled off from the rest
00:09of Asia by mountains that were still climbing.
00:12And trapped inside that basin, evolution went somewhere strange.
00:16This is the story of a lost world on the Tibetan plateau.
00:19The plateau we know today is called the roof of the world.
00:23Four and a half kilometers above sea level, thin air, hard wind, cold enough to freeze
00:28a person solid in a single night.
00:31Nothing lives up there now that could not survive that cold.
00:34But the rocks under it tell a different story.
00:37And so do the bones inside them.
00:40For over a century, geologists assumed the plateau rose slowly and steadily, like a slow elevator
00:45going up.
00:47The fossils say something else entirely.
00:49They say that for millions of years, a canyon existed in what would become the high plateau.
00:55That canyon existed about 160 kilometers north of where the plateau's rim is today.
01:01It held a forest.
01:03And it held the animals that lived in it.
01:05Animals that had no business being that high, so long ago.
01:09In 2023, a research team announced what they had found in the debris of a basin called the
01:14Luntala.
01:1542 kinds of fossilized teeth and bone fragments, belonging to at least 19 species.
01:21Among them, a cat.
01:23And not just any cat.
01:25A cat built like a honey badger, heavy-bodied, thick-limbed, with jaws strong enough to break
01:31a bone.
01:32They estimated its weight at 130 kilos.
01:36Bigger than the biggest snow leopard alive today.
01:39For comparison, the average honey badger weighs 9 kilos.
01:43This animal was 14 times that.
01:46This cat was built to hunt things considerably bigger than a rabbit.
01:50And it was not alone.
01:52The same sight produced an elephant smaller than a dog.
01:55And a turtle almost 2 meters long, that ate leaves and had no teeth.
02:00No elephant, no cat, no turtle that lives today behaves the way these did.
02:05So what happened?
02:07What could turn a warm swamp into the coldest place outside the poles?
02:11The answer is geography.
02:13And it happened over 10 million years.
02:16The Indian subcontinent is moving north at about 5 centimeters a year.
02:20That does not sound like much.
02:23It is roughly the speed your fingernails grow.
02:26But over 10 million years, it is a collision on the scale of a planet.
02:30The Indian crust does not sink.
02:32It rams into Asia and pushes it up.
02:35Rock folds, layers stack, and the plateau rises like a wound that has not closed.
02:41As the plateau rose, the canyon closed.
02:44Water drained out.
02:46Air thinned.
02:47And the warm basin, cut off from the monsoon, cooled.
02:52Forests shrank back to the hills.
02:54Open grassland spread across the floor.
02:57An animal that evolved in a swamp, eating soft leaves, suddenly found itself in a landscape
03:02with no water, no cover, and no shade.
03:06Some adapted.
03:07Most did not.
03:09The fossil record shows the change plainly.
03:12At the bottom of the sequence, you find the animals of a warm lowland.
03:17Crocodiles.
03:18Forest tortoises.
03:20The kind of life that needs standing water and shade.
03:23Higher up, they disappear.
03:26The layers above them hold the animals of open ground, of dry air, of hard seasons.
03:31The further you go up in the sediment layers, the fewer species you find, and the more of
03:36them look like the animals we know today.
03:38And here is the part that makes the Lundpula Basin genuinely important.
03:42It is not just that strange animals lived somewhere.
03:46It is that the strange animals tell us how tall the plateau was, and when it got that tall.
03:51The rocks hold a record of the height.
03:53The animals read it out loud.
03:57This works because of a paleontological principle that has been tested again and again.
04:01Cold-blooded animals and warm-blooded animals respond to altitude in measurable ways.
04:07As you climb, the air holds less oxygen, and the temperature drops about 6 degrees for every
04:12kilometer you gain.
04:14Species living height tend to be smaller, because a smaller body is easier to keep warm.
04:19Predators that rely on bursts of speed do not do well when the air is too thin.
04:24Leaf-eating animals need more food, because thin air burns calories faster.
04:29So the fossil group in a particular layer is itself a measurement of altitude.
04:33If you find a swamp-dwelling crocodile, the place was low.
04:37If you find a cold-adapted rodent, the place was high.
04:41This is not a guess.
04:42It is a calibration, built from hundreds of modern ecosystems measured one by one.
04:48The Lungpula Basin contains both, in different layers, stacked one above the other.
04:54That is how the team reconstructed a rise, not just a presence.
04:58They read the altitude off the animals themselves.
05:01They went further.
05:03They used the fossil species to estimate temperature and elevation at each stage.
05:08The result, published in 2023, was a basin that sat at about 3,000 meters, and then climbed.
05:15That climb was not instant.
05:17It took millions of years, and it was not smooth.
05:20There were pauses.
05:22There were bursts where the ground jumped a few hundred meters in a geological blink.
05:26And it explains something about the modern climate that no amount of rock alone could tell you.
05:31The Himalayas and the Tibetan Plateau changed the weather of an entire hemisphere.
05:36They blocked the monsoon rain from reaching deep into Asia.
05:40They created dry interior.
05:43They helped drive the wind system that shapes everything from Indian agriculture to Arctic
05:47ice.
05:48When that plateau was low, that whole machine was off.
05:52Imagine the monsoon reaching further north.
05:55Imagine forests where the Gobi now sits.
05:58Imagine a wetter, greener Asia, with rivers that no longer exist.
06:03A low plateau means a different monsoon, a different wind belt, a different set of deserts
06:08and forests.
06:09Which means the fossils of a strange cat and a strange turtle are also a record of a planet's
06:14weather.
06:15That is the reason this find matters.
06:17Not the monsters.
06:19The clock they carry.
06:20Now, the two most famous of the animals.
06:24First, the dwarf elephant.
06:27It stood roughly the height of a large dog.
06:30Its teeth were simplified, losing the complex grinding ridges that modern elephants depend
06:34on.
06:35This is a classic pattern for animals on islands and enclosed basins, a condition paleontologists
06:41call insular dwarfism.
06:43The rule is simple.
06:44When the habitat is limited, a small version of a large animal outcompetes the large version.
06:50It needs less food.
06:53It matures faster.
06:55It fits into places the big one cannot.
06:57You see it on islands all over the planet.
07:00In the Mediterranean, pygmy elephants.
07:03On the Indonesian island of Floris, extinct elephants the size of a pony.
07:08The Tibetan basin is a version of an island, except the barrier is not water.
07:13It is wall.
07:14And the wall did the same thing water does.
07:17It cut the population off, and left it to solve the problem of limited space on its own
07:22terms.
07:23Second, the leaf-eating turtle.
07:26Almost two meters across.
07:28Thick, heavy shell.
07:30No teeth, just a horny beak for cutting plants.
07:34This is a large vegetarian tortoise, the kind you find on islands with no predators and plenty
07:39of vegetation.
07:40Those animals reach sizes you would not expect, because the usual limit on shell size is predation.
07:46If nothing is hunting you, and the vegetation is low and dense, getting bigger is a good
07:51strategy.
07:53Bigger means a longer reach, a stronger bite, and a shell too heavy for most predators to
07:57flip.
07:58So both species are following the same logic from opposite ends.
08:02The cat is a predator without a bigger predator above it, growing toward the maximum its prey can
08:07support.
08:08The elephant and the turtle are herbivores in a closed system, shrinking or expanding depending
08:13on what the plants offer.
08:15None of this makes sense in a normal mountaintop.
08:18All of it makes sense in a warm basin with walls around it.
08:22And that is the trick of the sight.
08:24Every animal in the layer is a clue to the same question, how high were we standing when
08:28this one died?
08:30And that is a rule you can carry anywhere.
08:32Look at the animals, and you can read the environment they had to survive.
08:37The last piece is what happened to the basin's creatures.
08:41Most of them are gone.
08:42The giant cats, the dwarf elephants, the leaf-eating turtles, the bear dogs, the ancient rhinos.
08:49Their descendants are not living in Tibet.
08:52If they left any descendants at all, they left them elsewhere.
08:55Some species held on in valleys for a while.
08:58Some moved downhill and adapted.
09:01Some were simply replaced by animals that were already better suited to the new conditions.
09:06That is what the record shows, not a single catastrophe, but a long, uneven retreat.
09:13Geologists call the driving force Indian and Asian continental collision.
09:17Paleontologists call it an experiment.
09:20One that ran for 10 million years, and never wrote down its methods.
09:24The Tibetan Plateau is a machine for changing animals.
09:28It closed a warm forest, raised a wall of rock, and turned a swamp into a high cold desert.
09:34And every so often, the machine leaves a record of what it did.
09:38A cat the size of a person tells you the forest was rich.
09:42A turtle with no teeth tells you the vegetation was low and soft.
09:46An elephant the size of a dog tells you that space and food were limited, and that being
09:51small was an advantage.
09:52Put them in the same rock layer, and you have a snapshot of a world that no longer exists.
09:58That world was lost so long ago that the ground it stood on has been lifted 3 kilometers
10:02into the sky.
10:04You can walk across it today.
10:06It is cold, dry, and almost empty of life.
10:10But it holds the bones of a warm swamp.
10:13Somewhere in the Lumpala Basin, another fossil is waiting to be found.
10:17And when someone eventually pulls it out of the ground, it may tell us something about
10:21the giants of that lost world that we have never guessed.
10:24The mountains are still rising.
10:26About 5 centimeters a year, every year, for as long as the collision lasts.
10:31The questions are still open.
10:33And the past, buried under the highest place on earth, is not finished talking yet.
10:38But to me, I think that feels very happy.
10:38The two holes that are still coming out.
10:38I think you can barely see them.
10:39The wildest?
10:39The first thing.
