When did primates appear, and when did Pithecanthropus appear? What do Tolkien's heroes and the Floresian Man have in common? How much of us is Neanderthal and how much is Denisovan? Who are we, when and where did we come from?

The latest data show that the closest relatives of primates are not tupai at all, but woolly wings (kaguans). These arboreal mammals can be found today in Southeast Asia.

Kaguan

35 Ma ago, fossil monkeys appeared - the so-called parapithecus.

25 Ma ago - an offshoot of the first apes. They were already quite large, had no tail, and were more intelligent than their ancestors.

12-9 million years ago, Dryopithecus emerged from them - the ancestors of gorillas, chimpanzees and you and me.

7 million years back, upright posture appeared. Our ancestors split from the chimpanzee lineage. Australopithecus will appear in about 3 million years. But they will still be little different from monkeys.

2.5 Ma back (or a little more) is the “Rubicon” in human evolution. Stone tools appear, and the function of the hand becomes stronger and more complex. There is a trend toward brain enlargement. The skilled man (Homo habilis) appears.

Reconstruction of Homo habilis

2 million years Pithecanthropus enters the evolutionary “scene” back. A working man (Homo ergaster) appears. His brain, like himself, has become even larger, and it seems that his menu now includes meat. Erecti and other types of “proto-humans” appear. All of them will interbreed with our distant ancestors, but in the end they will die out. The first exodus from Africa.

From 400 to 250 thousand years ago, about a dozen species appeared in the genus Homo. Most of them will die out, but some will have time to “have children” with our direct ancestors - sapiens.

200 thousand years Back in Africa, Homo sapience (Cro-Magnons) developed. It must be said that long before this, another almost human species appeared on Earth - the Neanderthals. They live in Europe and are the ancestors of Homo ergaster, who left Africa 2 million years ago.

80 thousand years A small group of “almost” people stands out back. In a biological sense, they are practically no different from us. The estimated size of the group is about 5 thousand individuals. At the same time, another exodus from Africa took place. Although in reality, of course, there were many such outcomes. Proto-people migrated from the “dark continent” and back.

40 thousand years modern people appear back.

Neanderthals

As we already know, Neanderthals settled Europe much earlier than our direct ancestors - the Cro-Magnons. But having left Africa 80 thousand years ago, the “invading” sapiens gradually replaced the “indigenous” Neanderthals, who first went high into the mountains and then died out completely. Although there are different points of view on this matter. The fact is that it is still unclear whether repression as such took place or not. It is unlikely that our rather “slender” ancestors would have thought of fighting with the big Neanderthals. In addition, sapiens were hunter-gatherers, with a group size of, for example, about 20 people. And any war would be fatal for them. Scientists believe that most likely the displacement occurred due to the more successful adaptation and intellectual abilities of sapiens; they hunted better and, accordingly, ate more meat.

Reconstruction of a Neanderthal man and woman, Neanderthal Museum, Mettmann, Germany

But that's not even the point. Archaeologists have found skeletons with intermediate characteristics of Neanderthals and Cro-Magnons (sapiens). Most likely, there was mixing between them and even quite active. For recent years The Neanderthal gene was almost completely deciphered. It turned out that “Neanderthal” admixture is present in sapiens - it ranges from 1 to 4% (on average - 2.5%). If you think that this is not enough, scientists advise calculating the percentage of Indian genes in the modern US population. And they themselves answer: there will be less Indian admixture than Neanderthal admixture. So who went extinct - Neanderthals or Indians - still big question. And this despite the fact that purebred Indians are still alive and well.

Neanderthals have simply always been few in number. Their species has never been numerous. Among other things, they were probably generally haunted by failures - for example, natural disasters.

Neanderthals were larger than Cro-Magnons. They had a more sloping forehead, huge faces and teeth. They were distinguished, by the way, by a very large but flattened brain. But in a biological sense they were not fundamentally different. Of course, these were greater differences than between modern races, but on the whole they were differences within, or almost within, the same species.

Because Neanderthals had a speech bone, a tongue, and other speech organs, scientists believe that Neanderthals most likely talked among themselves. Although they did it differently from the Cro-Magnons, since they had huge, clumsy jaws. The Neanderthals had a high culture (naturally, if you don’t compare it with ours), they made complex tools, the main ones of which were: a scraper (for stripping skins), a pointed point (for hunting), and a chopper (left over from Pithecanthropus times). They were distinguished from the Cro-Magnon tools by their monotony. Sapiens were distinguished by great imagination and liveliness of mind. Neanderthals lived a maximum of 45-50 years. Their average life expectancy was 30-35 years (however, this is not much different from the life expectancy of ordinary people in the Middle Ages, and even at the beginning of the last century).

Reconstruction of a Cro-Magnon woman

Human evolution is not a straight line, but rather resembles a branched tree. The fact is that whenever primates left Africa each time, they found themselves in territorial isolation. For example, they ended up on an island, or occupied a certain territory. We have already considered two branches of the evolutionary tree - Neanderthals and us - sapiens. Scientists also know two more main species.

Florentine man

He is also called the hobbit. In 2004, archaeologists found skeletons on the island of Flores, in southeastern Indonesia. One of them was the skeleton of a woman 1 m tall and with a brain like a chimpanzee - about 400 grams. Thus, a new species was discovered - the Florentine man.

Sculptural portrait of Flo

Their brains weighed very little, and yet they managed to make not the simplest stone tools. They hunted “dwarf elephants” - stegadons. Their ancestors appeared on Flores (which at that time was probably connected to the continent) 800 thousand years ago. And the last Florestian man disappeared 12 thousand years ago. Having appeared on the island, these Pithecanthropus evolved to the state of dwarfism. In tropical conditions, DNA is practically not preserved, so it is not yet possible to isolate the Florentine man gene. This means that it is impossible to say whether there is even a drop of “Florentine blood” in us.

Even pragmatic anthropologists like to argue that legends about gnomes are nothing more than ancient “memories” of encounters with Pithecanthropus of all stripes. In Europe - with Neanderthals (stocky, with a large head on a short neck), in Australia and Micronesia - with dwarf Florentine people.

Denisovsky man

Denisovan man dominated Asia. Settlements of this species were found in Altai. This is the third great view(except for Florestian man, who lived on only one island) Homo. DNA was extracted from the remains. The results showed that it is different from both ours and Neanderthal DNA.

Excavations in Denisova Cave, Altai

However, we still have a percentage of the Denisovan gene, but it is very tiny, so we cannot call them our ancestors.

It is difficult to judge the appearance of Denisovan man - very few fragmentary remains have been found. However, there are remains (the DNA of which has not yet been isolated) that indicate that Denisovan had very specific features that were different from sapiens: for example, he had a very sloping forehead and overly large eyebrows.

After the exodus of Homo sapiens from Africa, at least 4 main species simultaneously lived on Earth: sapiens - in Africa, Neanderthals - in Europe and Western Asia, Denisovans - starting from Altai and further east, and Floresians - only on the island of Flores.

On the islands of Micronesia, bones of close ancestors of the Floresians were found, who lived there only 2 thousand years ago - at the time of Christ. On the island of Java, as well as in Asia, other lines of development of Pithecanthropus were discovered. All of them are dead ends, few in number and are not our ancestors.

Our beloved blue planet is constantly being hit by space debris, but due to the fact that most space objects burn up or fall apart in the atmosphere, this most often does not present any serious problems. Even if an object reaches the surface of the planet, it is most often small, and the damage it causes is insignificant.

However, of course, there are very rare cases when something very large flies through the atmosphere, and in this case very significant damage is caused. Fortunately, such falls are extremely rare, but it is worth knowing about them, if only to remember that there are forces in the Universe that can disrupt people’s everyday lives in a couple of minutes. Where and when did these monsters fall to Earth? Let's look at the geological records and find out:

10. Barringer Crater, Arizona, USA

Arizona apparently couldn't get enough of the Grand Canyon, so about 50,000 years ago it added another tourist attraction when a 50-meter meteorite landed in the northern desert, leaving behind a crater 1,200 meters in diameter and deep. at 180 meters. Scientists believe that the meteorite that created the crater flew at a speed of about 55 thousand kilometers per hour, and caused an explosion about 150 times more powerful than the atomic bomb dropped on Hiroshima. Some scientists initially doubted that the crater was formed by a meteorite, since there is no meteorite itself, but according to modern scientists, the stone simply melted during the explosion, spreading molten nickel and iron throughout the surrounding area.
Although its diameter is not that large, its lack of erosion makes it an impressive sight. Moreover, it is one of the few meteorite craters that look true to its origin, making it a top-notch tourist destination - just as the Universe intended.

9. Lake Bosumtwi Crater, Ghana


When someone discovers a natural lake whose outline is almost perfectly round, it is quite suspicious. This is exactly what Lake Bosumtwi is, reaching about 10 kilometers in diameter and located 30 kilometers southeast of Kumasi, Ghana. The crater was formed by a collision with a meteorite with a diameter of about 500 meters, which fell to Earth about 1.3 million years ago. Attempts to study the crater in detail are quite difficult, since the lake is difficult to reach, it is surrounded by dense forest, and the local Ashanti people consider it a holy place (they believe that touching the water with iron or using metal boats is prohibited, making access to nickel at the bottom of the lake is problematic). And yet, it is one of the best preserved craters on the planet. at the moment, and a good example of the destructive power of megarocks from space.

8. Mistastin Lake, Labrador, Canada


The Mistatin impact crater, located in the Labrador province of Canada, is an impressive 17 by 11 kilometer depression in the earth that formed approximately 38 million years ago. The crater was likely originally much larger, but has shrunk over time due to the erosion it has suffered from the many glaciers that have passed through Canada over the past millions of years. This crater is unique in that, unlike most impact craters, it is elliptical in shape rather than circular, indicating that the meteorite fell at an acute angle rather than flat, as is the case with most meteorite impacts. Even more unusual is the fact that in the middle of the lake there is a small island that may be the central rise of the complex crater structure.

7. Gosses Bluff, Northern Territory, Australia


This 142-million-year-old crater with a diameter of 22 kilometers, located in the center of Australia, is an impressive sight from both the air and the ground. The crater was formed by the impact of an asteroid with a diameter of 22 kilometers, which crashed into the Earth's surface at a speed of 65,000 kilometers per hour and created a crater almost 5 kilometers deep. The energy of the collision was approximately 10 to the twentieth power of Joules, so life on the continent faced great problems after this collision. The highly deformed crater is one of the most significant impact craters in the world and never lets us forget the power of one large rock.

6. Clearwater Lakes, Quebec, Canada

Finding one impact crater is cool, but finding two impact craters next to each other is doubly cool. That's what happened when the asteroid broke into two pieces as it entered Earth's atmosphere 290 million years ago, creating two impact craters on the eastern shore of Hudson Bay. Since then, erosion and glaciers have greatly eroded the original craters, but what remains is still an impressive sight. The diameter of one lake is 36 kilometers, and the second is about 26 kilometers. Considering that the craters were formed 290 million years ago and were subject to severe erosion, one can only imagine how large they were originally.

5. Tunguska meteorite, Siberia, Russia


This is a controversial point, since no parts of the hypothetical meteorite remain, and what exactly fell in Siberia 105 years ago is not entirely clear. The only thing that can be said with certainty is that something large and moving at high speed exploded near the Tunguska River in June 1908, leaving behind fallen trees over an area of ​​2000 square kilometers. The explosion was so strong that it was recorded by instruments even in the UK.

Because no pieces of meteorite were found, some believe that the object may not have been a meteorite at all, but a small part of a comet (which, if true, would explain the lack of meteorite debris). Conspiracy fans believe that an alien spaceship actually exploded here. Although this theory is completely unfounded and is clean water speculation, we have to admit that it sounds interesting.

4. Manicouagan Crater, Canada


Manicouagan Reservoir, also known as the "Eye of Quebec", is located in a crater formed 212 million years ago when an asteroid with a diameter of 5 kilometers fell to Earth. The crater with an area of ​​100 kilometers, which remained after the fall, was destroyed by glaciers and other erosive processes, but at the moment it remains an impressive sight. What is unique about this crater is that nature did not fill it with water, forming an almost perfectly round lake - the crater basically remained dry land, surrounded by a ring of water. A great place to build a castle here.

3. Sudbury Crater, Ontario, Canada


Apparently, Canada and impact craters are very fond of each other. Singer Alanis Morrisette's birthplace is a favorite place for meteorite impacts - the largest meteorite crater in Canada is located near Sudbury, Ontario. This crater is already 1.85 billion years old, and its dimensions are 65 kilometers long, 25 wide and 14 deep - it is home to 162 thousand people, and is also home to many mining enterprises, which discovered a century ago that the crater is very rich in nickel. for a fallen asteroid. The crater is so rich in this element that about 10% of the world's nickel production comes from here.

2. Chicxulub Crater, Mexico


The impact of this meteorite may have caused the extinction of the dinosaurs, but it is certainly the most powerful asteroid collision in the entire history of the Earth. The impact occurred approximately 65 million years ago when an asteroid the size of a small city crashed into Earth with an energy of 100 teratons of TNT. For those who like precise data, this is approximately 1 billion kilotons. Compare this energy to the atomic bomb dropped on Hiroshima, with a yield of 20 kilotons, and the impact of this collision becomes clearer.

The impact not only created a crater with a diameter of 168 kilometers, but also caused megatsunamis, earthquakes and volcanic eruptions across the Earth, greatly changing environment and sentenced the dinosaurs (and apparently many other creatures) to death. This vast crater, located on the Yucatan Peninsula near the village of Chicxulub (from which the crater gets its name), can only be seen from space, which is why scientists discovered it relatively recently.

1. Vredefort Dome, South Africa

Although the Chicxulub crater is better known, compared to the 300-kilometer-wide Vredefort Crater in South Africa, it is an ordinary pothole. Vredefort is currently the largest impact crater on Earth. Fortunately, the meteorite/asteroid that fell 2 billion years ago (its diameter was about 10 kilometers) did not cause significant harm to life on Earth, since multicellular organisms did not yet exist at that time. The collision undoubtedly greatly changed the Earth's climate, but no one noticed it.

The original crater is now heavily eroded, but from space its remains look impressive and are a great visual example of how scary the Universe can be.

History is written by people. And often biased. As a result, not even centuries later, but months and years later, people argue about how certain events actually happened?

Sergei Vladimirovich Klimenko, based on his unusual ability of retrovision (the ability to see the past), talks about some events in the history of mankind: reveals the secrets of Easter Island, Atlantis and the ancient continent of Mu, explores the history of Primorye, introduces readers to the unusual creatures inhabiting the planet, and explores the authenticity of myths legends, as well as much more from history from millions of years ago to the present day...

Below is a short article from the book by S.V. Klimenko “Secrets of humanity”:

What happened on Earth 65 million years ago? Why did dinosaurs die out en masse? This question has been of interest to many generations of scientists and simply curious people.

The most popular theories of earthly disasters are associated with the fall of large asteroids. Indeed, scientists have discovered a number of astroblemes (“star wounds”, craters) on Earth, the age of which is estimated at 65 million years. This is a giant astrobleme in Yucatan (Chiksulubskaya) with a diameter of 300 kilometers, Popigaiskaya (100 km), Kara (65 km) and Ust-Karskaya (25 km) in the Northern Urals, Kamenskaya (25 km), Gusevskaya (3 km). Thus, there is every reason to believe that at the turn of 65 million years ago, our planet was bombarded by a whole swarm of cosmic bodies ranging in size from 300 meters to 30 kilometers. And not all of them have yet been identified. After all, craters can be at the bottom of the sea. For example, in 1999, Norwegian geophysicists found a crater with a diameter of 40 km at the bottom of the Barents Sea. According to preliminary data, the time of the asteroid's fall is 150 million years ago. But now I'm interested in a different time period. Well, let's try.

Vision (11/6/2001)

Earth. Ferns, horsetails. Warm. Dinosaurs roam around, eating tons of greenery. Just in case, I ask the question - is there intelligence on the planet? I was led somewhere to the side. What is this?!

In the middle of the fern jungle there is a city! Everything is large and massive. Apparently giants live here. But this cannot be! 65 million years ago! But here’s another city, another one! Who lived at that time among the intelligent beings on our planet, and even built cities?! Here! Dinosaurs! Intelligent dinosaurs! Based on their appearance, I conclude that they are descended from predators: the jaws protrude forward, sharp fangs, but also narrower molars for thoroughly chewing food. The muzzle, if I can say so about an intelligent creature, is much shorter than that of its wild relatives, and the skull is very voluminous, somewhat rounded.

It’s interesting, but until now archaeologists have not found such skulls! They have proportionally developed arms, very strong and muscular. The tail barely reaches the ground. What about height? For comparison, I saw a “dinosapiens” fighting a tyrannosaurus with his bare hands. Moreover, the height of the “Dino” was slightly higher than that of the “Rex”. Let us remember that paleontologists estimate the height of Tyrannosaurus rex to be 5-6 meters with a weight of 10 tons. And the brain of such a colossus weighs only 0.5 kilograms! So our “dinosapiens” were apparently more than 6 meters tall! What a pity that all these pictures are visible through the haze! You can't make out the details! If you focus on the little things, you will waste time and your energy, and therefore you will see less.

Someone might say that many clairvoyants see clear pictures, and then convey what they saw in detail. My answer is that the methods of viewing the past are different. Some are shown pictures, and then everything is really clear and clear. A few can go directly to the Akashic Temple and view the records there, and here retell what they saw, as the American clairvoyant Edgar Cayce did. I remove information from the general and private information field directly, because in any thing there are particles of the universe, called akash, which absorb all the information about what is happening around and about the object itself. And this requires strength and energy. But I can choose the purpose of the research myself. However, let's return to dinosaurs. Of course, like any person, I was interested in the question of the technical achievements of our intelligent predecessors on the planet. As if in response, I saw spaceships launching from the surface of the Earth. There were many of them, several dozen. What's the matter?

Panic! Escape! I'm looking at the time before the disaster! Dino scientists saw an asteroid rushing towards the planet and, naturally, warned society. Of course, only a few flew away. Where? Were you able to survive? I have no answer to this.

But what about the main majority? They sank underground, preparing for disaster. Can you imagine, with such growth, what kind of caves they prepared?! Apparently, their skeletons are located underground. And over the past millions of years, the caves either collapsed or were filled with underground water. Maybe someday miners or speleologists will find traces of their life...

Now let's look for an asteroid. Here it is! Wow pebble! And behind it is a flock of so-called satellites - smaller stones. The asteroid enters the atmosphere, flares up, and splits into 9 fragments - 3 larger and 6 smaller. It seems that the Chicxulub fragment, which left a crater with a diameter of 300 km after hitting the surface of the planet, was the largest. At the beginning of the note, I listed 6 known astroblemes dating back 65 million years. But, of course, these are not all the wounds of the Earth of that period - remember the satellites! And of the 9 large fragments, not all have been identified.

Or rather, not all craters from them have been found.

Our scientists have already described more than once what happens during such a massive cosmic bombardment. A huge amount of dust, gases, water spray and vapors were released into the atmosphere. Powerful earthquakes shook the planet. Awakened volcanoes threw gases, ash, and stones into the atmosphere. Solar luminosity sharply decreased, which led to a decrease in temperature on land and in the oceans, disruption of photosynthesis, and, consequently, to the mass death of plants, planktonic organisms, herbivores and predators.

It is clear that all this lasted more than one month, and maybe even more than one year. Lack of food led first to the death of the most massive animals - herbivorous dinosaurs (diplodocus, brontosaurus, brachiosaurus, etc.) and then the largest predators (tarbosaurs, tyrannosaurs, deinodonts, deinocheiruses, etc.). Of course, they did not die out overnight. Many of them lived to a time quite close to ours. An example is the so-called Ica stones from South America, which features images of people riding dinosaurs. Some scientists estimate the age of these stones at 150-200 thousand years.

“Dino” did not last long underground on its reserves. They began to venture out into a world that had become inhospitable. The question was not about the development of civilization, but about survival. The “Dinos” went wild and did not return to the cities - there was nothing for them to do there, especially since the buildings were, for the most part, in ruins. This is where my “film” ended.

Fiction? Not at all. Hard to believe? Very difficult. But it's time to change your worldview. It's time!

Dinosaurs ruled the world on our planet for 130 million years - 100 times longer than the human race has existed on Earth. And 65 million years ago, dinosaurs went extinct. But 65 million years ago, dinosaurs weren't the only ones who had it bad. Then, in general, difficult times came on Earth. Life on the planet was in mortal danger. Flying reptiles have disappeared. Waterfowl reptiles have become extinct in the oceans, as have shellfish and starfish. Even most of the small animals - plankton - became extinct.

Nobody knows for sure. But there are a great many theories. Most of them suggest that there were some strong changes in the climate of our planet, which damaged many living organisms, not just dinosaurs. The latest and most popular theory claims that dinosaurs and other animal species became extinct due to one terrible universal catastrophe: 65 million years ago, the Earth collided with an asteroid, and a terrible explosion occurred.

Interesting fact: In addition to dinosaurs, flying reptiles and a large number of marine inhabitants became extinct 65 million years ago.

By examining clay deposits in layers of the Earth's crust dated to have been deposited 65 million years ago, scientists have found high levels of iridium in these rocks. Iridium is rarely found on Earth, since during the formation of our planet, iridium, as a heavy element, sank deep underground and is found mainly near the earth's core. Iridium only reaches Earth from space when meteorites and asteroids fall from the sky. Scientists have found iridium in ancient clay deposits around the world. Here is their conclusion: the iridium fell from a cloud of dust that was thrown into the atmosphere when the asteroid collided with the Earth. Here's what could have happened.

Related materials:

How did we know about the existence of dinosaurs?

Dinosaur extinction hypothesis

An asteroid with a diameter of 10 kilometers or more flew from space into the Earth's atmosphere at a speed of at least 100,000 kilometers per hour. Having crashed into the Earth, it formed a crater with a diameter of 160 kilometers. Tons of crushed rocks and soil (a mixture of asteroid and Earth rocks) flew high into the sky from the explosion. Hurricanes arose from the passage of the fireball through the atmosphere and the explosion in the atmosphere, which carried the dust that shot up into the sky throughout the Earth. The sky was clouded with a huge dust cloud. The sun darkened and day became night. The darkness continued for months. The average daily temperature dropped from plus 19 to minus 10 degrees Celsius. The mass death of plants and animals caught in the darkness and cold began.

Following the herbivores, predators that fed on herbivores began to die out. In the end, the cloud sank to the ground, leaving a memory of itself in the form of a large admixture of iridium. Many scientists, however, are skeptical about this theory. Why then, they ask, did birds, crocodiles, turtles, snakes and most mammals survive, as well as insects, shellfish, ocean fish, and many plants? This theory is also questionable because the extinction of dinosaurs occurred very slowly - over millions of years, and not during one giant cataclysm.

The extinction of dinosaurs is one of the most important mysteries of our planet. Why did lizards, which dominated all ecosystems of the Earth for many millions of years, become extinct, and in a relatively short time? Most often, this is blamed on a huge asteroid that fell in the Gulf of Mexico. But, as it turned out, the lizards died not from the darkened sky and acid rain, but from soot from the burnt oil of the gulf. This is the only way to explain why crocodiles, birds and mammals survived the disaster, say the authors of a recent study published in the journal Scientific Reports.

Death or murder?

In world science, the extinction of dinosaurs is most often explained by “catastrophic” hypotheses. Dinosaurs (as well as ammonites and marine reptiles) could have been destroyed by volcanic activity, a meteorite impact, or a supernova explosion near solar system, falling ocean levels. Domestic paleontologists generally adhere to the biosphere version: dinosaurs disappeared gradually - due to the spread of flowering plants and climate cooling. The evolution of plants gave rise to numerous insects. Small mammals (such as rats) fed on them, as well as on plants. Corresponding small-sized predators, also mammals, arose. They could not threaten adult dinosaurs, but the eggs of the lizards became their prey - after all, due to their size, it was extremely difficult for adult dinosaurs to protect future offspring. These and other unfavorable conditions gradually weakened the viability of the lizards, although there was no direct competition between them and mammals.

In Western paleontology, it is precisely “catastrophic” explanations that predominate. The first violin in this was played by the Chicxulub crater - the third largest on the planet (with a diameter of about 180 kilometers). The crater is believed to have been caused by a huge asteroid impact 65 million years ago. In 1980, American physicist Luis Alvarez and his geologist son suggested that the timing of the fall of the Chicxulub asteroid and the extinction of the dinosaurs was not accidental. One of the main arguments in favor of the meteorite hypothesis is the thin layer of clay that everywhere corresponds to the boundary of geological periods. Alvarez pointed to an anomalous concentration of the rare metal iridium (most likely of extraterrestrial origin) in this layer. It is unclear what role Alvarez’s personal experience played in the birth of the dinosaur-killing asteroid hypothesis (he was one of the creators of the atomic bomb), but his version has become very popular over the past 30 years.

The Achilles' heel of the "catastrophic" explanations is that the extinction event lasted several million years and began long before the asteroid impact. So, in 2016, paleontologists estimated that 24 million years before Chicxulub individual species Dinosaurs died out faster than new ones were formed. In some biological groups, this process arose 48-53 million years before the disaster. It's likely that dinosaurs (and other extinct groups like ammonites and sea lizards) were already suffering from long-term processes that are still poorly understood, and the meteorite (or other catastrophe) only accelerated the crisis.

Picture: DETLEV VAN RAVENSWAAY/SCIENCE SOURCE

This objection is now overcome by additional versions: for example, in 2015-2016 about the “double blow” that killed the pangolins. The researchers worked with the Deccan Traps (basalt rocks in western India) - traces of one of the most powerful volcanic eruptions in the history of the Earth. These seismic processes, which released many dangerous volatile compounds into the atmosphere, began 250 thousand years before the fall of the Chicxulub meteorite and continued for half a million years after it (eventually one and a half million cubic kilometers of lava flowed out). These eruptions coincide in time with the fall of Chicxulub. The toxic emissions and volcanic dust that obscured the Sun created a deadly cumulative effect.

Instruments of crime

But why did the fall of an asteroid lead to catastrophic consequences? What were the specific mechanisms of impact on the biosphere? And where does such selectivity come from - dinosaurs died, but not crocodiles, snakes and turtles, ammonites, and not their closest relatives, the nautiluses?

To answer these questions, in April 2016, an offshore expedition: geologists from a drilling platform are trying to drill through the Chicxulub crater at the bottom of the Gulf of Mexico. Rock samples recovered from the sediment can reveal a lot.

Japanese scientists working with bottom sediments of neighboring territories (Haiti) proposed a new explanation: the animals were killed by soot that rose into the atmosphere (there was a lot of it, since Chicxulub fell into the oil-rich Gulf of Mexico). Carbon evidence from corresponding deposits in Canada, Denmark and New Zealand indicates that the asteroid ignited huge amounts of crude oil.

It is generally believed that the impact of Chicxulub caused the planet's atmosphere to become filled with sulfuric acid aerosols. They reflected sunlight - darkness fell, photosynthesis stopped, temperatures dropped (as in a hypothetical nuclear winter), and acid rain began to fall. However, this scenario does not explain the survival of crocodiles, mammals and birds.

Soot emissions seemed like a more realistic scenario to Japanese scientists. They analyzed organic molecules and their isotopes in sediment layers corresponding to the Cretaceous-Paleogene boundary. Soot is easy to identify - it is indicated by polyaromatic hydrocarbons, primarily coronene and benzopyrene.

Soot remains in the stratosphere for many years (even if rain washes it out of the troposphere). Researchers have calculated the impact of emissions on the Earth's climate. Soot actually blocks sunlight, preventing it from reaching the troposphere and the surface of the planet. The water cycle in nature is disrupted, and the amount of precipitation is sharply reduced. If 500 teragrams of soot were released, the light would dim by 50-60 percent, the air temperature at the Earth's surface would drop by 6-9 degrees (for several years), and precipitation would decrease by 40-70 percent. Emissions of 1500-2000 teragrams would increase cooling to 10-16 degrees, and reduce precipitation by 60-80 percent.

Selectivity in choosing a victim

Two unconditional facts established by geologists are a drop in temperature in the Gulf of Mexico and the massive death of land plants from drought in low latitudes (as shown by excavations in Haiti). It was droughts (a decrease in soil moisture by 40-50 percent, if we accept the average emissions scenario) that launched a destructive cycle: the grasses and broad-leaved plants of the tropics dried out, causing soil moisture to drop even more, and so on. The surviving plants were completely eaten up by herbivorous dinosaurs, which led to desertification, the death of large lizards, and then the predators that fed on them. Freshwater crocodiles survived - the basis of their food pyramid was plant detritus, which even in the first critical years of the disaster entered the water. Small mammals, birds, fish, and amphibians, which the crocodiles fed on, also survived.

The final calculations led to the assumption that emissions of 500 teragrams of soot would not have led to the extinction of dinosaurs and ammonites, and the maximum simulated “dose” of soot (2600 teragrams) would have created such a global drought and cooling that all large animals would have died, including crocodile Therefore, the average scenario is closest to the real situation - 1500 teragrams. The accompanying moderate cooling and slowdown of photosynthesis in the World Ocean caused the extinction of ammonites, inoceramas (large bivalves) and planktonic foraminifera, but deep-sea marine organisms were almost unaffected.

Paleontologists emphasize that the Chicxulub disaster was not as terrible as it is described. For example, if the particles released into the air created global darkness for even a few years, photosynthesis would stop, and not only dinosaurs, but also all large land vertebrates, including birds and mammals, would become extinct. Despite the cold and drought, most taxonomic groups of plants and animals at order levels and above survived the crisis. However, scientists note that the Cretaceous-Paleogene extinction event proves that even a short-term catastrophic event can irreversibly change the biosphere - a valuable lesson in an era of global warming.