Mass extinctions of land animals occur in a cycle of 27 million years

Mass extinctions of land animals, including amphibians, reptiles, mammals and birds, occur once every 27 million years, according to a new study.

American researchers conducted statistical analyzes on the dates of 10 recognized mass extinction events that killed any tetrapod: animals with four limbs.

They detected an underlying “statistically significant” frequency of mass extinctions somewhere in the region of 27.5 million years.

These mass land extinctions line up with major asteroid impacts and devastating volcanic lava spills, known as basalt flood eruptions.

The researchers suggest that they could be dictated by Earth’s orbit in the Milky Way, causing comet showers that have the potential to wipe out all life on our planet.

The most recent mass extinction event the researchers refer to was 7.25 million years ago, suggesting that we don’t expect another for 20 million years.

About 66 million years ago, a giant asteroid struck what is now known as Mexico’s Yucatán Peninsula, causing the sudden extinction of more than 75 percent of Earth’s plant and animal species.


  • Torton-Messin (7.25 million years ago)
  • Eocene-Oligocene (33.9 million years ago)
  • End of the Cretaceous (K / T extinction event, 66 million years ago)
  • End of the Jurassic (145.7 million years ago)
  • End of the Rhaetian (201.3 million years ago)
  • Middle Norian (215 million years ago)
  • End of Carnian (228.5 million years ago)
  • End of the Permian (Great Dying, 251.9 million years ago)
  • End of Guadalupian (259.8 million years ago)
  • End of Sakmarian (290.1 ​​million years)

“ It appears that large body impacts and pulses from internal Earth activity creating a flooded basalt volcanism may be marching at the same rate of 27 million years as extinctions, perhaps at the rate of our orbit in the Galaxy. ” said study author Professor Michael Rampino of New York University.

“These new findings of sudden and coincidental mass extinctions on land and in the oceans, and the common cycle of 26 to 27 million years, lend credence to the idea of ​​periodic global catastrophic events as triggers for extinctions.

In fact, it is already known that three of the massive species killings on land and in the sea occurred at the same time as the three largest impacts of the last 250 million years, each capable of causing a global disaster and resulting in extinctions. ‘

The last vertebrate extinction event, although “relatively small”, Torton-Messin, was 7.25 million years ago, so the next one “could be about 20 million years in the future,” said Professor Rampino. .

250 million years ago, the Permian-Triassic extinction event, also known as the “Great Dying”, wiped out 95% of marine species and 70% of terrestrial species at that time.

British researchers recently concluded that the Great Death was triggered by a huge volcanic eruption in Siberia, which spewed huge amounts of carbon dioxide into the atmosphere.

When the CO2 dissolved in the oceans, they became very acidic and the oxygen level in the water dropped, killing marine life.

Possibly the best-known mass extinction event was 66 million years ago, when 70 percent of all species on land and seas, including dinosaurs, suddenly became extinct.

Pictured is an artist's depiction of fighting Tyrannosaurus rex and Triceratops horridus.  Dinosaurs were wiped out by a mass extinction event about 66 million years ago

Pictured is an artist’s depiction of fighting Tyrannosaurus rex and Triceratops horridus. Dinosaurs were wiped out by a mass extinction event about 66 million years ago

This event, now known as the K / T Extinction Event, was caused by a large asteroid or comet that collided with Earth.

A scientist who spoke to Smithsonian magazine said the asteroid’s debris “turned the air into a furnace and started wildfires around the world,” devastating the environment.

Paleontologists have already known mass extinctions of marine life, in which up to 90 percent of species disappeared, were not random events, but seemed to occur in a cycle of 26 million years.

Turning their attention to the land, the NYU researchers examined the record of mass extinctions of land animals.

They also conducted new statistical analyzes of the extinctions of terrestrial species and showed that those events followed a similar cycle of approximately 27.5 million years, showing that they align with marine extinctions.

It is possible for periodic comet showers to occur in the Solar System every 26 to 30 million years, producing cyclical impacts and causing periodic mass extinctions.

It is possible for periodic comet showers to occur in the Solar System every 26 to 30 million years, producing cyclical impacts and causing periodic mass extinctions.

The ages of impact craters, created by asteroids and comets hitting the Earth’s surface, also cycle.

Astrophysicists hypothesize that periodic comet showers occur in the Solar System every 26 to 30 million years, producing cyclical impacts and resulting in periodic mass extinctions.

The Sun and the planets traverse the crowded midplane of the Milky Way approximately every 30 million years.

“There are two potential effects,” Professor Rampino told MailOnline.

‘Normal matter and dark matter concentrated in the plane have a gravitational effect on loose comets in the Oort Cloud that surrounds the Solar System, causing comet showers and possible ground impacts.

“Another effect is that some of the dark matter can be captured by the Earth, where it becomes concentrated enough to self-annihilate, generating a pulse of heat within the Earth’s core and resulting in volcanic activity.”

Comet showers would cause major impacts on Earth, creating conditions that would stress and potentially kill terrestrial and marine life, including widespread darkness and cold, forest fires, acid rain, and ozone depletion.

Meanwhile, volcanic eruptions would cover vast areas with lava and create severe conditions for life, including brief periods of intense cold, ozone depletion, and increased radiation exposure, as well as acid rain.

The researchers report that eight of the 10 land extinction events are concurrent with known episodes of marine extinction.

The eight coincident mass deaths on land and in the oceans coincided with the times of the flood basalt eruptions.

“The global mass extinctions were apparently caused by the largest cataclysmic impacts and massive volcanism, perhaps sometimes working together,” said Professor Rampino.

In the longer term, the eruptions could lead to lethal greenhouse warming and more acid and less oxygen in the ocean, according to the authors, who published their study in the journal Historical Biology.

Another expert has already warned that humanity today is a mass extinction event as early as the year 2100 due to global warming.

Professor Daniel Rothman of the Massachusetts Institute of Technology came up with a simple mathematical formula to predict when the next mass extinction would occur.

The formula found that by the end of the century the oceans will retain enough carbon to launch a mass extermination of species in the future.

By the year 2100, around 310 gigatons of carbon will have been added to the oceans, a possible ‘tipping point’ for an ecological disaster, according to the 2017 study in Science Advances.

And Sir David Attenborough has already warned that people born today could witness the end of the polar bear in the 2030s, another major pandemic in the 2080s, and a ‘global humanitarian crisis’ in the early 22nd century.


Five times over, the vast majority of the world’s life has gone extinct in what have been called mass extinctions, often associated with giant meteor impacts.

Mass extinction of the end of the Ordovician

The first of the five great traditional extinction events, about 440 million years ago, was probably the second most serious. Virtually all life was in the sea at that time and about 85% of these species disappeared.

Late Devonian mass extinction

About 375-359 million years ago, major environmental changes triggered a protracted extinction event that wiped out major groups of fish and halted the formation of new coral reefs for 100 million years.

Mass extinction of the end of the Permian (the Great Death)

The largest extinction event and the one that most profoundly affected Earth’s ecology took place 252 million years ago. Up to 97% of the species that leave a fossil record disappeared forever.

End of Triassic mass extinction

Dinosaurs first appeared in the Early Triassic, but large amphibians and mammal-like reptiles were the dominant land animals. The rapid mass extinction that occurred 201 million years ago changed that.

End Cretaceous mass extinction

An asteroid crashed into Earth 65 million years ago, and it is often blamed for ending the reign of the dinosaurs.