Finding: Mass Extinctions of Land-Dwelling Animals Occur in 27-Million-Year Cycle

Mass extinctions of land-dwelling animals—including amphibians, reptiles, mammals, and birds—follow a cycle of about 27 million years, coinciding with previously reported mass extinctions of ocean life, according to a new analysis published in the journal Historical Biology.

The study also finds that these mass extinctions align with major asteroid impacts and devastating volcanic outpourings of lava called flood-basalt eruptions—providing potential causes for why the extinctions occurred.

“It seems that large-body impacts and the pulses of internal Earth activity that create flood-basalt volcanism may be marching to the same 27-million-year drumbeat as the extinctions, perhaps paced by our orbit in the Galaxy,” said Michael Rampino, a professor in New York University’s Department of Biology and the study’s lead author.

Sixty-six million years ago, 70 percent of all species on land and in the seas, including the dinosaurs, suddenly went extinct, in the disastrous aftermath of the collision of a large asteroid or comet with the Earth. Subsequently, paleontologists discovered that such mass extinctions of marine life, in which up to 90 percent of species disappeared, were not random events, but seemed to come in a 26-million-year cycle.

In their Historical Biology study, Rampino and co-authors Ken Caldeira of the Carnegie Institution for Science and Yuhong Zhu of NYU’s Center for Data Science, examined the record of mass extinctions of land-dwelling animals and concluded that they coincided with the extinctions of ocean life. They also performed new statistical analyses of the extinctions of land species and demonstrated that those events followed a similar cycle of about 27.5 million years.

What could be causing the periodic mass extinctions on land and in the seas? Mass extinctions are not the only events occurring in cycles: the ages of impact craters—created by asteroids and comets crashing to the Earth’s surface—also follow a cycle aligning with the extinction 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 planets cycle through the crowded mid-plane of the Milky Way Galaxy about every 30 million years. During those times, comet showers are possible, leading to large impacts on the Earth. The impacts can create conditions that would stress and potentially kill off land and marine life, including widespread dark and cold, wildfires, acid rain, and ozone depletion.

“These new findings of coinciding, sudden mass extinctions on land and in the oceans, and of the common 26- to 27-million-year cycle, lend credence to the idea of periodic global catastrophic events as the triggers for the extinctions,” said Rampino. “In fact, three of the mass annihilations of species on land and in the sea are already known to have occurred at the same times as the three largest impacts of the last 250 million years, each capable of causing a global disaster and resulting mass extinctions.”

Lichen-covered flows from the Siberian flood basalts. Photo: Linda Elkins-Tanton

The researchers were surprised to find another possible explanation beyond asteroids for mass extinctions: flood-basalt eruptions, or giant volcanic eruptions that cover vast areas with lava. All eight of the coinciding mass die-offs on land and in the oceans matched times of flood-basalt eruptions. These eruptions also would have created severe conditions for life, including brief periods of intense cold, acid rain, and ozone destruction and increased radiation; longer term, eruptions could lead to lethal greenhouse heating and more acid and less oxygen in the ocean.

“The global mass extinctions were apparently caused by the largest cataclysmic impacts and massive volcanism, perhaps sometimes working in concert,” added Rampino.

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Brian Pratt
December 12, 2020 10:11 am

Photograph is of the Deccan Traps, India.

Reply to  Brian Pratt
December 12, 2020 2:04 pm

Knowing that as solar orbit moves up and down through galactic plane and areas of higher or lower cosmic dust density and cosmic radiation it is also possible that in the extreme case of either life on earth might be severely affected.
comment image?

Reply to  Brian Pratt
December 13, 2020 6:10 am
“(…) the Indian Plate split from Madagascar. It began moving north, at about 20 centimetres (7.9 in) per year,[9] and is believed to have begun colliding with Asia as early as 55 million years ago,[11] in the Eocene epoch of the Cenozoic. However, some authors suggest the collision between India and Eurasia occurred much later, around 35 million years ago.”
“(…) have a volume of c. 1,000,000 km3 (200,000 cu mi).[2] Originally, the Deccan Traps may have covered c. 1,500,000 km2 (600,000 sq mi),[3] with a correspondingly larger original volume. ”

So the obvious question is:
Where was the Deccan Traps when the Deccan Traps happened? How much heat was released into our oceans and how many meters of ocean depth would that volcanic release, increase the temperature to a lethal level (40 degrees C) to?


John Tillman
Reply to  Oddgeir
December 14, 2020 1:29 am

The Deccan Traps erupted when the Indian Plate passed over the Reunion Island Hotspot.

December 12, 2020 10:12 am

Anthony, thanks for this post!


PS: Just in case I don’t see another one of your posts between then and now: Have a Merry Christmas and a Happy New Year!!!!!

PPS: I’ve got an idea for a Friday Funny post. It’s short and sweet and I’ll try to upload it here on Friday the 18th.

Reply to  Bob Tisdale
December 12, 2020 12:22 pm

Ich bin immer noch ein Slosher!

Merry Christmas, Bob.

John Tillman
December 12, 2020 10:17 am

So we’ve got about 12 million years left, not just 12 or less.

Walter Horstingg
Reply to  John Tillman
December 12, 2020 10:47 am


Last one was 12,800 years ago Mega Fauna extiction in the Western Hemisphere.

John Tillman
Reply to  Walter Horstingg
December 12, 2020 11:34 am

That doesn’t fit the schedule because caused by humans. And vast majority of land animal species survived.

Reply to  John Tillman
December 12, 2020 12:16 pm

Claiming it was caused by humans in just revisionist misanthropic history but agreed it was not on a scale with mass extinctions being discussed.

I’m wondering how many data points they have to declare the supposed “cycle”. I see no graph , not table of dates and no DATA.

On the basis that any half respectable scientist would show his evidence when making such a claim, I’ll conclude this is yet more pseudo-science.

My guess is that they have about four dots and one is close to being in antiphase with the claimed cycle so they use a graph with broad vertical bands to help the reader see a non existent periodicity.

I’m beyond caring about investigating spacious claims. If an author has something lets see without turning it into a paper chase.

Reply to  Greg
December 12, 2020 12:28 pm

OK, it seems they have 10 dates and four “craters”.

On the ten data points they did a spectral analysis ( LOL ).

John Tillman
Reply to  Greg
December 12, 2020 1:23 pm

The evidence for humans’ having caused megafaunal extinctions is overwhelming. It’s not just the repeated coincidences, but actual paleological and archaeological finds.

Humans arrive in Australia, and megafauna which have survived numerous glacial-interglacial cycles rapidly go extinct.

Modern humans arrive in northern Eurasia, and megafauna which have survived numerous glacial-interglacial cycles rapidly go extinct.

Modern humans arrive in the Americas, and megafauna which have survived numerous glacial-interglacial cycles rapidly go extinct. When we get to Caribbean islands, same thing.

Modern humans arrive on remote oceanic islands, and megafauna there rapidly go extinct. On island after island. Madagascar. Hawaii. New Zealand. Mauritius. And often not so megafauna.

John Tillman
Reply to  Greg
December 12, 2020 2:14 pm


Reply to  Greg
December 12, 2020 5:46 pm

We’ve been trying to wipe out the whales for centuries.

John Tillman
Reply to  Greg
December 12, 2020 6:06 pm

We succeeded with some species and came close with others:

Reply to  Greg
December 13, 2020 3:48 pm

Humans didn’t have to be bloodthirsty fauna killers. If woolly mammoths have one offspring every 5 years like elephants, hunters only have to kill one every 4 years to extinct them in a few generations. It could even be disease on the fleas of the dogs that humans brought with them, still a human arrival issue. It is unlikely a hunter would risk his life downing a huge creature unless the tribe is really hungry and short of rabbits, fish and berries….

John Tillman
Reply to  Greg
December 14, 2020 1:38 am


You get resources from mammoths which rabbits and other lean game don’t provide, such as fat, heavy hides and tusks. Not to mention mountains of meat which, when smoked, can feed the clan through winter.

We know that Clovis hunters did indeed k!ll mammoths. Their technology was developed to take big game. As with 19th century bison hunters, cows were probably preferred.

Had petroleum refining not been developed, more whale species would have been wiped out.

Reply to  Greg
December 14, 2020 7:32 am

John, I’m just saying humans didn’t necessarily have to undertake wanton specicide….but the near extinction of buffalo, for example, is clear proof….

John Tillman
Reply to  Walter Horstingg
December 12, 2020 11:44 am

Nor were the Carolina Bays caused by an impact.

Nor were the megafaunal extinctions, which occurred over tens of thousands of years in Australia, Eurasia and the Americas. When people reached remote oceanic islands in historic times, more large land animals were wiped out.

The last North American megafaunal species to go extinct did so on Caribbean islands, long after the Younger Dryas.

Antillean ground sloths survived until possibly 1550 BC. Radiocarbon dating suggests an age between 2819 and 2660 BC for the last occurrence of Megalocnus in Cuba. Ground sloths had been extinct on the mainland of North and South America for 10,000 years or more, so they lasted five to six thousand years longer in the Caribbean than on the continents, which correlates with the later colonization of this area by humans.

Reply to  John Tillman
December 12, 2020 12:25 pm

But what of Megalochness in Scotland? Are they extinct, too?

John Tillman
Reply to  jorgekafkazar
December 12, 2020 1:55 pm

To become extinct, you first have to have existed.

Martin Cornell
Reply to  Walter Horstingg
December 12, 2020 4:13 pm

How would such galactic orientation and mass lava flows be selective for mega fauna?

Paul of Alexandria
Reply to  Martin Cornell
December 13, 2020 10:31 am

Because they eat so much. The mass extinctions kill off the plants and the large herbivores, which kills off the large carnivores. The smaller animals can scrounge a lot better.

Bryan A
Reply to  Walter Horstingg
December 12, 2020 8:55 pm

Sorry, the last one was CC Science circa 1988
That was the last great Math Extinction
And it has been spiraling downwards ever since

Reply to  Bryan A
December 13, 2020 8:46 am

And now that so many can hardly count, the marxists use numbers to screw/completely fool them.

Gordon A. Dressler
Reply to  John Tillman
December 12, 2020 10:57 am

Maybe . . . maybe not. I have supreme faith that the ignorance and stupidity of most humans can override nature’s timeline(s). 🙂

william Johnston
Reply to  Gordon A. Dressler
December 12, 2020 1:51 pm

Albert Einstein. Two things are infinite. The universe and human stupidity. And I am not sure about the universe.

Gordon A. Dressler
Reply to  william Johnston
December 12, 2020 6:20 pm

Thank you, WJ.

Here’s one back at ya: “The two most common things in the universe are hydrogen and stupidity.”—attributed to writer Harlan Ellison

Reply to  Gordon A. Dressler
December 13, 2020 8:48 am

Air-heads are indeed common.

Reply to  John Tillman
December 12, 2020 12:56 pm

the Sun has a micro nova every 12-25 thousand years and we are due. At the 3 minute mark–

Reply to  homerd
December 12, 2020 2:47 pm

No it doesn’t, surprised? Clicking on this link will waste several minutes of your life.

Reply to  Loydo
December 12, 2020 5:50 pm

Why would I believe anything you say Loydo? Are you the keeper of all knowledge?

Nick Graves
Reply to  rbabcock
December 13, 2020 5:27 am

A fount of all knowledge 😉

Richard (the cynical one)
Reply to  John Tillman
December 12, 2020 7:17 pm

Then the warmists will get to experience climate change at its most dramatic. Finally the will be vindicated! Hang in there, Loydo. Have patience, Griff. You will get the last laugh.

Reply to  John Tillman
December 12, 2020 12:57 pm

that is every 12-15 thousand

John Tillman
Reply to  homerd
December 12, 2020 2:12 pm

Phanerozoic’s 541 million years divided by 20 events equals 27.05 million year intervals on average.

Dunno where you got 12-15 thousand.

Bryan A
Reply to  John Tillman
December 12, 2020 9:06 pm

Dino extinction +/- 66mya
Next predicted event would be +/- 39mya
Then it would be +/- 12mya
With the next due in +15my
What mass extinction events happened 12mya and 39mya?

Reply to  Bryan A
December 13, 2020 7:06 am

There was a minor extinction event at the end of the Eocene, some 34 Ma. Multiple impact craters around that time – Chesapeake and Popogai and a flood basalt in the Afar.

The entire discussion reminds me of the old Nemesis proposal from 1984 when a red / brown dwarf called Nemesis would get close enough to disrupt the Oort Cloud, creating a comet storm. Problem is that something that far away won’t stay gravitationally bound to the sun for a long time.

The other problem is that stars periodically get pretty close and their Oort Clouds and the solar system’s Oort Clouds overlap / interact / trade members and disrupt one another. Van Maanen’s star (a white dwarf) is thought to be the last one 15,000 years ago. Next up appears to be Hip 85605 240 – 470 ky from now. This happens far to often to show a 27 Ma periodicity. Cheers –

John Tillman
Reply to  Bryan A
December 14, 2020 3:38 pm

Please see Eocene-Oligocene and mid-Miocene extinctions discussed below. It’s not just the five mass extinction events.

Mike McHenry
December 12, 2020 10:25 am

This sounds like a redo of the work done by Raup and Sepkoski in the 1980’s

December 12, 2020 10:39 am

This sort of cycle analysis is usually catnip for Willis E. I expect his post to appear sometime next week.

John Tillman
Reply to  Pouncer
December 12, 2020 10:56 am

Shaviv and Veizer (2003) proposed a ~150 million year ice age cycle in the Phanerozoic, based upon the solar system’s orbit of the galactic barycenter:

Continental ice sheets didn’t form during the Mesozoic Ice House interval, given the generally balmy conditions of that era, but it did get colder in the Late Jurassic. Feathered dinosuars proliferated in that epoch and the Early Cretaceous.

Ed Zuiderwijk
Reply to  John Tillman
December 12, 2020 11:39 am

Why do they always add ‘ozone depletion’ to the list? Are extreme cold and acid rain not enough? That radiation thingy is just a red herring to me.

John Tillman
Reply to  Ed Zuiderwijk
December 12, 2020 11:45 am

Yes, even though ozone depletion over Antarctica is now known to occur naturally, humans are still blamed. Convenient lies die hard.

Reply to  Ed Zuiderwijk
December 12, 2020 12:30 pm

You might say the same about ‘lethal greenhouse heating.’ Are cataclysmic eruptions and mammoth meteoritic impacts not enough? Forget the turtles; it’s red herrings all the way down.

December 12, 2020 10:42 am

So much for worrying about Climate change, huh? Looks as if mass extinction even overshadows the next Ice Age as something to scare the Hades out of people! We mortal earth-creatures have a LOT more to worry about! Of course, this might not be a real problem for the next, oh say, 5-10 million years. Or more.

Bruce Cobb
December 12, 2020 10:50 am

“lethal greenhouse heating”

Reply to  Bruce Cobb
December 12, 2020 12:32 pm

That was my reaction, too. You’ve expressed it more succinctly.

Peta of Newark
December 12, 2020 11:10 am

Just as well ‘something’ happens or the none of us would be here.

The ‘Technical Term’ might be Ploughing or perhaps ‘Tillage’

These events stir up large amounts of new rock which is then eroded by slightly acidic, thanks to CO2, soil and dirt that feed plants.

Else Earth would by now be an almost identical twin to Mars.

Re: The Deccan Traps = now = The Bread Basket of India.
And why folks like to live on the slopes of Vesuvius, despite the ever present danger of it going off again and taking itself plus 5 million folks off the map
Or why so many tomatoes are grown on the (volcanic) Canary Isles, tomatoes being closely related to the tobacco plant – it being THE hungriest plant there ever was. (2nd only to triffids I’d imagine)

Re the Nightshades – there are NO free lunches, it takes a lot of nutritional-grunt to create something as hideous as the Alkaloid poisons.
Yet we lap them up like our lives depended – witness the Mediterranean Diet, chock full of poison even before wine is added into the mix.
Princess Nut Nuts might be the only sane one amongst us.
Ugh – wotta a thort!!!

Reply to  Peta of Newark
December 12, 2020 1:08 pm

Yet the Mediterranean Diet is clearly linked to longevity. In fact, tomatoes have a high concentration of lycopene, an antioxidant that has been shown to reduce the risk of the two largest morbidities; cancer and cardiovascular disease. They also help to prevent macular degeneration.

While it’s true that tomatoes are members of the nightshade family, they don’t produce the toxic alkaloid solanine, they produce a far less toxic substance called tomatine and ripe red tomatoes have very low doses of it. Even green tomatoes are fine – a person would have to eat lots of green tomatoes to give them a tummy-ache.

Seems like you just made up that stuff about tomatoes being poison – they’re not, in fact they’re a healthy food. And the Canary Islands? While they do grow a lot of them there, the Canary Islands aren’t where Europe gets most of their tomatoes and aren’t even in the top 7 of tomato producing regions throughout the world. Tomato growing doesn’t need volcanic soil.

John Tillman
Reply to  Meab
December 12, 2020 1:52 pm

Tomato production – 2018
Country Production
(millions of tonnes)
China 61.5
India 19.4
United States 12.6
Turkey 12.2
Egypt 6.6
World 182.3
Source: FAOSTAT of the United Nations[54]

Tom in Florida
Reply to  Meab
December 13, 2020 5:24 am

” Tomato growing doesn’t need volcanic soil.”
But San Marzano tomatoes are the best, grown on the slopes of Mt Vesuvius. Just be sure that the “DOP”emblem is on the label to enure authenticity. These are the only tomatoes one should use for pizza. Do not over season them. Just just crush them up, add some olive oil and salt, and let the natural sweet flavor come through. No need to even cook the mixture for pizza, it will cook in your 500 degree F oven.

Paul of Alexandria
Reply to  Meab
December 13, 2020 10:36 am

Tomatoes aren’t poisonous, but they are related to night-shade and when they were first introduced to Europe in the 1500’s people thought that they were poisonous. I forget exactly who it was, but one of the early explorers astounded everyone by publicly eating a tomato.

December 12, 2020 11:13 am

Or the aliens stopped making fossils on a few occasions, 27 million years apart, due to mandatory holidays and a labor strike. Slightly more seriously, is it just possible that the theory requiring multiple mass extinctions is based on an apparent coincidence in an imperfect record?

December 12, 2020 11:26 am

Somewhat off topic: The alarmists don’t seem to believe that critters can adapt to changing conditions. Here’s a paper describing how spiders build nests in the international space station.

I realize not much can withstand a mass extinction but the thought of space spiders amuses me.

John Tillman
Reply to  commieBob
December 12, 2020 11:32 am

The space spiders can ranch tardigrades.

Ed Zuiderwijk
Reply to  commieBob
December 12, 2020 11:40 am

Pigs in space were more fun!

Peter Fraser
Reply to  commieBob
December 12, 2020 11:51 am

Never under estimate spiders’ survival ability. I have observed numerous spiders living happily in amongst oyster growing racks where they are submerged by estuarine seawater for eight of the twelve hours of each tidal cycle

[please make sure your email is correct or you will keep getting flagged by moderation filter-mod]

Reply to  commieBob
December 13, 2020 9:29 am

the thought of space spiders amuses me.

I dunno, the space spiders in Heinlein’s Starship Troopers were pretty nasty.

Rud Istvan
December 12, 2020 11:38 am

Color me very skeptical. The Chicxulub impact K-T mass extinction was 66mya. If this ‘new’ theory were correct, there should have been one somewhere between 36 and 40mya. There wasn’t. The closest is the mild ‘stepwise’ Eocene/Oligocene event about 33mya. This took place over about 2 million years (hence stepwise), and involved only some marine organisms, nothing on land. Thought caused by changed ocean currents as Antartica reached the south pole.

There also have been another something like 10-14mya. There wasn’t.

John Tillman
Reply to  Rud Istvan
December 12, 2020 12:09 pm

The Chesapeake Bay-creating impact was about 35.5 Ma. The big Siberian Popigal Crater is around 35 million years old. They comport well with the Eocene-Oligocene extinction event.

Extinctions don’t all happen in one day. In fact most of them last a long time.

The Mid-Miocene Disruption, c. 14 Ma, is associated with the Columbia River flood basalts, although other causes have also been suggested:,Langhian%20stage%20of%20the%20Miocene.

John Tillman
Reply to  John Tillman
December 12, 2020 12:25 pm

Not that I am convinced that the Chesapeake and Popigal impacts contributed significantly to the E-O EE. Global cooling resulting from formation of deep channels in the Southern Ocean between Antarctica and South America and Australia, leading to ice sheet formation, is IMO more important.

Paul of Alexandria
Reply to  Rud Istvan
December 13, 2020 10:43 am

It all depends on how large the asteroids/comets happen to be. All it takes is one 8-mile diameter rock to ruin an ecosystem. On the other hand, a few 1-mile wide rocks will ruin localities but wouldn’t necessarily have a planetary effect, especially if they’re spread out in time.

lower case fred
Reply to  Rud Istvan
December 13, 2020 6:31 pm

The theory does not say that an impact must happen, only that conditions make one more likely.

Absence of proof is not proof of absence.

People “win” at Russian Roulette sometimes – statistically 5 times out of 6 with a 6-shooter.

etc., etc.

Keith Peregrine
December 12, 2020 11:45 am

Much appreciated. Glad to finally read something not linked to global warming!

Steve Case
December 12, 2020 11:56 am

Off Topic but appropriate:

UN urges world leaders to declare ‘climate emergency’
United Nations chief Antonio Guterres described the situation as “dramatic” and urged countries to take drastic action. A virtual conference is taking place to mark five years since the Paris climate accord.

Joel O'Bryan
Reply to  Steve Case
December 12, 2020 12:03 pm

With the COVID scare running on fumes, they need something to keep the people frightened and under control.

Joel O'Bryan
December 12, 2020 12:00 pm

I think Willis would enjoy looking at the author’s use of spectral analysis.
Looks pretty shaky to me. The 18 (17 actually) events used:

Table 1. Ages (with approximate error bars) (Ogg et al. 2016) of 10 extinction episodes of non-marine tetrapods (asterisks), with % extinction of families where available. Fourteen LIPs events, 9 stratigraphic volcanogenic mercury anomalies, the four largest impact craters (diameters ≥100 km), and 13 marine-extinction episodes, with % extinction of families (Raup and Sepkoski 1986; Rampino et al. 2019). CRB = Columbia River Basalts; NAIP = North Atlantic Igneous Province; CAMP = Central Atlantic Magmatic Province; PETM = Palaeocene-Eocene Thermal Maximum

Non-Marine Tetrapod Marine Extinctions
Extinction (% families) Age (Ma) LIPs Age (Ma). Hg Anomaly Crater (Age Ma) (Ma) (% families)
*Torton.-Messin.(2%) 7.25 ________ ______ ____ __________ ______
____________ _____ ________ _______ ____ __________ 11.6 (1%)
____________ _____ CRB 16.6 ± 0.03 ____ __________ __________
____________ _____ Ethiopian 30.4 ± 0.4 ____ _____ _____
*Eocene-Oligocene (8%) 33.9 ± 0.2 ________ ____ ____ ______ __________
____________ _________ ________ ____ ____ Popigai 35.7 ± 0.2 36 (3%)
____________ _________ NAIP 55.6 ± 0.3
61.9 ± 0.3 ____ _______ (PETM)
*end-Cretaceous (14%) 66.04 ± 0.05 Deccan 66.3 ± 0.03 Yes Chicxulub 66.0 ± 0.37. 66 (15%)
_____________ ________ Caribbean 93.6 ± 1.8 Yes _______ 93.9 (5%)
_____________ _________ Ontong Java 124.3 ± 1.8 Yes _______ 124 (3%)
_____________ _________ Paranå 134.3 ± 0.8 Yes _______ _______
*end-Jurassic 145.7 ± 0.8 Shatsky Rise 144.4 ± 1.0 ____ Morokweng 145.2 ± 0.8 145.7 (6%)
___________ _________ Karoo/Ferrar 183.7 ± 0.5 Yes _________. 183.7 (5%)
*end-Rhaetian (22%) 201.36 ± 0.17 CAMP 201.5 ± 0.05 Yes __________ 201.4 (13%)
*mid-Norian 215 ± 0.25 Angayucham 214 ± 7 ____ Manicouagan 214.6 ± 0.05 215 (7%)
*end-Carnian 228.5 ± 0.25 Wrangellia 230 ± 2 ____ ___________ 228.5 (5%)
*end-Permian (49%) 251.90 ± 0.024 Siberian 251.9 ± 0.07 Yes ___________ 251.9 (35%)
*end-Guadalupian 259.8 ± 0.5 Emeishan 259.8 ± 0.5 Yes ___________ 259.8 (15%)
*end-Sakmarian (58%) 290.1 ± 0.2 Panjal 289 ± 3 Yes __________ 290.1 (5%?)

Really they have 17 events (not 18) over 289 my. They power spectrum spikes all over the record. 27.5 my is the strongest. 17 in 289 is 17 my/event average. They have their strongest power spectrum spike at 27.5 my. Looks like aliasing to me. Pretty weak evidence IMO.

Jean Parisot
Reply to  Joel O'Bryan
December 12, 2020 1:56 pm

Whats the population scaling of the megafauna involved? Does it just take that long for a large enough population to buildup that random events look like a cycle. The same event a short time later not showing up in the fossil records.

James Walter
December 12, 2020 12:25 pm

Consider the extinction of the dinosaurs, ~66 million years ago. Before that time, gravity was weak enough (i.e., probably, the mass of earth was small enough) to allow dinosaurs to walk (the bone mass/density problem with today’s gravity would not have allowed dinosaurs to stand, much less run). Perhaps huge debris showers of asteroids, meteors, etc. added significant mass to the earth 66 million years ago, as well as the other mass extinctions/flood-basalt/meteor showers 39 and 12 million years ago?

John Tillman
Reply to  James Walter
December 12, 2020 12:38 pm

Sauropods could walk under present Earth gravity. Mesozoic gravity was virtually identical to now.

While the heaviest land animals, they were relatively light for their size, thanks to their bird-like anatomy.

Reply to  John Tillman
December 12, 2020 2:43 pm

And their bird-like breathing, one-way airflow through lungs 10x more efficient than tidal mammalian lung.

John Tillman
Reply to  Phil Salmon
December 12, 2020 3:01 pm

Yup. Plus their bones made lightweight by the air sacs used in their breathing system.

Their bones are so flimsy that sauropod skulls are rarely preserved.

Joel O'Bryan
Reply to  James Walter
December 12, 2020 1:00 pm

Thanks for the chuckle James. 🤣😂

or maybe the atmosphere was so thick and heavy during the Age of dinosaurs they were buoyantly suspended???

or maybe dinosaurs were made of aerogel??

Reply to  James Walter
December 12, 2020 1:21 pm

James.. If you have a ‘mass’ extinction.. surely things get lighter. 😉

Reply to  James Walter
December 12, 2020 1:35 pm

If enough material had fallen onto the earth to raise it’s gravity even by 0.1%, the entire surface of the earth would have been molten for millions of years.

I don’t know where you get the notion that dinosaurs couldn’t walk upright under today’s gravity conditions. Nothing could be further from the truth.

John Tillman
Reply to  MarkW
December 12, 2020 2:19 pm

A member of the elephant family which went extinct possibly only 24 Ka weighed around 20 tonnes, rivaling the giant hornless rhinos of the Oligocene.

Mass estimates for the largest sauropods keep coming down, and now are around 50 tonnes rather than earlier guesses of 100 tonnes, based upon mammalian rather than avian models. Possibly even less.

John Tillman
Reply to  MarkW
December 12, 2020 2:19 pm
James Walter
Reply to  MarkW
December 13, 2020 1:56 am

Please give me your proof that the largest Dinosaurs had no problem standing.

John Tillman
Reply to  James Walter
December 14, 2020 1:56 am

Dinosaur bone structure, reproduction and growth rates show that even the largest stood and walked without supports.

The biggest Cenozoic mammals, as heavy as all but the largest sauropods, needed no support. The most recent 20-tonner went extinct just 24,000 years ago.

Reply to  James Walter
December 12, 2020 4:08 pm

Perhaps dinosaurs have undergone a mass extinction because they were as dense as the Flintstones ?

Bob boder
Reply to  James Walter
December 13, 2020 3:56 am


December 12, 2020 12:42 pm

More of the retentive obsession to reduce every event on earth to a clockwork celestial cycle of some sort. Nonsense.

Mass extinctions arise at various times determined by the chaotic interaction of continental movement and tectonic-volcanic events, astronomic rare events such as asteroid impacts and possibly nearby supernova explosions, and resulting outbreaks of marine anoxia.

Here’s the real data – no cycles needed

John Tillman
Reply to  Phil Salmon
December 12, 2020 1:33 pm

Impacts and flood basalts aren’t the only causes of increased extinction rates above background.

William Astley
Reply to  Phil Salmon
December 12, 2020 2:23 pm

Your comment/beliefs are not correct. Due to the climate wars, it is a fact that there is a super big hidden mystery in geology/climate science which is the mother of all paradoxes.

In fact, the earth paradoxes the most important problem in hard science. A paradox is something that is happening that has no physical explanation. The physical explanation to cause abrupt cyclic changes to the geomagnetic field will require a Universe changing explanation. How is that possible?

Of course there must be observations in Astronomy that could and do explain what is happening on the earth. Logically everything is connected.

It is an observational fact, that the geomagnetic magnetic field and the occurrence of periods of large, volcanic activity are both cyclic and have the same periodicity and a common forcing function.
41,000-year cycle in the Earth’s tilt matches up with peak volcanic activity

After pulling together all the eruptions they identified over the past million years, they analyzed the data for cyclical patterns.

They found cycles of the same length as the orbital cycles that affect climate—particularly the 41,000-year cycle in Earth’s tilt, which shows up most prominently.

To ensure this wasn’t a fluke, they artificially generated 100,000 random data sets. Fewer than 1 percent of the data sets contained a signal as strong as the 41,000-year pattern in the actual data.

Bipolar cyclic volcanic activity requires a forcing function that affects both hemispheres. There is no such forcing function currently in geology.

Bipolar correlation of volcanism with millennial climate change
Analyzing data from our optical dust logger, we find that volcanic ash layers from the Siple Dome (Antarctica) borehole are simultaneous (with >99% rejection of the null hypothesis) with the onset of millennium-timescale cooling recorded at Greenland Ice Sheet Project 2 (GISP2; Greenland). These data are the best evidence yet for a causal connection between volcanism and millennial climate change and lead to possibilities of a direct causal relationship.
The Role of Explosive Volcanism During the Cool Maunder Minimum

There is 100,000 year cycle in the geomagnetic field intensity. The geomagnetic field intensity is greatest when the earth’s orbit is most eccentric.

A relative paleointensity record of the geomagnetic field since 1.6 Ma from the North Pacific

Coherent variations in the relative paleointensity despite incoherent changes in the magnetic properties suggest that rock-magnetic contamination to the relative paleointensity is small, if any, and the ∼100 kyr period in the relative paleointensity records would reflect the geomagnetic field behavior.

Is the geodynamo process intrinsically unstable?
Recent palaeomagnetic studies suggest that excursions of the geomagnetic field, during which the intensity drops suddenly by a factor of 5 to 10 and the local direction changes dramatically, are more common than previously expected. The `normal’ state of the geomagnetic field, dominated by an axial dipole, seems to be interrupted every 30 to 100 kyr; it may not therefore be as stable as we thought.

And there is more…. Five years ago, it was discovered that the frequency of mid-ocean ridge earthquakes, all over the world are changing at the same time in real time.

And the sudden unexplained increase in volcanic activity all over the world at mid-ocean ridges where the ocean floor is being pushed apart ….. is two two years in advance of El Nino events which is odd as some that follows is caused by… which makes sense. Mid ocean volcanic release does change ocean surface properties. But what is causing the sudden changes in mid-ocean ridge earthquake frequency all over the world? What causes the mid-ocean ridge earthquakes?

New evidence for extraordinary rapid change of geomagnetic field during a reversal

Here is another supporting anomaly. Five geologically and regionally independent (different magma chambers) Auckland volcanoes that simultaneously erupt and capture a geomagnetic excursion.

Weird that the very rare geomagnetic excursion occurs at the same time five independent volcanoes all erupt to capture the geomagnetic excursion.

Geomagnetic excursion captured by multiple volcanoes in a monogenetic field

Paleoclimatic context of geomagnetic dipole lows and excursions in the Brunhes, clue for an orbital influence on the geodynamo?

Reply to  William Astley
December 12, 2020 7:11 pm

Has anyone looked at the Earth AC magnetic field and telluric eddy losses in the mantle?

Reply to  William Astley
December 12, 2020 9:07 pm

Care to come up with a mechanism to link the earth’s orbit to vulcanism?

Reply to  William Astley
December 13, 2020 5:40 am

I am amazed that the Earth’s rapidly declining magnetic field doesn’t get more attention. In my view, this is by far the most important change that could have devastating impact on the Earth’s climate. I’m curious if magnetic field strength feeds into climate models. With the decline of 5% per decade, it’s a big deal. I just don’t understand how scientist can ignore the impact of increases in high energy particles hitting the earth as the magnetic field wanes. Good post.

Phil Salmon
Reply to  Phil Salmon
December 12, 2020 5:13 pm

I don’t deny Milankovitch cycles and have frequently defended them when others do. It’s also common knowledge that earth’s magnetic field periodically reverses, that’s how Wegener’s continental drift was confirmed.

And we don’t know that much about the spinning iron at the earth’s center. But with magnetic fields you and Vuk need to be careful not to confuse cause with effect.

William Astley
Reply to  Phil Salmon
December 12, 2020 6:52 pm

What I provided was multiple independent observations that prove the geomagnetic field is changing periodicity and that it is changing very, very fast…

… And the changes are very large in magnitude.

Milankovitch theory is the changes to summer solar insolation (amount of sunlight) at 65N cause the glacial/interglacial cycle. That theory is not correct.

The change in geomagnetic field strength and orientation appears to be the primarily large driving factor of the earth’s climate.

And at this time, geology has not solved the puzzle what causes the geomagnetic field and what causes it to change.

Different subject. The continental plates and oceanic plates do not ‘drift’. Geology does not have a force to move the plates that sit on top the plastic mantle. That is a big mystery. No answer.

The plates are pushed by something and geology has found evidence that there are 1000 and 1000 and 1000 of tube like structures that intersect near the crust at 200 miles below the surface and then go down to the core of the planet.

These tube like structures were discovered by their waves they reflected when large earthquakes occur on the earth, about 5 years ago.

These core to crust ‘tubes’ transmit force and liquid CH4 from the earth’s liquid core as the liquid core of the earth solidifies and it extrudes the liquid CH4. The liquid methane at high temperature reacts with elements in the mantle which forms a sheath about the tube which keeps the CH4 in the tube.

It is the CH4 in the tubes that push the ocean plates apart at the ocean ridges. The pushing of the ocean crust at the ocean ridges creates long cracks in the ocean floor that are parallel to the spreading ocean plate.

The core of the earth is believed to have started to solidifying roughly a billion years ago.

The ‘tubes’ form as the elements hydrogen and carbon have been removed from the mantel when the Mars size object impacted the earth roughly 100 million years after it was formed and by the descent of heavy metals into the core. The ‘tube’ is required to contain the force and the CH4 to enable it to reach the surface of the planet.

As noted in the paper below, increase in mid-ocean seismic activity closely correlates with ocean temperature changes for the entire period.

Two previous studies, The Correlation of Seismic Activity and Recent Global Warming (CSARGW) and the Correlation of Seismic Activity and Recent Global Warming: 2016 Update (CSARGW16), documented a high correlation between mid-ocean seismic activity and global temperatures from 1979 to 2016 [1,2].

As detailed in those studies, increasing seismic activity in these submarine volcanic complexes is a proxy indicator of heightened underwater geothermal flux, a forcing mechanism that destabilizes the overlying water column.

This forcing accelerates the thermohaline circulation while enhancing thermobaric convection [3-6]. This, in turn, results in increased heat transport into the Arctic (i.e., the “Arctic Amplification”), a prominent feature of earth’s recent warming [7-9]. .<

Reply to  William Astley
December 12, 2020 9:12 pm

I’ve read some really stupid thing in my years on this planet, but this post takes the prize as one of the dumbest.

There is no CH4 in the core.
1) It couldn’t survive the temperatures down there.
2) It would have come to the surface back when the whole planet was molten.

Paul of Alexandria
Reply to  William Astley
December 13, 2020 10:48 am

Plate tectonics is driven by convection currents in the mantle. Simple as that.

Reply to  Paul of Alexandria
December 13, 2020 12:13 pm

Convection in the mantle varies due change in the gravity pull effect from the very slow differential rotation of the asymmetric solid inner core.

D. Anderson
December 12, 2020 1:06 pm

I just learned that traps is Swedish for steps, because they go up like steps and an early scientist who studied them was Swedish.

John Tillman
Reply to  D. Anderson
December 12, 2020 3:32 pm

Stairs. Swedish “trappa” means “stairs” or “staircase”. It came from Swedish miners, and was picked up by 18th century Swedich minerologists.

D. Anderson
Reply to  John Tillman
December 12, 2020 4:25 pm

In American English we use stairs and steps interchangeably.

He fell down the steps and broke his leg.

John Tillman
Reply to  D. Anderson
December 12, 2020 4:53 pm

In Swedish, no. Trappa means stairway or staircase.

Phil Salmon
Reply to  D. Anderson
December 13, 2020 12:13 am

“Stairs” in:
Dutch: trap
German: treppe
Norwegian: trap
Danish: trapp
Swedish: trappa

So it’s similar in all the Nordic north European languages with a Germanic origin. Which of course does not include Finnish where stairs = portaat

Reply to  Phil Salmon
December 13, 2020 5:01 am

Indo-European “Dreb”.
How did “to step” became trap, which one steps into?

Doug Huffman
Reply to  D. Anderson
December 13, 2020 4:15 am

That’s pretty sloppy language on the slippery slope to Eubonics. “Ugga bugga bing bong.”

But then William Shakespeare is a long dead old white guy.

December 12, 2020 1:13 pm

Seems like the democrats try to do that every 4 years here…

December 12, 2020 1:32 pm

Planned Population? Humans operate in compressed cycles. That said, the last and next faunal selection will not be observed, but inferred.

Gary Pearse
December 12, 2020 1:34 pm

I’m afraid that a biologist (practitioner of the first science to have been deeply politically corrupted) doesn’t get an easy pass from me, particularly, when operating in the paleontological and geological field. Biologists have been taught that ecology is like a painting, unchanging unless humans did something bad.

Somewhere in the narrative the natural event points to the extreme disaster that happens with elevated CO2, acid rain, ozone depletion, ocean acidification, pollution,’tilling of the soil’ … the identical outcome of the activities of evil humankind.

Reply to  Gary Pearse
December 12, 2020 5:20 pm

“Biologists have been taught that ecology is like a painting, unchanging unless humans did something bad.”

When they should understand their hubris just like the climate changers need to-
What’s the latest figures on Spanish Flu mortality by the way? Have they discovered a vaccine for it yet?

John Tillman
Reply to  observa
December 12, 2020 6:20 pm
December 12, 2020 5:30 pm

Sounds like Brahma starts to nod off every 27 million years & catches himself before fully falling asleep. That’s understandable while staying awake, what with creation having four ages cycling through 1,000 times before the allowed annihilation knocks him out for an equal duration.

December 12, 2020 7:00 pm

most of the events in the article seems to line up pretty well except the Manicougan crater which is is way off the cycle.
Manicougan at 215 Ma is almost as far from the cycle as it is possible to get.

Paul of Alexandria
Reply to  Jon
December 13, 2020 10:51 am

There are other triggers for Oort Cloud disturbances, including blind chance.

Doug Huffman
December 13, 2020 4:11 am

The paper cites my friend, neighbor and mentor David M. Raup RIP, and coauthor Seposki.

December 13, 2020 6:15 am

Sharks have a secret they are not telling us.
Not sure waterboarding will work though.

December 13, 2020 8:18 am

For interest see articles by Melott on extinction cycles :

The galactic bow shock, now observed for some other galaxies, with increased cosmic ray flux, as well as nearby supernova sources are all considered. The spiral arms are volumes of increased star activity .

Tom Abbott
December 13, 2020 6:02 pm

From the article: “The researchers were surprised to find another possible explanation beyond asteroids for mass extinctions: flood-basalt eruptions, or giant volcanic eruptions that cover vast areas with lava. All eight of the coinciding mass die-offs on land and in the oceans matched times of flood-basalt eruptions. These eruptions also would have created severe conditions for life, including brief periods of intense cold, acid rain, and ozone destruction and increased radiation; longer term, eruptions could lead to lethal greenhouse heating and more acid and less oxygen in the ocean.

“The global mass extinctions were apparently caused by the largest cataclysmic impacts and massive volcanism, perhaps sometimes working in concert,” added Rampino.”

The asteriod impact itself may be the cause of the flood-basalt eruptions.

“We present the results of shock physics and seismological computational simulations that show how energy from a large impact can be coupled to the interior of the Earth. . .

We propose that if large impacts on the Earth leave geological evidence anywhere other than the impact site itself, it will be at the antipode. We suggest that the most likely result of the focusing for a sufficiently large impact, consistent with features observed in the geological record, would be a flood basalt eruption at the antipode followed by hotspot volcanism.”

end excerpts

December 13, 2020 11:22 pm

So the point in all this is that there is no point in trying to save anything. It will all get destroyed one way or the other. Better get the hell out of here as soon as we can. Spread our seeds in the universe for better race survival.

December 14, 2020 8:25 am

Dr. Walter Alvarez wrote a book called ‘Nemesis’.

He found that every 29 million years, the same happened; though whether 27 – 29 My does not matter. What his theory was that Nemesis is a star that performed a near pass of our solar system and performed exactly the same result. He was the one that inspired the Time cover of the Yucatan asteroid (comet) hit that ended the dinosaur era.

I am a little surprised to see this repeat. Motorola named their satellite phone Iridium as there was always a fine layer of higher concentrations of Iridium in the soil.

The book is a great read.

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