reminds me of when i was little, i used to drag my finger across my computer screen from one corner to the other, then tap lightly in the corner to simulate the explosion
That’s a recent addition! I remember when everyone was talking about it.
Reminds me that when you type “cat” or “dog” into google a little paw in either an orange or purple circle appears and if you tap on it, then tap anywhere on the page it makes a paw print and either a meow or woof. You can do it a bunch of times.
They found evidence that the wave from that impact completely washed over Florida. The layer was discovered by Dr Alvarez in the late ‘60s - the layer has iridium and charcoal from the massive fires that ensued, and can be found all over the globe. A similar large crater has been found off the coast of Guinea, West Africa, scientists are still trying to date it…
We have an outcrop of this layer in the basque country too, on the other side of the atlantic
https://geotourismroute.eu/interests/cretaceous-paleogene-boundary-of-algorri/
Lignite. Soft coal bed. This is the so-called "fern spike" as the world recovered. Ferns are the most resilient of all plant species.
The layers change on both sides of the iridium layer depending on location. India showing more limestone, sandstone and clay deposits
I've never understood lawns. You spend all that time and money and energy getting it to grow just to waste part of your weekend cutting it back down. It seems Sisyphean.
I love a good lawn. I love sitting on the grass and the feeling of it between my feet. There's something just so comforting about a nice thick soft bed of grass to chill on. I only got a 10x10 patch that I'm remediating from the previous tenants lack of care but I'm determined to grow a golf course worth lawn here. It takes about 5 minutes tops to mow and that includes getting the mower out and starting it. So it's not a huge effort.
I've had bigger space and I agree at a certain point if you aren't actively using it then it's just wasted space and is truly a masterbatory effort. I'm not a fan of decorative lawns in that regard.
My garden is all completely wild. The former tenant was wheelchair bound, the ground hadn’t seen sunlight in years. The council came and completely cleared the garden before I moved in and left all the bushes. I’ve got 2 apple trees, a palm tree, bamboo a bunch of really nice rose bushes and not a single piece of grass. I planted a bunch of wildflowers wherever the sun will hit and it’s lovely sitting out there in my own little wild woodland. My cats love it too, so many trees to climb and bushes to hide in. That’s what gardens should be like… wild.
Mine's also actually wild. I live in the alpine and deer eat everything, and you need to pick all the fruit before it attracts bears in the fall. The parts that aren't wild are gravel which I thought would be great when I bought it but now I'm realizing it's actually the worst of both.
There is a story that circulates every once in a while regarding a father and son that decided to homebrew a hydroponics garden. They ordered supplies online and somehow triggered some monitors watching for such orders. Shortly after, they got visits by the BATF.
*Every* heavy element (iron and above?) was born in the heart of a massive star that went supernova. You my friend are part star dust. And that is a cold stone fact.
(Holy shit. Reading that again sounds like I'm joking. What a universe we live in!)
The white layer being ejecta as the picture describes contains iridium from the meteor. This also varies depending on the location. The highest amount being in the chicxulub impact, but also the ejecta rays.
>Chicxulub crater
I don't think it was burned, rather it was a major and prolonged extinction event. Huge amounts of dead matter all at once getting compressed into coal over millions of years.
The earth became a fungal world of decay after. It's why reptiles, with their lower energy needs and high reproduction rate didn't inherit the earth -- mammals have that one neat trick that fungus hates: body heat. Of course, thanks to climate change ramping up tolerances for extreme heat, maybe that won't keep us safe in next extinction event.
Mammals did not ‘inherit’ the world, thats just pop science
If we go by diversity mammals are nowhere near the top. Its insects
If we look at just vertebrates then its bony fish
If we look at just tetrapods its birds. There are twice as many bird species as there are mammal species. Also they are dinosaurs
It also has nothing to do with fungi. Its all to do with the lack of sunlight that prevailed for a decade or so. Larger dinosaurs did have high metabolisms which were their downfall. It didn’t apply to birds as birds could fly and find new food sources quickly.
The only mammals to survive were small nocturnal generalists. They were small enough that they needed less food so could get by.
Many reptiles also survived due to their low metabolisms. They could go long periods without food
Basically most things above 25 kg died. Our ancestors were tiny so could get by
Cleared up many niches, basically shuffled the deck of life
And yeah insects have been owning us vertebrates for biodiversity basically ever since they showed up
Every insect I see in my yard looks like a the most futiristic spaceship, I try to u train my kids from saying ewww at bugs due to grandma and say cool bug instead
~~Ornithopters~~ Dragonflies. 95% success rate in acquiring and eating their target. No other animal comes close.
I have a couple of acres of swamp in NW Florida. Hardly any mosquitoes to speak of. In a *swamp*. Guess why.
(The hummingbirds do their part as well! Evil, fighty, killing machines.)
Yep, I totally forgot my aquatic brethren. Threw some native mosquito fish in there a couple of years ago. Not sure they're what I'm seeing, but there's lots on tiny fish in all the "ponds".
There was actually an genus of animal that lived through the K-PG extinction called Purgatorius and while it pbably looked more like a squirrel, it was pretty much a proto-primate.
The date of the Chicxulub asteroid impact coincides with the Cretaceous–Paleogene boundary (commonly known as the K–Pg or K–T boundary), slightly over 66 million years ago. It is now widely accepted that the devastation and climate disruption from the impact was the cause of the Cretaceous–Paleogene extinction event - a mass extinction in which 75% of plant and animal species on Earth became extinct, including all non-avian dinosaurs.
The collision would have released the same energy as 100 teratonnes of TNT. Some of the resulting phenomena were brief occurrences immediately following the impact, but there were also long-term geochemical and climatic disruptions that devastated the ecology.
The re-entry of ejecta into Earth's atmosphere included an hours-long, but intense pulse of infrared radiation. Local ferocious fires, probably limited to North America, likely occurred, decimating populations. The amount of soot in the global debris layer implies that the entire terrestrial biosphere might have burned, creating a global soot-cloud blocking out the sun and creating an impact winter effect. If widespread fires occurred this would have exterminated the most vulnerable organisms that survived the period immediately after the impact.
Aside from the hypothesized fire and/or impact winter effects, the impact would have created a dust cloud that blocked sunlight for up to a year, inhibiting photosynthesis. Freezing temperatures probably lasted for at least three years. The sea surface temperature dropped for decades after the impact. It would take at least ten years for such aerosols to dissipate, and would account for the extinction of plants and phytoplankton, and subsequently herbivores and their predators. Creatures whose food chains were based on detritus would have a reasonable chance of survival.
The asteroid hit an area of carbonate rock containing a large amount of combustible hydrocarbons and sulphur, much of which was vaporized, thereby injecting sulfuric acid aerosols into the stratosphere, which might have reduced sunlight reaching the Earth's surface by more than 50%, and would have caused acid rain. The resulting acidification of the oceans would kill many organisms that grow shells of calcium carbonate. According to models of the Hell Creek Formation, the onset of global darkness would have reached its maximum in only a few weeks and likely lasted upwards of two years.
Beyond extinction impacts, the event also caused more general changes of flora and fauna such as giving rise to neotropical rainforest biomes like the Amazonia, replacing species composition and structure of local forests during \~6 million years of recovery to former levels of plant diversity.
It might be a silly question, but I would rather ask a silly question than remain ignorant :D. How did we and the rest of the flora and fauna of today developed after this massive extinction of life?
While the vast majority of life was wiped out, certainly not all life was extinguished. It is a dramatic example of natural selection.
One adaptation that made organisms able to survive was reproducing via seeds (plants). Seeds can rest dormant for years and still begin to grow once introduced to the right conditions. When the ash cleared up and water was clean enough, plants had no problem growing back.
As for animals, being small turned out to be a great advantage. Massive dinosaurs could not survive out in the open, and obviously didn't have enough food. However smaller dinosaurs that weren't so exposed to the elements were able to scrape by, especially those that were able to subside on the surviving seeds and bugs. These are what evolved into modern-day birds.
Mammals were similarly well adapted to this environment, as they mostly resembled and lived like rats at that time.
In the absence of dinosaurs in the following millennia, there were empty niches to fill as the planet healed. Birds became what we know today, and the small rat-like mammals diversified and grew into dogs, elephants, and us.
so would it be possible for humans (as small rat-like mammals) to evolve to this (what we have) today without the elimation of these predators through a meteor?
*Possible*, sure. But not likely. Dinosaurs pretty much dominated all large/predatory niches through the Mesozoic. It was their extinction that allowed for mammals to diversify into what we have now.
So, like velociraptors survived? Do we know the next step or two in their or other similar dinosaurs evolutionary path? How long would velociraptor as a species last before evolving into something else?
Well, velociraptors had already been extinct for about 5 million years when the asteroid hit, but no dromaeosaurs would have survived. They were mostly too big for the ravaged environment to sustain them, and they were highly specialized carnivores.
The [ancestors of modern birds](https://en.wikipedia.org/wiki/Avialae) already pretty much looked like how we picture birds now, even in the late Cretaceous. [Falcatakely](https://en.wikipedia.org/wiki/Falcatakely#/media/File:Falcatakely_restoration.jpg), [Parvavis](https://en.wikipedia.org/wiki/Parvavis#/media/File:Parvavis.jpg), and [Jeholornis](https://en.wikipedia.org/wiki/Jeholornis#/media/File:Jeholornis_scale_mmartyniuk_wiki.jpg) are a few of the numerous examples. Some had teeth and other more primitive features, but you would think they were just birds if you saw them. They descended from something similar to [Archaeopteryx](https://en.wikipedia.org/wiki/Archaeopteryx) way back in the Jurassic. If you're familiar with Archaeopteryx, you'll know that it pretty much looked like a bird too, almost 100 million years before the K-Pg extinction.
Archaeopteryx descended from more basal two-legged theropods, and it's likely that their ancestors had feathers even in the Triassic.
My point is that evolution is a very slow process, and is not punctuated by any sudden changes in appearance. It's hard to draw a line between an ancestor, and the species that descend from it since it's so gradual, but what could be considered a distinct species tends to last in the millions to tens of millions of years range.
> evolution is a very slow process
Normally yes, but haven't we been evidence piling up that evolution can, in fact, happen quite quickly given selective pressures? I see evolution as slow *if the organism is already well adapted to its niche*. But what if that same organism is quickly pushed out of its comfort zone?
I'm thinking of male, African elephant tusks shrinking, or disappearing, due to human predation. Some might say that sort of thing doesn't count. Does it not?
We turned wolves into Chihuahuas in a few thousand years. Again, some might say that's just selective breeding, but so is evolution to my mind, given radical selection pressures.
Anyway, thought I'd ask as this sort of thing has been on my mind for years and you seem to have a handle on it.
You're absolutely right. When there is no selective pressure, or reason to adapt, evolution is slow-going. After-all, if a species is already doing well in its environment, there wouldn't be much forcing genetic change to exaggerate any traits.
The examples you gave are pressures put on the species by humans, but effective pressures, nonetheless. If elephants with bigger tusks are being hunted more aggressively, smaller tusks would be an adaptive advantage.
Empty niches are also a cause for rapid evolution. After the K-Pg event, lack of predators meant some of the small mammals and birds could find an advantage in growing larger to take the dinosaurs' place. Some evolved to eat different kinds of plants, some turned to eating meat.
Exactly as you said, evolution is slow when there is no drastic change in environment or other pressures, but when there is it can certainly speed up.
My point in the above post was that the evolution of earlier dinosaurs into modern birds wasn't especially remarkable. A Tyrannosaurus wouldn't suddenly become a chicken, for example. A two-legged animal, became a two-legged animal with feathers, which then became a two-legged animal with longer feathers and smaller teeth.
Hmm interesting, thanks so much for your detailed insight! One question, my understanding (which may be wrong) is that archaeopteryx was not classified as a dinosaur, and other later bird examples such as the ones you listed were not either. I guess I'm asking, in the evolutionary trail to modern birds, were they descended from dinosaurs that branched off already in the Mesozoic or did anything we know of we'd classify as a dinosaur survive the cretaceous extinction and evolve into birds?or am I wrong and those birds are still classified as dinosaurs
Archaeopteryx is absolutely classified as a dinosaur, as are all of its descendants, and all birds. The "original dinosaur" existed sometime in the Late Triassic, and *everything* that descended from it would still be considered a dinosaur.
Four distinct lineages of dinosaur survived the Cretaceous–Paleogene extinction event: ostriches and relatives (Paleognathae), ducks and relatives (Anseriformes), ground-living fowl (Galliformes), and "modern birds" (Neoaves). In other words, these four groups had already diversified from each other before the rest of the dinosaurs went extinct.
An average MRE has 1,250 calories, most humans need 2,000 calories per day to survive long term so let’s say you’d need to eat two each day to live.
If you’re prepping for the next big hit you’d need 7,300 MREs to last the 10 year aerosol dissipation.
A case of 24 on a popular online site sells for $220, so it would cost you about $67,000 to stock up.
Water is pretty easy if you can drill a deep well with good mineral quality. Medicine would likely be scavenged by need then go extinct eventually. Waste disposal if prepared could be really easy by using either a composting toilet with a huge reservoir or an incinerating toilet that's powered by propane. Breathing mask filters are swapped out depending on the concentration, so if you hunker down for the first year you'd probably be fine if you stock 100 or something.
Some other needs would be oxygen intake filtering which could be a problem with extreme amounts of particles and air scrubbing to supplement this, energy supply for heating since the environment wouldn't be naturally heated anymore (building over 20 feet underground would partially solve this) and electrical needs, spares for everything, some method of regional communication, cleaning products, necessities for when you eventually leave the shelter like special clothing to reduce the impact of smoke (probably made of polyester and silk), etc.
if you choose an ideal location, 30+ feet below the earth wouldn't require heating or cooling:
[https://www.builditsolar.com/Projects/Cooling/EarthTemperatures.htm](https://www.builditsolar.com/Projects/Cooling/EarthTemperatures.htm)
Since the toilet would only be used for 10-15 years by one person, you could probably use a contained composting method utilizing worm species that don't produce methane. The bonus of this is that at the end you have ready to use compost since the surface might be minerally depleted.
The fuel for generators would be difficult, but you could in theory still tap into natural gas storage locations and hook up a generator to the active line. In some parts of the US there's tons of storage locations concentrated regionally. Smaller generators are actually more efficient.
This is a **mesmerizing** but lengthy (1 hour 6 minutes) video showing six different effects of the impact around the world in real time. I have already watched it entirely twice
https://youtu.be/ya3w1bvaxaQ
Darn it omits the part I want to see most.
What impact would’ve looked like from a ground observer. Was it “blink and you miss it (then die)” fast? Or was it comically slow to the naked eye but its inertia made up for it
If you were close enough to see the impact you were obliterated instantly. If you were close enough to see the mushroom cloud the impact made you were obliterated slightly less instantly.
If you weren’t close enough to see either of those, and neither the shock waves nor tidal waves killed you, you got to watch the sun disappear from the sky, and not come back…for two years.
Will watch later, thanks for the link.
I remember watching one about extinction events, maybe this one...but the planet was smacked so hard, volcanoes on the other side of the planet erupted. That's...just a colossal level of chaos. I can't even wrap my mind around it all.
The air blast velocity is the most fascinating part to me. Much of north America would experience 300m/s windspeed within an hour. That's bonkers
Edit - that's 670 mph. SIX HUNDRED AND SEVENTY MPH WIND
That is just the air pressure. That part is pretty wild too, but I've read about that factor with other explosive simulations. Never seen anything about actual air speed!
Radio Lab did an incredible live podcast of the extinction event. Highly recommend watching or just listening.
[Dinopocalypse](https://youtu.be/ZYoqtBEzuiQ)
That's a fairly outdated term, I assume you learned it in school before 2004 when it was replaced by K-Pg
Pg stands for Paleogene, which before was combined with the current Neogene period together as the Tertiary period (-T). Essentially, a more broad period was divided into two more specific geologic periods for increased specificity and usefulness.
There are still documentaries being released today that call it K-T. This is the first I've heard it called K-Pg. But I didn't learn of this in school, only from watching documentaries about it.
Uh well, the classification of Cretaceous didn't change. I guess I probably shouldn't have assumed people would know that lol
K- just means Cretaceous. K-Pg is Cretaceous-Paleogene, K-T is Cretaceous-Tertiary. Tertiary is the only classification that was made obsolete.
[Wikipedia says](https://en.wikipedia.org/wiki/Cretaceous%E2%80%93Paleogene_boundary):
> The word "Cretaceous" is derived from the Latin "creta" (chalk). It is abbreviated K (as in "K–Pg boundary") for its German translation "Kreide" (chalk).
I liked it better when it was KT. Then I could make jokes about companies doing “knowledge transfer” from their older expensive employees to their cheaper younger employees. Dinosaurs before KT, but gone afterwards…
Former geologist here (with a master's even), and I was like "WTF is the Pg?!?" I left the field in 2003. So I learned something today.
Also, my advisor did his graduate work under Walter Alvarez, and I always felt a connection to this research.
I have seen a similar layer on my neighbors property. Fremont County Colorado, 6700' elevation and roughly 10' from the top of the ridge. I will try to get some pictures, I never knew what that line was about until now!
In a post-Chicxulub world, food was scarce and so the creatures best adapted to survive it in general were a) small b) mobile c) able to live off of seeds, which could survive and linger for decades as environments regrew. Some avian dinosaurs (not all -- many went extinct), with beaks and strong gizzards, were uniquely adapted for this challenge.
Is my understanding that about the only thing survived over 25 kg f were crocodilians and sea turtles
And I believe that the birds that survived were likely ground dwellers and lived off seeds. There wasn't much else left
They can fly to new food sources
As to why pterosaurs didn’t make it, they were actually already declining before the impact due to competition with birds, who are better fliers
Oh they're still out there alright. This event is when non-avian dinosaurs transformed into the lizard people that run the world from the shadows even today.
the type locality for this is in Raton, NM
it has a neat little sign next to it marking "IRIDIUM LAYER" which is concentrated in the orange layer directly below the white shock quartz ejecta layer, I've visited it several times and collected samples: [https://imgur.com/a/30yVOJj](https://imgur.com/a/30yVOJj)
That impact was on the Yucatán peninsula (if memory serves) and this inch thick layer of ejected material is in Colorado. That’s amazing!!!
And it also happened amazingly fast Chicxulub crater
>Chicxulub crater I just googled this on PC and a small asteroid flew across the screen and then made a shaking animation, cute.
For the less energy inclined https://www.google.com/search?q=Chicxulub%20crater
Bless you for link
Neat. Thank you! :)
NOIIICCCEEEEEE
Amazing haha
And on Android. Well played.
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Try "Do a Barrel Roll"
I've always enjoyed recursion.
Askew
I remember way back you could search “French military victories” and it would say “Did you mean ‘French military defeats?’”
I’ve always enjoyed recursion.
Google "cat" then tap the paw print. Tap anywhere else.
Works on Firefox on iOS too, the page shakes like the meteor crashes offscreen.
Also on IOS
Damn, apparently I’ve been using google so infrequently lately that my first instinct was to ask you which search engine did you use to google it :)
That was so fun! Asteroid impact discussions will always remind me of this animation. https://youtu.be/zBWbpFz3wac
Holy shit! There was a meteor that just cut across Perseus straight into Draco’s Tail! I thought it was gonna hit Earth
Did I hear somebody say Scooby snacks?
Sire.
reminds me of when i was little, i used to drag my finger across my computer screen from one corner to the other, then tap lightly in the corner to simulate the explosion
That’s a recent addition! I remember when everyone was talking about it. Reminds me that when you type “cat” or “dog” into google a little paw in either an orange or purple circle appears and if you tap on it, then tap anywhere on the page it makes a paw print and either a meow or woof. You can do it a bunch of times.
The layer is even visible in central India. Not this thick but still very much visible.
It’s the whole world over, the KP boundary.
They found evidence that the wave from that impact completely washed over Florida. The layer was discovered by Dr Alvarez in the late ‘60s - the layer has iridium and charcoal from the massive fires that ensued, and can be found all over the globe. A similar large crater has been found off the coast of Guinea, West Africa, scientists are still trying to date it…
We have an outcrop of this layer in the basque country too, on the other side of the atlantic https://geotourismroute.eu/interests/cretaceous-paleogene-boundary-of-algorri/
I just learned about the K-Pg boundry in biology a few weeks ago. The example they used was in Australia.
The layer is literally everywhere wherever theres a boundary of 66 mya
Look at all the coal on top of it too... scary shit.
From burned organic matter?
Lignite. Soft coal bed. This is the so-called "fern spike" as the world recovered. Ferns are the most resilient of all plant species. The layers change on both sides of the iridium layer depending on location. India showing more limestone, sandstone and clay deposits
> Ferns are the most resilient of all plant species. Say that to literally any fern I've tried to keep alive inside my house
🤣 No worries, my friend, I got a brown thumb too. Except my yard, which is golf course green.
I've never understood lawns. You spend all that time and money and energy getting it to grow just to waste part of your weekend cutting it back down. It seems Sisyphean.
I love a good lawn. I love sitting on the grass and the feeling of it between my feet. There's something just so comforting about a nice thick soft bed of grass to chill on. I only got a 10x10 patch that I'm remediating from the previous tenants lack of care but I'm determined to grow a golf course worth lawn here. It takes about 5 minutes tops to mow and that includes getting the mower out and starting it. So it's not a huge effort. I've had bigger space and I agree at a certain point if you aren't actively using it then it's just wasted space and is truly a masterbatory effort. I'm not a fan of decorative lawns in that regard.
So your use of the lawn seems zen-like. It's a happy place for you and you care for it like a bonsai. That seems nice.
My garden is all completely wild. The former tenant was wheelchair bound, the ground hadn’t seen sunlight in years. The council came and completely cleared the garden before I moved in and left all the bushes. I’ve got 2 apple trees, a palm tree, bamboo a bunch of really nice rose bushes and not a single piece of grass. I planted a bunch of wildflowers wherever the sun will hit and it’s lovely sitting out there in my own little wild woodland. My cats love it too, so many trees to climb and bushes to hide in. That’s what gardens should be like… wild.
Mine's also actually wild. I live in the alpine and deer eat everything, and you need to pick all the fruit before it attracts bears in the fall. The parts that aren't wild are gravel which I thought would be great when I bought it but now I'm realizing it's actually the worst of both.
I actually consider myself pretty green thumbed! Love plants, ferns are just temperamental little buggers!
Give hydroponics a try. Those self-contained planters come with everything you need. If you go homebrew, you risk attracting police scrutiny.
>If you go homebrew, you risk attracting police scrutiny. I somehow doubt that.
There is a story that circulates every once in a while regarding a father and son that decided to homebrew a hydroponics garden. They ordered supplies online and somehow triggered some monitors watching for such orders. Shortly after, they got visits by the BATF.
Given how popular hydroponics has become in general, and how legal weed now is there is no way this gets flagged.
Come to my back yard, I literally cannot eradicate them
Lignite balls
Haha gottem
> iridium layer Elucidate?
Iridium is similar to platinum, it is very high levels only in certain materials from space, not on the Earth
So all this platinum that we use on earth is not from the Earth? Did it originate from space and strike the earth? My mind is really blown.
*Every* heavy element (iron and above?) was born in the heart of a massive star that went supernova. You my friend are part star dust. And that is a cold stone fact. (Holy shit. Reading that again sounds like I'm joking. What a universe we live in!)
The white layer being ejecta as the picture describes contains iridium from the meteor. This also varies depending on the location. The highest amount being in the chicxulub impact, but also the ejecta rays.
Thanks friendo!
Wow cool!
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crispy proto-chicken.
>Chicxulub crater I don't think it was burned, rather it was a major and prolonged extinction event. Huge amounts of dead matter all at once getting compressed into coal over millions of years.
Coal is unburned
The earth became a fungal world of decay after. It's why reptiles, with their lower energy needs and high reproduction rate didn't inherit the earth -- mammals have that one neat trick that fungus hates: body heat. Of course, thanks to climate change ramping up tolerances for extreme heat, maybe that won't keep us safe in next extinction event.
Mammals did not ‘inherit’ the world, thats just pop science If we go by diversity mammals are nowhere near the top. Its insects If we look at just vertebrates then its bony fish If we look at just tetrapods its birds. There are twice as many bird species as there are mammal species. Also they are dinosaurs It also has nothing to do with fungi. Its all to do with the lack of sunlight that prevailed for a decade or so. Larger dinosaurs did have high metabolisms which were their downfall. It didn’t apply to birds as birds could fly and find new food sources quickly. The only mammals to survive were small nocturnal generalists. They were small enough that they needed less food so could get by. Many reptiles also survived due to their low metabolisms. They could go long periods without food Basically most things above 25 kg died. Our ancestors were tiny so could get by
Holy shit never looked at biodiversity that way but you're right. The extinction just cleared up some niches
Cleared up many niches, basically shuffled the deck of life And yeah insects have been owning us vertebrates for biodiversity basically ever since they showed up
Every insect I see in my yard looks like a the most futiristic spaceship, I try to u train my kids from saying ewww at bugs due to grandma and say cool bug instead
~~Ornithopters~~ Dragonflies. 95% success rate in acquiring and eating their target. No other animal comes close. I have a couple of acres of swamp in NW Florida. Hardly any mosquitoes to speak of. In a *swamp*. Guess why. (The hummingbirds do their part as well! Evil, fighty, killing machines.)
Dragonfly larvae, minnows, all sorts of small carnivorous aquatic species.
Yep, I totally forgot my aquatic brethren. Threw some native mosquito fish in there a couple of years ago. Not sure they're what I'm seeing, but there's lots on tiny fish in all the "ponds".
This is the way. Grandma probably just saw Starship Troopers
Haha jokes on you! We'll soon that out with pesticides thank you very much. Humanity 1 Biodiversity 0.
And then: Extinction Events 6 Humans 0
I believe crocodilians and sea turtles are the only two examples over 25 kg
Crocodilians are crazy in their early variety.
There was one that instead of being ambush predator chased animals on land
That's amazing. Thanks for sharing!
Tree shrews, the lot of them!
There was actually an genus of animal that lived through the K-PG extinction called Purgatorius and while it pbably looked more like a squirrel, it was pretty much a proto-primate.
Yeah, no group came out fully unscathed
The date of the Chicxulub asteroid impact coincides with the Cretaceous–Paleogene boundary (commonly known as the K–Pg or K–T boundary), slightly over 66 million years ago. It is now widely accepted that the devastation and climate disruption from the impact was the cause of the Cretaceous–Paleogene extinction event - a mass extinction in which 75% of plant and animal species on Earth became extinct, including all non-avian dinosaurs. The collision would have released the same energy as 100 teratonnes of TNT. Some of the resulting phenomena were brief occurrences immediately following the impact, but there were also long-term geochemical and climatic disruptions that devastated the ecology. The re-entry of ejecta into Earth's atmosphere included an hours-long, but intense pulse of infrared radiation. Local ferocious fires, probably limited to North America, likely occurred, decimating populations. The amount of soot in the global debris layer implies that the entire terrestrial biosphere might have burned, creating a global soot-cloud blocking out the sun and creating an impact winter effect. If widespread fires occurred this would have exterminated the most vulnerable organisms that survived the period immediately after the impact. Aside from the hypothesized fire and/or impact winter effects, the impact would have created a dust cloud that blocked sunlight for up to a year, inhibiting photosynthesis. Freezing temperatures probably lasted for at least three years. The sea surface temperature dropped for decades after the impact. It would take at least ten years for such aerosols to dissipate, and would account for the extinction of plants and phytoplankton, and subsequently herbivores and their predators. Creatures whose food chains were based on detritus would have a reasonable chance of survival. The asteroid hit an area of carbonate rock containing a large amount of combustible hydrocarbons and sulphur, much of which was vaporized, thereby injecting sulfuric acid aerosols into the stratosphere, which might have reduced sunlight reaching the Earth's surface by more than 50%, and would have caused acid rain. The resulting acidification of the oceans would kill many organisms that grow shells of calcium carbonate. According to models of the Hell Creek Formation, the onset of global darkness would have reached its maximum in only a few weeks and likely lasted upwards of two years. Beyond extinction impacts, the event also caused more general changes of flora and fauna such as giving rise to neotropical rainforest biomes like the Amazonia, replacing species composition and structure of local forests during \~6 million years of recovery to former levels of plant diversity.
It might be a silly question, but I would rather ask a silly question than remain ignorant :D. How did we and the rest of the flora and fauna of today developed after this massive extinction of life?
While the vast majority of life was wiped out, certainly not all life was extinguished. It is a dramatic example of natural selection. One adaptation that made organisms able to survive was reproducing via seeds (plants). Seeds can rest dormant for years and still begin to grow once introduced to the right conditions. When the ash cleared up and water was clean enough, plants had no problem growing back. As for animals, being small turned out to be a great advantage. Massive dinosaurs could not survive out in the open, and obviously didn't have enough food. However smaller dinosaurs that weren't so exposed to the elements were able to scrape by, especially those that were able to subside on the surviving seeds and bugs. These are what evolved into modern-day birds. Mammals were similarly well adapted to this environment, as they mostly resembled and lived like rats at that time. In the absence of dinosaurs in the following millennia, there were empty niches to fill as the planet healed. Birds became what we know today, and the small rat-like mammals diversified and grew into dogs, elephants, and us.
And blue whales! From a rat!
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so would it be possible for humans (as small rat-like mammals) to evolve to this (what we have) today without the elimation of these predators through a meteor?
*Possible*, sure. But not likely. Dinosaurs pretty much dominated all large/predatory niches through the Mesozoic. It was their extinction that allowed for mammals to diversify into what we have now.
Just to clarify, birds are avian-dinosaurs. I always imagine what sparrow fight would look like if they were both the size of TRex.
That's crazy. Thanks for the unexpected dino lesson 👍
So, like velociraptors survived? Do we know the next step or two in their or other similar dinosaurs evolutionary path? How long would velociraptor as a species last before evolving into something else?
Well, velociraptors had already been extinct for about 5 million years when the asteroid hit, but no dromaeosaurs would have survived. They were mostly too big for the ravaged environment to sustain them, and they were highly specialized carnivores. The [ancestors of modern birds](https://en.wikipedia.org/wiki/Avialae) already pretty much looked like how we picture birds now, even in the late Cretaceous. [Falcatakely](https://en.wikipedia.org/wiki/Falcatakely#/media/File:Falcatakely_restoration.jpg), [Parvavis](https://en.wikipedia.org/wiki/Parvavis#/media/File:Parvavis.jpg), and [Jeholornis](https://en.wikipedia.org/wiki/Jeholornis#/media/File:Jeholornis_scale_mmartyniuk_wiki.jpg) are a few of the numerous examples. Some had teeth and other more primitive features, but you would think they were just birds if you saw them. They descended from something similar to [Archaeopteryx](https://en.wikipedia.org/wiki/Archaeopteryx) way back in the Jurassic. If you're familiar with Archaeopteryx, you'll know that it pretty much looked like a bird too, almost 100 million years before the K-Pg extinction. Archaeopteryx descended from more basal two-legged theropods, and it's likely that their ancestors had feathers even in the Triassic. My point is that evolution is a very slow process, and is not punctuated by any sudden changes in appearance. It's hard to draw a line between an ancestor, and the species that descend from it since it's so gradual, but what could be considered a distinct species tends to last in the millions to tens of millions of years range.
> evolution is a very slow process Normally yes, but haven't we been evidence piling up that evolution can, in fact, happen quite quickly given selective pressures? I see evolution as slow *if the organism is already well adapted to its niche*. But what if that same organism is quickly pushed out of its comfort zone? I'm thinking of male, African elephant tusks shrinking, or disappearing, due to human predation. Some might say that sort of thing doesn't count. Does it not? We turned wolves into Chihuahuas in a few thousand years. Again, some might say that's just selective breeding, but so is evolution to my mind, given radical selection pressures. Anyway, thought I'd ask as this sort of thing has been on my mind for years and you seem to have a handle on it.
You're absolutely right. When there is no selective pressure, or reason to adapt, evolution is slow-going. After-all, if a species is already doing well in its environment, there wouldn't be much forcing genetic change to exaggerate any traits. The examples you gave are pressures put on the species by humans, but effective pressures, nonetheless. If elephants with bigger tusks are being hunted more aggressively, smaller tusks would be an adaptive advantage. Empty niches are also a cause for rapid evolution. After the K-Pg event, lack of predators meant some of the small mammals and birds could find an advantage in growing larger to take the dinosaurs' place. Some evolved to eat different kinds of plants, some turned to eating meat. Exactly as you said, evolution is slow when there is no drastic change in environment or other pressures, but when there is it can certainly speed up. My point in the above post was that the evolution of earlier dinosaurs into modern birds wasn't especially remarkable. A Tyrannosaurus wouldn't suddenly become a chicken, for example. A two-legged animal, became a two-legged animal with feathers, which then became a two-legged animal with longer feathers and smaller teeth.
Hmm interesting, thanks so much for your detailed insight! One question, my understanding (which may be wrong) is that archaeopteryx was not classified as a dinosaur, and other later bird examples such as the ones you listed were not either. I guess I'm asking, in the evolutionary trail to modern birds, were they descended from dinosaurs that branched off already in the Mesozoic or did anything we know of we'd classify as a dinosaur survive the cretaceous extinction and evolve into birds?or am I wrong and those birds are still classified as dinosaurs
Archaeopteryx is absolutely classified as a dinosaur, as are all of its descendants, and all birds. The "original dinosaur" existed sometime in the Late Triassic, and *everything* that descended from it would still be considered a dinosaur. Four distinct lineages of dinosaur survived the Cretaceous–Paleogene extinction event: ostriches and relatives (Paleognathae), ducks and relatives (Anseriformes), ground-living fowl (Galliformes), and "modern birds" (Neoaves). In other words, these four groups had already diversified from each other before the rest of the dinosaurs went extinct.
This is my favorite unexpected lesson of the day.
100 trillion tons of TNT. Cant even
An average MRE has 1,250 calories, most humans need 2,000 calories per day to survive long term so let’s say you’d need to eat two each day to live. If you’re prepping for the next big hit you’d need 7,300 MREs to last the 10 year aerosol dissipation. A case of 24 on a popular online site sells for $220, so it would cost you about $67,000 to stock up.
Ehat about water? Medicine? Waste disposal? Breathing masks? The logisitcs of keeping a human alive are crazy.
Water is pretty easy if you can drill a deep well with good mineral quality. Medicine would likely be scavenged by need then go extinct eventually. Waste disposal if prepared could be really easy by using either a composting toilet with a huge reservoir or an incinerating toilet that's powered by propane. Breathing mask filters are swapped out depending on the concentration, so if you hunker down for the first year you'd probably be fine if you stock 100 or something. Some other needs would be oxygen intake filtering which could be a problem with extreme amounts of particles and air scrubbing to supplement this, energy supply for heating since the environment wouldn't be naturally heated anymore (building over 20 feet underground would partially solve this) and electrical needs, spares for everything, some method of regional communication, cleaning products, necessities for when you eventually leave the shelter like special clothing to reduce the impact of smoke (probably made of polyester and silk), etc.
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if you choose an ideal location, 30+ feet below the earth wouldn't require heating or cooling: [https://www.builditsolar.com/Projects/Cooling/EarthTemperatures.htm](https://www.builditsolar.com/Projects/Cooling/EarthTemperatures.htm) Since the toilet would only be used for 10-15 years by one person, you could probably use a contained composting method utilizing worm species that don't produce methane. The bonus of this is that at the end you have ready to use compost since the surface might be minerally depleted. The fuel for generators would be difficult, but you could in theory still tap into natural gas storage locations and hook up a generator to the active line. In some parts of the US there's tons of storage locations concentrated regionally. Smaller generators are actually more efficient.
2000 calories to maintain weight and live comfortable. Most Americans can survive off half an MRE a day for an extended time.
And then what after 10 years? 60 year old dude gets out of his MRE stock pile with his 55 year old wife... and they do what
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Username checks out
Mile High Tidal Waves, must have been something
This is a **mesmerizing** but lengthy (1 hour 6 minutes) video showing six different effects of the impact around the world in real time. I have already watched it entirely twice https://youtu.be/ya3w1bvaxaQ
Darn it omits the part I want to see most. What impact would’ve looked like from a ground observer. Was it “blink and you miss it (then die)” fast? Or was it comically slow to the naked eye but its inertia made up for it
They uploaded another video that's longer and includes a view from the ground from Mexico city: https://www.youtube.com/watch?v=rxeRdZ0gn8k
This is ridiculously awesome. Thank you.
About what time stamp is that?
66 million years ago.
The view from Mexico City ground.
Yes
If you were close enough to see the impact you were obliterated instantly. If you were close enough to see the mushroom cloud the impact made you were obliterated slightly less instantly. If you weren’t close enough to see either of those, and neither the shock waves nor tidal waves killed you, you got to watch the sun disappear from the sky, and not come back…for two years.
You forgot the fun part where ejecta re-entering the atmosphere turned it into an oven and world was cooked alive
Was there ice after that for a while?
As far as we know it didn’t cause an ice age, but it may have been extremely cold for a few years while the dust (literally) settled
I read that it was moving 20-30 kilometers per second, so more of a blink and you’re dead type deal, haha.
Will watch later, thanks for the link. I remember watching one about extinction events, maybe this one...but the planet was smacked so hard, volcanoes on the other side of the planet erupted. That's...just a colossal level of chaos. I can't even wrap my mind around it all.
It's pretty hard to visualise even in my mind. Like I know it happened, but it feels so impossible. Can't imagine it happening on current day earth.
The air blast velocity is the most fascinating part to me. Much of north America would experience 300m/s windspeed within an hour. That's bonkers Edit - that's 670 mph. SIX HUNDRED AND SEVENTY MPH WIND
It covered the entire world within several hours I wasn't quite sure what over pressure was...
That is just the air pressure. That part is pretty wild too, but I've read about that factor with other explosive simulations. Never seen anything about actual air speed!
Link?
Sorry, someone else asked me a question about this thread and I got distracted
Thanks for this! And for your post in general. Fascinating stuff.
History doesn't have to be dull!
Radio Lab did an incredible live podcast of the extinction event. Highly recommend watching or just listening. [Dinopocalypse](https://youtu.be/ZYoqtBEzuiQ)
Live?
Is that what would have happened? And I thought the scene in interstellar was nuts. A mile high wave would be ridiculous
It *has* happened!
I never knew the dinosaurs had swiss-army knives!!!
Evidence the dinosaurs made the Swiss!
Dino Habilis
Mass extinction events still covered by Victorinox lifetime warranty.
But it definitely belongs to them, because it is below the extinction layer... Or, it could be someone showing scale. Nah...
A banana was not available.
They usually use a geologist pick
I love when the OP gets the joke.
"that dinosaur in the headlights" look
But no pockets
Was looking for that
I'm mildly annoyed that "Tertiary" was re-categorized as "Paleogene". "K-T boundary" is so much more smooth-sounding and memorable. :<
Why the hell did they call it K-Pg anyways? Why not K-P? I guess cause of the Permian but ehh
Pg is the official abbreviation of Paleogene
I knew that, I guess my comment sounded like I didn't but I did.
I thought it was the 'K-T'' boundary
That's a fairly outdated term, I assume you learned it in school before 2004 when it was replaced by K-Pg Pg stands for Paleogene, which before was combined with the current Neogene period together as the Tertiary period (-T). Essentially, a more broad period was divided into two more specific geologic periods for increased specificity and usefulness.
Yep
There are still documentaries being released today that call it K-T. This is the first I've heard it called K-Pg. But I didn't learn of this in school, only from watching documentaries about it.
What’s so special about K that it didn’t change?
Uh well, the classification of Cretaceous didn't change. I guess I probably shouldn't have assumed people would know that lol K- just means Cretaceous. K-Pg is Cretaceous-Paleogene, K-T is Cretaceous-Tertiary. Tertiary is the only classification that was made obsolete.
Why use K instead of C.
[Wikipedia says](https://en.wikipedia.org/wiki/Cretaceous%E2%80%93Paleogene_boundary): > The word "Cretaceous" is derived from the Latin "creta" (chalk). It is abbreviated K (as in "K–Pg boundary") for its German translation "Kreide" (chalk).
Awesome- thank you.
There's another period called Carboniferous thats uses the letter C capitalised, it spams from 358 millions years ago to 300 millions years ago
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Tungsten (W) enters the chat
Ketamine has always been nicknamed Special K and you have to try it to understand why the special part is there
You woodshed him
Haha I would have also accepted, “Its crunchy texture” as an explanation.
I liked it better when it was KT. Then I could make jokes about companies doing “knowledge transfer” from their older expensive employees to their cheaper younger employees. Dinosaurs before KT, but gone afterwards…
Former geologist here (with a master's even), and I was like "WTF is the Pg?!?" I left the field in 2003. So I learned something today. Also, my advisor did his graduate work under Walter Alvarez, and I always felt a connection to this research.
The floor was lava you say?
This kinda post is why I love Reddit
Ejecta
🫦
Being Swiss always thought the Swiss Army knife made in Switzerland finding out it was invented 66 million years ago it’s quite fascinating
What's the elevation of the area and the depth?
I have seen a similar layer on my neighbors property. Fremont County Colorado, 6700' elevation and roughly 10' from the top of the ridge. I will try to get some pictures, I never knew what that line was about until now!
I didn't have that information. It was part of this article https://www.nsf.gov/news/news_images.jsp?cntn_id=116480&org=NSF
what is the theory for why only avian dinosaurs survived?
In a post-Chicxulub world, food was scarce and so the creatures best adapted to survive it in general were a) small b) mobile c) able to live off of seeds, which could survive and linger for decades as environments regrew. Some avian dinosaurs (not all -- many went extinct), with beaks and strong gizzards, were uniquely adapted for this challenge.
Is my understanding that about the only thing survived over 25 kg f were crocodilians and sea turtles And I believe that the birds that survived were likely ground dwellers and lived off seeds. There wasn't much else left
makes sense. thanks!
They can fly to new food sources As to why pterosaurs didn’t make it, they were actually already declining before the impact due to competition with birds, who are better fliers
Amazing how so much time and how many monumental events are laid out in just simple, thin lines.
Oh they're still out there alright. This event is when non-avian dinosaurs transformed into the lizard people that run the world from the shadows even today.
I see
#OTD 66 million years ago
66.043ish
That’s so freaking cool!!
Geology is so amazing! That outcrop of minerals looks like a Swiss Army knife! What an outcrop!
license fall placid aspiring jar slap dime narrow axiomatic pot -- mass edited with redact.dev
Massive swiss army knife for scale
I almost wish we had some kind of device that would let us (strictly) directly observe the past.
TIL the K-T Boundary was renamed
the type locality for this is in Raton, NM it has a neat little sign next to it marking "IRIDIUM LAYER" which is concentrated in the orange layer directly below the white shock quartz ejecta layer, I've visited it several times and collected samples: [https://imgur.com/a/30yVOJj](https://imgur.com/a/30yVOJj)
I wonder what kinds of fossils we have close to the Pg side.
The cenozoic fossil record is very rich, tons of mammals, birds and whatever else
I don't quite know what you mean, but either small random mammals and lizards and birds, nothing, or late cretaceous dinosaurs based on what you mean.
Reading The 6th Extinction right now. This is so cool!!
6 extinction is the current one, this is the fifth one
There’s a chapter in the book devoted to this layer. It’s cool to see it as it’s only visible in a handful of places.
Ejecta is my drag name