Earth’s most famous mass extinction event was the giant asteroid that wiped out the dinosaurs 66 million years ago.

It was a severe event, wiping out 76% of all species on the planet. However, two more serious near-apocalypse events occurred in our planet’s history over 4.5 billion years. There have also been five total.

MailOnline investigates the different catastrophes, from the Great Dying to the Kellwasser Cataclysm. It also questions scientists to find out what the most likely cause of a sixth.

1. Ordovician and Silurian extinction 444 Million Years Ago

The Ordovician-Silurian extinction was likely the result of global cooling and lower sea levels, which dramatically impacted the many marine species living in warm, shallow coastal waters

Global cooling and lower sea level likely caused the Ordovician–Silurian extermination of many marine species that live in shallow, warm coastal waters.

The Ordovician–Silurian extermination 

What year was it?

444 Million years ago

What number of species have gone extinct?

85 percent of the Earth’s life is organic 

Was it the reason?

Reduced sea level and global cooling 

It was 444 million years ago that the first recorded extinction occurred. At that time, almost all living things were in the ocean and only a few plants were beginning to emerge on land. 

It was likely due to global cooling and a reduction in sea level, according scientists. This has had a dramatic impact on the marine species that live along the warm coastal waters.

This was the second-worst mass extinction ever recorded by science, and it killed approximately 85 percent of all species.

The world looked very different at the beginning of the Late Ordovician Event. Most of the continents were grouped together in a supercontinent called Gondwana. 

Experts say the global cooling may have been initiated by the rise of North America’s Appalachian Mountains, which in turn sucked carbon dioxide out of the atmosphere, drastically cooled the planet and led to sea levels dropping by hundreds of feet.

2. Late Devonian extermination – 383-359 millions years ago

A large region of volcanic rock now known as the Siberian Traps (pictured) erupted within a couple million years of the Late Devonian extinction

A large region of volcanic rock now known as the Siberian Traps (pictured) erupted within a couple million years of the Late Devonian extinction

Extinction of the Late Devonian

What year was it?

It was 383,000,000 years ago

What number of species have gone extinct?

75 percent of Earth’s total life 

Was it the reason?

Asteroid impacts, volcanism and adaptation of plants

Next up was a period that peaked with the mysterious Kellwasser event.  

A series of pulses that began around 383,000,000 years ago led to the ocean oxygen levels dropping and eventually caused 75% of Earth’s species disappearance over 20 million years.

The worse such pulse was the Kellwasser one, which killed off a number of reef-building creatures.

While it’s not known what caused the extinction, there are several theories. Volcanism, an impact from an asteroid, or even adaptation of plants can all be blamed.

It is due to the fact that a huge area of volcanic rock, now called Siberian Traps, erupted within just a few million years of Kellwasser.

The volcano emitted 240,000 cubic meters of lava into the atmosphere. It also released sulfur dioxide, which could cause acid rain.

Meanwhile, one of Earth’s biggest surviving impact craters – Sweden’s 32-mile-wide Siljan, which can still be found today – formed about 377 million years ago.

Scientists believe plants might also have been responsible. This is because as they adapted many got bigger — and their roots deeper, which would have increased the rate of rock weathering. 

In turn, this caused excess nutrients to flow into the oceans from land, which in turn led to the growth of algae. Dead zone formation also occurred in Earth’s oceans because the algae removed oxygen from them.

Plants were not only culpable but also the spread of trees would also have sucked carbon dioxide out of the atmosphere, scientists say, and this could have caused global cooling. 

3. Permian Triassic extinction 252,000,000 years ago 

A massive volcanic eruption that released chemicals that stripped the Earth of its ozone layer and exposed living organisms to the sun's deadly radiation caused the Permian-Triassic mass extinction

A massive volcanic eruption that released chemicals that stripped the Earth of its ozone layer and exposed living organisms to the sun’s deadly radiation caused the Permian-Triassic mass extinction

Permian-Triassic extermination

What year was it?

252,000,000 years ago

What number of species have gone extinct?

97% of all the life on Earth 

Was it the reason?

An enormous volcanic eruption which released chemical compounds that stripped Earth of its ozone and exposed living organisms the deadly sun radiation. 

But there was more to come. The ‘Great Dying’ took place after the Late Devonian mass extermination.

The End-Permian Mass Extinction was the most significant such event Earth has ever seen and had the greatest impact on our planet’s ecology.

This event took place 252,000,000 years ago. It saw 97% of fossil species disappear for good. 

All life on Earth today is descended from the roughly 10 per cent of animals, plants and microbes that survived the Permian mass extinction.

One theory was that an enormous eruption covered Earth, preventing the sun from shining on its surface.

However, new findings suggest a massive volcanic eruption that ran for almost one million years released a huge reservoir of deadly chemicals into the atmosphere, which in turn stripped the Earth of its ozone layer.

It meant that the one protection Earth’s residents had against sun-damaging UV radiations has been lost. Living organisms are seeing their death rates rise.

4. Triassic-Jurassic Extinction – 201 Million Years Ago

The Late Triassic mass extinction 201m years ago was caused by a large-scale eruption of the Central Atlantic Magmatic Province, which heralded the splitting of the supercontinent Pangaea (left) and the initial opening of what would become the Atlantic Ocean

The mass extinction of the Late Triassic 201m year ago was due to a massive eruption of Central Atlantic Magmatic Province. It caused the division of the supercontinent Pangaea (left), as well as the first opening of what would eventually become the Atlantic Ocean.

Triassic and Jurassic extinction

What year was it?

A mere 201 million years ago

What number of species have gone extinct?

80 percent of the Earth’s life is organic 

Was it the reason?

The acidification of oceans by the eruptioning Central Atlantic Magmatic Province caused an increase in temperatures.

After the ‘Great Dying,’ life continued to prosper and diversify. However, another setback occurred around 201 million Years ago.

The Triassic acidification caused the destruction of up to 80 percent land and marine species.

At the end of that period the Earth warmed an average of between 5 and 11 degrees Fahrenheit, in all likelihood down to the huge amounts of greenhouse gases being thrust into the atmosphere by the Central Atlantic Magmatic Province, which had a lava volume that could cover the US in a quarter-mile of rock.

The oceans were acidified by an increase in carbon dioxide, making it harder for marine animals to make their shells of calcium carbonate.

However, it caused the deaths of many crocodilians who were at the time the dominant vertebrates.

They were replaced by the first dinosaurs, which quickly diversified and began to appear all over the globe.

5. Cretaceous-Paleogene extermination – 66,000,000 years ago

Traditionally, scientists have referred to the 'Big Five' mass extinctions, including the most famous one that brought about the end of the dinosaurs. This was triggered by a meteorite impact, but the other major mass extinctions were caused by phenomena originating on Earth

Scientists have traditionally referred to the “Big Five” mass extinctions as the one that caused the extermination of dinosaurs. The meteorite impact caused this, while the other mass extinctions that occurred were caused by Earth-based phenomena.

Cretaceous-Paleogene Extinction

What year was it?

A mere 66 million years ago

What number of species have gone extinct?

76% of the Earth’s life is a result 

Was it the reason?

An enormous impact of an asteroid 

It is part of the human condition. 

Earth history has seen the disappearance of approximately 98 percent of the species that ever lived on the planet. 

The eradication of dinosaurs is the most famous. It happened 66 millions years ago.

The Chicxulub asteroid, which was about 7.5 miles wide, smashed into Earth in the waters off of what is now Mexico’s Yucatán Peninsula at 45,000 miles an hour.

It left behind a 120-mile wide crater, and it caused tsunamis that ignited wildfires in any area within 900 miles.

Global cooling was also caused by the release of dust and other debris into the atmosphere, which led to ecosystem collapse.

This led to the extinction of 76% of all species in the world.

A sixth extinction – Present day? 

Earth is currently experiencing a biodiversity crisis because of human activities such as deforestation, hunting, and overfishing. It has led to fears that a sixth mass extinction is happening now

The current biodiversity crisis on Earth is caused by human activities like hunting and deforestation. There are fears now that there will be a sixth mass extinction.

According to researchers, the Earth is currently experiencing an’man-made’ sixth mass extermination that includes the “biological annihilation” of wildlife. 

Five mass extinctions have occurred in the history of humanity, and scientists believe that we may be witnessing another.   

According to a 2017 study, a sixth mass extinction has been triggered by a “biological annihilation” of wildlife. This paper claims that the world is now facing a global crisis. 

Scientists believe the cause of the event is humanity’s greedy consumption and willful destruction.

For the last century, two species of vertebrates, those with backbones, have been extinct on an average every other year.

Current estimates are that around 41% of amphibian and 23% of mammal species are in danger of extinction.

An estimated 8.7 Million plant and animal species exist on the planet. Only 86 Percent of terrestrial species, and 91% of marine species have been discovered.

We know of 1,204 mammal and 1,469 birds, 1,215 reptile, 2,100 amphibian, 2,100 amphibian, 215 fish species, and 1,215 bird.

1 414 insects, 2187 molluscs, 732 crustacean and 237 coral are also at risk.

For the 2017 Red List update, more than 25.000 species were assessed and classified as “threatened”. 

It has reached a peak in the risk of death for many invertebrates. 

Scientists believe insects could become extinct in 100 years due to a decline of their population.   

With the Anthropocene, the geological age in which human activity is the predominant influence on the climate and environment, the dawning of mass extinction occurs.


Scientists fear that six of the seven extinctions mentioned above may have occurred right before our eyes.

This threat doesn’t come from outer space. 

It is not tied to the natural forces of nature, such as a huge volcanic eruption or a devastating tsunami.

Our problem is us. 

This warning comes amid concerns that climate change may cause flooding, droughts and wildfires to as many planets as an asteroid or large volcanic eruption.

Earth is currently experiencing a biodiversity crisis, a knock-on effect of the industrial revolution, because of human activities such as deforestation, hunting, and overfishing.

Our planet is also at risk from the spread of diseases and invasive species through human trade and pollution.

This is not all. Research last year showed that poaching, logging, and poaching had pushed 500 amphibians, birds, reptiles, and mammals to the brink.

Species are disappearing at more than 100 times the natural rate, according to researchers led by Professor Gerardo Ceballos of the National University of Mexico in Mexico City. 

He collaborated with Dr Peter Raven from the Missouri Botanical Garden, St Louis, US, to conduct the study. 

Professor Erhlich told MailOnline it was yet more evidence the world is undergoing a sixth mass extinction.

He explained that there are numerous anecdotal evidences and scientific studies showing Earth’s biota well within the sixth mass extinction. 

“Mass extinction” is only one of many existential threats to civilisation. Others include global disruption, climate change, and renewed nuclear weapons race. 

‘Although there is some debate about the causes of the previous five mass extinction events, there’s none at all in the scientific community about the cause of the ongoing sixth — too many people and the richer of them consuming much too much, all exacerbated by gender, racial, and economic inequity.’

He stated previously that the extinction crises is so serious, “whatever is done in the next 10 to fifty years is what will decide the future for humanity.”

Experts say that because of the alarming rate at which species disappear, it is now higher than ever since the time the dinosaurs disappeared. 

The authors added that, if current rates continue as they are, and all species currently designated as critically endangered or endangered go extinct within the next century it could lead to mass extinctions in 240-540 years. 

WWF claimed that within the next ten years, the world will experience the greatest mass extinction since dinosaurs. It is pushing millions of species to the brink of extinction.

It is estimated that there are 8.7 million species of animal and plant species in the Earth. Only 86 percent of terrestrial species, and 91% of marine species have been discovered.

We know of 1,469 mammal and 1,215 bird species, as well as 1,215 reptile and 2,100 amphibian. There are also 2,386 fish species that we consider to be threatened.

At risk: 1,414 insect and 2,187 mollusc; 732 crustacean; 237 coral; 12,505 plants; 33 mushroom; six types of brown alga.

Two species of vertebrates, which are animals that have a bone, die every year on an average over the past 100 years.

Worse, UN reports have shown that over one million species face imminent extinction. Many of these will happen within the next few decades. 

MailOnline was told by Tom Oliver, an University of Reading ecologist: “We are without doubt in the middle of sixth mass extermination of biodiversity.” 

“Evidence is obtained from comparing current extinction rates to the fossil record as well as monitoring systems that track the number of animals and plants around the globe.

Climate change is one of the main drivers that has experts fearing another mass extinction

Experts are concerned about climate change as one reason for another mass extinction.

Historical extinction rates from 1500 to now are 10 to 100 times greater than when humans first existed. Plus, more extinctions are predicted.

‘Declines in the abundance of species often precede extinction and there is evidence of massive abundance declines in many plants and animals — almost 70 per cent  on average globally since 1970 according to credible estimate.’

What will happen to the sixth mass extermination? Can anything be done about it?

Oliver said that if human-driven biodiversity loss eventually equals the five previous mass extinction events, it depends on whether or not the human species is functionally extinct first. And, second, whether we are able to change the course of the human “juggernaut” which is driving the Earth system into crises.

‘Human extinction may seem unlikely, but massive collapses in global population size are possible if we lose the ability to produce food as result of declining soil biodiversity, pollinator losses and uncontrolled diseases — threats which all interact with human-driven climate change. 

“Changing the course the human juggernaut is driving our planet into crisis involves fundamentally altering how you live. What food, work and travel are all important. 

It is necessary to transform nearly all institutions of human society as well the worldviews that they are based on. 

“The most pressing challenge for humanity in the coming decade is to transform our identities and shift our minds towards sustainable living.