What Killed the Dinosaurs / Series of Events Following the Asteroid Impact | GEO GIRL

[@mesozoicfishing2308]

Ayyy I am an invertebrate paleontologist specializing on the KPg boundary, this is very well done and accurate, nice work 👍

[@GEOGIRL]

Oh my gosh! Thank you so much, you have no idea how much I value this kind of comment from an actual invertebrate paleontologist! :D

[@LaManchalandsDonQuixote]

I know you specialise in KPg boundary but what's your favorite Cambrian animal???

[@phenylalanine1042]

as an invertebrate expert don't you take issue with the claim that dinosaurs were the dominant land snimals - ants, termites, nematodes, etc?

[@LaManchalandsDonQuixote]

@@phenylalanine1042 not the guy you asked the question to but holy shit yeah do i find that claim obnoxious when there's literally always more inverts than vertebrates in any given time period

[@mesozoicfishing2308]

@@phenylalanine1042 It's kind of hard to formally define dominant land animals of any time period, some may say it's based on number of estimated individuals or sheer biomass. If we go with either of these, technically plants and insects account for either one in the modern realm and not humans. I think saying that dinosaurs were the dominant lifeforms on land in the Mesozoic is a reasonable conclusion.

[@damonl9981]

It's not like I'm taking notes or anything, but your videos always feel like proper lectures. Like I'm getting an education.

[@memrjohnno]

Yep. Quality output made with passion.

[@fallinginthed33p]

Haha well I do take notes, the recent Appalachia orogeny video was chock full of good info. This channel is fast becoming like Nick Zentner of the east coast.

[@xelaxander]

I feel cheated. I expected my brain to rot a little more getting me closer to my vegetative final state but here I am leaving this video with more knowledge than I had before. Where does this all lead us /s obviously.

[@ThelBosch]

They are… except we don’t have to enroll or pay anything. 😎

[@Fetherko]

Hot for teacher

[@texcatlipocajunior144]

Where I live these days was shallow sea at the time, perhaps 20 miles from the shoreline. Really deep sand here, but 50 miles north, there is an outcrop of rock containing tsunami debris from that impact. I love your stories; they give me a sense of my place in time.

[@GEOGIRL]

Check out the part 2 here:kzbin.info/www/bejne/maHYaGd4pbyLrLs ! ;D

[@Wotan874]

Thank you, just found both videos and asked myself "Which one is the first one?" ... Could you maybe include numbers (part1/ part2) in the titles when you make such a double feature next time? btw. great video, I love your style and the option to learn cool stuff 🙂

[@Rastislav.Photography]

Hello. Please is there a way to contact you regarding Sponsorship / Business Proposal? Thank You

[@Strick.410]

I’m curious as to what it was that lead you to pursue continuing on far enough to earn an actual geo based phd. Not something I tend to see all that often. That takes some really serious commitment to reach out that far.

[@GEOGIRL]

@@Strick.410 Hi there! Actually geology and geologists are everywhere! :) Think about where are cell phones and technology comes from (mining) or where are energy comes from (oil/gas/renewables). All of these undustries are based in geology (Earth science). Other than energy and mining, geologists are also necessary in civil engineering, environmental consulting, and agriculture. But other than industry, geology can be applied to research and academia - this is the route I chose. This includes climate scientists, earthquake and other natural hazard scientists, space exploration researchers, soil scientists, ocean scientists (this was what my phd research was on), and pretty much anything else that has to do with Earth! :) For me, it was this incredible diversity of research and career options that geology offers that got me interested! :) I highly recommend it for anyone who wants to do anything related to Earth!

[@geodkyt]

My working hypothesis has been the Deccan Traps stressed the biodiversity (possibly by "moderating"☆ climate and environments across the globe in one direction, thus reducing the niche gaps between large biome regions, which would reduce biodiversity), and the impact changed things so rapidly and dramatically that the reduxed biodiversity wasn't enough for most lineages to find that small number of variants thst had compatiboe adaptations ready to go fast enough. If you have 100 distinct niches (and thus many distinct, slightly different, lineages) to choose from, you obviously have a greater chance of finding one or more that have their adaptive bingo card that is a winner for the new conditions, as opposed to if you only have 10 distinct niches. More biodiversity means a larger pool of "candidates" to "test" against the new environment(s), and so a higher likelihood of finding a "winner". . ☆ By "moderate", I don't mean in the more common climate or weatger usage of "pleasant for humans" - I simply mean reducing extremes to a mean, even if that new mean is closer to what would previously have been considered an extreme. (Such as, "The inside of my freezer moderates the temperature to 0°F +/- 5°F, as opposed to the temperature outside which ranges from about 25°F to 100°F throughout the year.")

[@zen1647]

16:32 I was confused... I thought India is on the Northern Hemisphere - but then I saw that it was on the southern hemisphere at the time! I learnt something! Bloody awesome!

[@tomschmidt381]

Always interesting learning about the KP extinction, not just about the fate of the dinos but because without it we probably would not be here. Not sure if it was or your channel or somewhere else but scientists have been able to date the time of year -June-ish of the impact, pretty impressive.

[@GEOGIRL]

Oh my gosh! I didn't know that, that is so impressive :D

[@llanitedave]

I believe that comes from data collected from the Tanis site in North Dakota. It's a virtual treasure trove of remains deposited on the day and hour of the impact. en.wikipedia.org/wiki/Tanis_(fossil_site)

[@donaldbrizzolara7720]

Rachel: Such an interesting situation to ponder. On two of our North Slope geology field parties we concentrated our effort on the upper Cretaceous section exposed along the Colville River, a sedimentary section that was very bentonitic with numerous interbedded tuff layers. A period of intense volcanism. Scattered dinosaur remains were common but near the very top of the Maastrichtian they were very abundant in what often appeared as mass mortality assemblages. Mainly edmontosaurs which was dominated by juvenile individuals. Other genera were present but not that common. The sedimentary facies appeared to be coastal plain/deltaic. Overlying the Maastrictian was a thick Paleocene section but slumping and the effects of permafrost prevented us from finding the K/T contact. To this day I’ve wondered why so many dinosaur remains were present at the top of the Cretaceous…so close to the undisclosed K/T boundary. Also, I pondered what effect the strong evidence of volcanism had on the dinosaur community. How I wish I could return there…such an extraordinary location!

[@Watchingtowatch4036]

Great video as always. Professional amateur geologist, Professional hunter and buyer of meteorites. NC native here.😊

[@NachtmahrNebenan]

Many very good arguments to support the impact. But I always struggled with the idea of a single cause. Thank you for this great lecture, Rachel - my Sunday's dose of geology! 💃

[@sambojinbojin-sam6550]

Congrats on the science communicator job. It's about time you got recognized for all your great work in this field. Legend!

[@kevingroom9892]

Enjoy learning from your videos. They are informative and well thought out. 😊

[@karthik-manickavelu]

Very Informative as usual, thank you Professor Rachel. 😀

[@toastyburger]

The KP event, like Dune, is a story so big it takes two videos to tell it! Even when I think I know a subject, you always teach me something new. I love seeing your mineral collection grow. I think I recognize one from your Appalachian video. Maybe one day you'll give us a tour. As for the Deccan Traps, the more I learn about the asteroid impact, the more convinced I am it would have caused the extinctions with or without the help of volcanism. Considering most mass extinctions are associated with volcanism and the release of carbon, it makes sense the Deccan Traps, one of the largest such events in earths history, would have done the same. But there's no strong evidence it would have wiped out non-avian dinosaurs. In fact, some paleontologists argue the dinos were well adjusted to their environment until the impact. I'll check out your video on geosociety for the answer!

[@Booger-u6m]

The Deccan Traps, Siberian Traps, and Columbia River flood basalts were deposited by rift volcanism, a type of volcanic eruption we almost don't see today. Rift volcanism occurs in Iceland, but on a much smaller scale. The eruptions that formed the Deccan Traps were truly a sight to see as rifts several miles long opened up and spewed fluid basaltic lava for years at a time. Obviously, this would release massive amounts of CO2, SO2, HFl, and other gases into the air. This would have a significant effect on the global climate and various ecosystems, but over the course of hundreds of thousands of years, so life had time to adapt. Those that couldn't went extinct and, no doubt, some did, but life as a whole carried on as usual. The Deccan Traps had already been erupting for several hundred thousand years before the Chicxulub impact event, which did the same thing the Traps did, but over just a few hours, with a few extra horrors thrown in for good measure. There's no way to adapt on such an immediate time scale, obviously, so whatever organisms didn't already have traits that enabled them to hide from the storm, so to speak, and ride it out were SOL. Goodbye cycads, ginkos, big marine reptiles and non-avian dinosaurs.

[@punditgi]

Geo Girl always enlightens us. ❤🎉😊

[@infinitumneo840]

Mass extinction, asteroid impacts, and vulcanisum are fascinating topics.The impact of a 6K wide asteroid would create massive reverberations inside the Earth. In turn, the opposite side of the Earth would experience a great amount of pressure/ energy that could cause massive volcanic activity. Thanks for your videos.

[@Booger-u6m]

If I remember right, the Indian subcontinent was not at the antipode. That was over a thousand miles east. That doesn't mean that the impact had no impact on the volcanism in what is now India. As a matter of fact, it's thought that eruptive activity increased after the impact and ended entirely several tens of thousands of years later. It's debatable how much of the post-impact volcanism was influenced by it, but, given the powerful vibrations ringing through the planet in the days afterwards, it's not inconceivable that there was some effect on the faults responsible for the Traps. 🙂

[@rwarren58]

That’s what the dinosaurs get for being complacent. After how many millions of years, they failed to come up with an anti-asteroid system. Great video❤ 🦕

[@ofoten7054]

A new study I read is that there were several astroid impacts from one and the same object that broke into several, a large impact in West Africa from the same astroid and time has been found, the next mind blowing is the earth may have had rings like saturn around for 550-620 million years ago what are your thoughts on that?

[@MrBoomer-k6v]

Great video such a fascinating topic❤

[@craiggillas6434]

Thank you for the fantastic content. 👏👏

[@robbabcock_]

What a fascinating subject! Thanks, Rachel. ☄🌋🙌

[@davevann9795]

Neil Shubin's book "Your Inner Fish" mentioned in this video's description, is also available as an excellent video mini-series of the same title.

[@florian2442]

Another certified banger ☄️💥🌊🔥☁️🌡️

[@legendre007]

oooo, important topic. By coincidence, although Godzilla turned out not to be a scientifically accurate representation of a dinosaur, some paleontologists like Kenneth Carpenter have mentioned that Godzilla inspired them to look into paleontology. And today happens to be the 70th anniversary of the release of _Godzilla_ . 🥰

[@johnp9988]

Thanks for posting/sharing with us!! Stoked to see part two!! 🍻

[@francoislalague]

Great video. Very informative and easy to follow.

[@joecanales9631]

Howdy Doc, thanks for another excellent presentation, as always well planned out and detailed. The circular pattern of sinkholes around the impact was very compelling evidence for the acid rain from impact on the carbonate region. I had looked at the timing of the impact and the volcanism of the Deccan Traps and it seemed that the volcanism might have started a bit earlier but maybe enhanced after the impact. Another question I have is how whether the impact also affected plate tectonics, maybe stirring up the mantle a bit. Thanks for your so interesting presentations. I will now look into part two. See you there.

[@neotericrecreant]

I can tell you're a good geologist, because you bring your work home with you and use it to decorate.

[@Smilo-the-Sabertooth]

Fantastic video my friend, the magnificence of the dinosaurs and the world they lived in totally fascinate me and I also really love your simple but great shirt. 🦖🦕

[@salmanzafar7188]

Dr Rachel your lectures are very informative. I am a geology graduate and learn a lot of geology knowledge from your videos.

[@ericlewis9472]

This was very well done 👍 good job!

[@GeologicalDiary]

Great video Rachel 👏!

[@robertpayne9009]

Thanks!

[@GEOGIRL]

Thanks so much! ;D

[@smashing_data4292]

13:39 The image on the right looks like what Helene did to forests in parts of NC, TN, and VA. I'm glad my property was on top of a hill with very few trees.

[@eric2max]

Excellent video! I was a geo an eon ago (only MS). Your style, backed by clear knowledge, would have been unparalleled way back when I was in school. You certainly are interesting now!

[@wantgoodvibes6166]

Thanks, another great video, :)

[@paintbrush3554]

I love your videos so much! Excitingg details!

[@pequerobles]

Love the video Rachel. Your channel is great for people like me that have a big interest in geology & paleontology 😘

[@dalemoss7877]

Years ago I read an article in Scientific American about this issue. As I recall, computer modeling showed that a huge inferno developed shortly after impact antipodally to the site on the opposite side of the globe. Do we know what region of the planet was located at that point and can you address the notion of a "second fireball" after impact, specifically whether it was a contributory factor to the extinction event?

[@billkallas1762]

How many decades ago??

[@iamsuzerain3987]

Exceedingly well-done GeoGirl...finna check out part two❤👍

[@DoktorApe]

I experienced Mt St Helens when I was a kid and I recall that one concern was about breathing the highly abrasive ash and damaging lungs, and that was in 1980 when people still smoked everywhere. Is it fair to imagine that would be one more problem after a large impact?

[@golddragonette7795]

Definitely, probably not quite the same as a pyroclastic flow but enough to kill

[@Booger-u6m]

Ashfall would only have been a minor problem. The far bigger problem for anything caught outside was the shaking ground and the reentry of impact debris in the hours afterwards. Breathing soot would have been an issue for any animals that weren't killed by the superheated atmosphere. That would have persisted for weeks, until any fires burned themselves out. Any soot particles small enough to get into the lungs and cause problems rained out of the lower atmosphere in a few months. Soot in the stratosphere took a year or more to clear out, leaving sulfuric acid microdroplets to reflect sunlight and drastically cool the planet. That took roughly a decade to clear, allowing the climate to return to something like normal.

[@YuriyKuzin]

Thank you for the tale. I fell asleep within a few minutes at night, and in the morning, I just listened to it again. :)

[@MongoosePreservationSociety]

Fantastic video

[@johnbreckbuhl2112]

Hello and greetings from Puerto Rico. You got my attention. I appreciate content like this.

[@samithpriyantha6125]

Your video is well arranged and easy to perceive.

[@AchanhiArusa]

There seems to have been a secondary 0.4 km impactor (Nicholson, et. Al.; "The Nadir Crater offshore West Africa); Science Advances v8 i33; 17 Aug 2022) and possibly a second and/or third (Chattterjee, et. al; :Shiva Structure"; Research Gate; Jan 2006) and five large pieces of secondary ejecta ((Premovic; "Iridium and the Chicxulub Impact Dust"; The General Science Journal 2020).

[@ElectronFieldPulse]

Thank you for the references. Do you know the time frame for the secondary impact and approximately how much energy it released?

[@AchanhiArusa]

I will have to look, but I read 1,000 to 30,000 years.

[@AbhijeetBorkar]

What's kinda weird is that the other major mass extinctions were primarily caused by volcanism, so it's a bit strange when some geologists dismiss the idea that this specific extinction wasn't caused by volcanism at all.

[@philochristos]

It must've been a horrific day for the dinosaurs that weren't immediately vaporized.

[@Booger-u6m]

"Bad hair day" doesn't start to describe it. Immediately after the impact, the entire planet would have rung like a bell. There would have been massive earthquakes everywhere for days afterwards, especially in the first few hours. Those just outside the immediate impact zone and fireball would have experienced quakes of up to 11. For comparison, the strongest earthquake on record today is 9.4. Each full point indicates a 10× increase in energy released, so a quake of 11 is almost 100× stronger than the strongest earthquake measured today. The ground would have literally rippled and rolled in waves several feet high. Standing up would have been impossible. Animals would have been thrown around like toys after you cannonball into your bathtub. The larger ones would have sustained life-threatening or fatal injuries. Then there's the pressure wave, a wall of high pressure air, similar to a nuclear blast (but MUCH, MUCH bigger!) that circled the entire planet several times in the hours after the impact. Anything within about 1000 km of the impact would have been picked up and thrown. Those a bit further out would've been knocked over and deafened. The asteroid hit in the ocean, so the entire water column would have been pushed up and out for 200 km in every direction. It's thought by some geologists that the resulting tsunamis were as much as 3,000 feet (950-1000 m) tall and would have rolled dozens to hundreds of miles inland along the coast of North America, with decreasing energy with increasing distance from the impact. All of that is just in the first 6 hours after impact. Over the next several days, debris thrown into suborbit by the impact would have rained back down. As billions of tiny pebbles fell, accelerating as they went, friction heated them to incandescence. In the lower atmosphere, this heat transferred to the air, causing it to heat beyond water's boiling point. Anything left unsheltered was roasted to death across much of the planet. The worst of this would have come in the first 24-48 hours, then tapered off. Yep, "bad hair day" doesn't begin to cut it. 😬

[@philochristos]

@@Booger-u6m I would think being burned alive would be the worst part of it. I'd rather shave my head than be burned alive. But it would've been a sight to see! Not my head, but the rest of it.

[@dargi_amorim]

16:35 If I remember correctly, this hypothesis is based on the fact that the place where the erruptions occured is not far from the antipode of the place where the asteroid hit Earth. The impact surelly generated massive seismic waves that propagated throughout the interior of the Earth, and these waves reached the other side of the planet and could have been focused in the antipode of the impact point, tranferring a lot of energy to the region where India was located at the time.

[@sassa82]

Such a interesting topic🎉

[@michaeleisenberg7867]

Hello Rachel 🌋☄️, This is an excellent drill down on the dinosaur 🦕 🦖 extinction. Thank you very much. 👏👏👏👏

[@nicholasmaude6906]

@GEOGIRL - A fun, interesting and informative video (As per usual), Rachel, I also like your new hairdo as I think it suits you and you look good with it😊.

[@danielpetersen6622]

I tend to think that the Deccan Traps were either started or intensified by the Chicxulub impact. The force of the impact propagated to its nadir, near where the Deccan Traps reside. Another (unproven) example can be seen on Mars. The Hellas impact basin is almost opposite of the Valles Marineris and the Tharsis bulge and volcanoes. The Vallis Merineris looks like the planet burst apart by the force from Hellas. So toss that idea in the peer-review pot and see if it boils!

[@sydhenderson6753]

India was still south of the equator 66 million years ago, so maybe.

[@Booger-u6m]

The rift volcanism that formed the Deccan Traps had already been erupting for several hundred thousand years before the impact. Afterwards, eruptive activity in that system seems to have increased for a time, then ceased entirely about 100k years later. This is a subject that needs further study.

[@jimscheltens2647]

I’ve always found it puzzling that creatures as fragile as birds survived the extinction event. Think ‘Canary in coal mine’, something so sensitive to change that it drops dead before miners even feel the effect. Burrowing mammals surviving makes sense, but flying warm blooded birds? How does that work?

[@wesdowner5636]

Birds (dinosaurs) have a 3 chamber heart, feathers and are partially "warm-blooded."

[@GEOGIRL]

I actually have a whole video about what characteristics helped birds survive! -> check it out here: kzbin.info/www/bejne/poeYmXaue7qHbsksi=Uya7B33S5bXvKu0N Turns out it was mainly their beaks & brains! :D But there are lots of other reasons that I mention in that video as well :)

[@Kennephone]

Most birds didn't make it, even most mammals didn't make it, but no dinosaurs made it.

[@fallinginthed33p]

@@Kennephone *while munching on chicken wings* I'm glad certain avian dinosaurs made it this far. There must have been a genetic bottleneck with most species across genera being wiped out.

[@toastyburger]

Birds and small mammals eat seeds. That's my favorite explanation, but see Rachel's video for more reasons.

[@connormcgee4711]

Hello, the genera biodiversity chart has appeared in a few videos, and I was wondering why there is a change in the rate of increasing biodiversity after the Permian-Triassic extinction. Were there forms of life which inhibited increasing biodiversity? Why is the increase more linear afterwards?

[@AncientWildTV]

i really enjoyed this video, the visuals and explanations were on point! but honestly, i can't help but feel that the whole asteroid impact theory might be oversimplified. i mean, what about the other factors like volcanic activity or climate change that could've contributed as well? it seems too easy to pin it all on one event. would love to hear what others think!

[@calinradu1378]

Well I think that just the volcanism wouldn't have wiped out the dinos. I think they went through more environmental stresses throughout their over 165 million years of existence. I think it's likely that even if they wouldn't have suffered the stress of the Deccan traps, which was perfectly reversible, they would still have been doomed by the asteroid. Or at best very very few of them would have survived, very hard to bounce back....

[@barryfennell9723]

Certain seeds will dehydrate and lay dormant until the land becomes viable again.

[@shadeen3604]

thanks Dr geo girl

[@rift8966]

I remember reading something about a decade ago which suggested that the dinosaurs were already struggling before the impact, and that the impact was sort of like a "nail in the coffin" for many of them. I think there was also something said about maybe a dinosaur disease or something? Dunno... Not sure what ever came about of those "theories", as I've not heard anything about them since. 🤷‍♂

[@billkallas1762]

The Deccan Traps were a massive volcanic eruption in India, (On its way North, to smash into Asia) that occurred at the same time (either just before, or just after), that would have put out massive amounts of CO2, that could have either started the extinction, or finished them off (It produced lave flows over a mile think) I believe that the Deccan traps were a major influence in the death of so many species.

[@dsracoon]

I can believe that hypothesis about the impact increasing volcanism, even in a totally different part of Earth. Such a large impact might have been very capable of "squishing" the Earth, causing stresses at the crust, and making areas that are prone to volcanism to make it easier for lava to flow out.

[@gaufrid1956]

I'm not a geologist but given the fact that the Deccan Traps were at the antipodes of the Chicxulub impact site at the time, I'd be willing to bet on the asteroid impact causing the volcanism at the Deccan Traps. There are a number of examples of volcanism happening at the antipodes of a major geological event. There was a large amount of volcanism happening in what is now Eastern Australia at the time of the major volcanism in the Siberian Traps during the Permian, for example.

[@tomgoss6401]

Excellent presentation. But did anyone else notice the mistake in the diagram starting at 1:10?

[@nicholasmaude6906]

My understanding, Rachel, is that the Dinosaurs only became dominant towards the end of the Triassic era after the Carnian Pluvial event.

[@MashupsByMandy]

THE ICE AGE! *shoots freezing energy gun*

[@qwertyuiop1st]

Oh good! I am watching these videos in the right order! I am inclined to assume that the Deccan Traps played _a_ role in the KT mass extinction, and my rationale for that is that the extinction was caused by - as this video shows - many different things going wrong as a consequence of the impact - the Deccan Traps fit into that observation as "another thing that went wrong".

[@questprotector]

if the asteroid had never hit, would the mesozoic have continued? also, does the whole gulf coast look like the rim of a crater?

[@TheBoxBand]

Something worth mentioning is the raise of ocean water due to increases in temperature. This event has two major impacts on marine life. First it decreases the amont of salts in ocean water. Second it changes the streams which leads to massive changes in weathers thus negative effects on life. Another thing that came to my mind is that how destructive global warming would be if we continue to change the environment around us. And it is very scary when you understand that us, humans are as equally dangerous as a 10 km astroid.

[@STho205]

So stop using your phone, your hair dryer, your car to go see concerts or friends, don't do unproductive leisure time activities like university, stop consuming beyond base survival eating, become an organic farmer and don't buy any more clothes till your current ones fall apart.... Easy.

[@TheBoxBand]

@STho205 why everything should be binary? One or zero. We can live our life in a way that damages the environment much less. Yes, i use my clothes until they are not usable anymore, i don't buy every new tech device that comes to the market. Human existence on this planet is destructive enough, we can decrease this destruction by limiting our consumption. That's all.

[@NachtmahrNebenan]

I love the diamond 💎 in the word diamond on the one slide 🤩 (Yes, I know it's your pointer)

[@phenylalanine1042]

It could be argued that termites , ants, nematodes, etc were and are the dominant land animals.

[@wendydelisse9778]

Another factor in the mass extinction was river and ocean water quality. At first, a lot of impact dust either settled directly on the water surface, or else was easily eroded into rivers. Gills of some water breathing vertebrates would get impeded. Also, water opacity would be reduced, reducing the amount of aquatic and marine photosynthesis, making the base of the food chain much less productive. Conceivably, it might have taken about 1,000 years for airborne spores of ferns to put enough plant cover on bare regions of land to allow water quality in the ocean to return to roughly normal values, and allow photosynthetic marine organisms to be drifting in sea water that had enough transparency to sunlight to be able to get enough sunlight to be able to thrive again. On land, ferns would have temporarily been the dominant plant life, since their microscopic spores would carry so well in the wind to spread to regions that had been made barren by the meteorite strike. A lot of creatures that had previously eaten other types of plants might have found ferns to be poisonous. Mammals had an unusually large liver in comparison to other warm blooded creatures to help with neutralizing unaccustomed plant toxins, and so would have had an advantage over other warm-blooded creatures that attempted to eat whatever species of green plants remained in a region. Something else that would had help cause changing in which plant species dominated in some regions is that large dinosaurs were no longer there to make footprints sufficiently broad and deep to help with rainfall retention, a footprint-leaving role that elephants now play in parts of Africa and Asia. Some species of plants would have been more able to take local advantage of improved water reliability of such footprints than others. Without those large water-retaining footprints for many tens of millions of years, those opportunistic plant species would have suffered, allowing other plant species to become predominant. Short version: Barren post-impact stretches of land with greatly reduced plant cover caused erosion that led to an extended time of unusually dirty ocean water, interfering with marine photosynthesis. Also, by way of the temporary scarcity of plants on land helping to kill off by way of starvation land vertebrates that had formerly left large rain-retaining footprints, when plant cover finally returned, a different set of predominant plant species was guaranteed in some areas by lack of those large footprints as a source of reliable water. In other areas a different plant predominance pattern was guaranteed from ferns being much more wind-spreadable than other plant types. Some creatures simply wouldn't be able to adapt to their formerly favored plant species to graze upon being much harder to find with their previous grazing range, or simply no longer being there at all to find within their previous grazing range.

[@CitiesTurnedToDust]

Okay - I admit it. It was ME! HAHAHA... and I'd do it again!!

[@tedetienne7639]

Great video! Thank you! Could you please tell us the source of that Big 5 Mass Extinction graph at about 35 seconds into the video? It's a bit different than the one I became familiar with. I specifically notice that the Late Devonian Extinction is a much more prolonged event than was believed before to occur - not the sharp drop-off that was once depicted. I need to keep up to date with these things! Thanks!

[@d012k-n5t]

Oh? You change the background, what does the cat think LOL

[@philochristos]

Good morning!

[@sydhenderson6753]

One of the reasons the Permian extinction was so bad is thought tp be chlorine compounds released from the Siberian Traps destroying the ozone layer. Could something like that have contributed to the KT* extinction or would the dust in the atmosphere actually protect life? *I'm old-school.

[@NavajoMX]

Growing up, I remember my dino books saying they died 65 million years ago, and now all science education materials say ~66 million. Either time flies, or the science got updated!

[@GEOGIRL]

Yep! The science continues getting updated as we get more and more precise radiometric dating techniques :D Actually, there are so many boundaries in the geologic timescale that are defined at about 1 million years earlier or later than they were a few years ago because we are going back through the rock record now with more precise methods and correcting these boundary dates :) The precambrian to cambrian is another they've changed a lot (from 540 to 542 to 541 to 541 point something haha) ;)

[@briebel2684]

The volcanic activity probably had created some stress factors on some forms of life. Probably not all forms though. The ones that were capable of adapting were probably already doing so. Might have even made some forms a bit more resilient.

[@charlesmartin1121]

Actually it is hypothesized that modern sharks (both Carchariniformes and Lamniformes), which had an adaptive radiation in the Cretaceous, had already replaced the Ichthyosaurs by about 100 million years ago.

[@ionlytalkboxing3648]

I know there were a series of events in conjuction after the impact that ultimately killed the dinosaurs. I'd like to know if most non avian dinosaurs were killed within 24 hrs of the impact.

[@GEOGIRL]

Nope, probably not. While we cannot get down to the day in precision with radiometric dating, it is unlikely that the non-avian dinosaurs went extinct within the first 24 hrs after impact. This is because the most devastating effects of the impact (globally) occurred over a period of days to weeks (the re-entry heating), then months to years (impact winter and lack of photosynthesis), and then 100,000s of yrs (greenhouse induced global warming). It is likely the dinosaurs declined at every step, but probably took 100,000s of yrs to go completely extinct at the KPg boundary. Hope that helps! :)

[@oceanmapper8502]

Thank you for your video. You talked about the fossil record after the asteroid impact event but you did not mention anything about what the fossil record showed just before the impact event. What were the fossils in the record layers just before the impact event so that we may understand which of the dinosaurs were impacted by this event. Also please let us know what were the fossils that are buried in the actual impact event layer that show they were killed by the impact. Thanks again. Regards.

[@nickfosterxx]

I mean, I knew it was bad - being roasted alive by the sky glowing like a grill, then the dark and the cold, the acid rain... but heck it was so much worse. Thanks for enlightening me. When I was a kid we had scary bedtime stories about witches and stuff. Guess I'll be telling kids about the asteroid. Then at the very end I'll say it was like half the size of a pinhead compared with basketball earth. Edit: pinhead diameter, 0.5mm, basketball 240mm. Asteroid diameter 10km, Earth, 12,700km.

[@b.a.erlebacher1139]

There were some especially awful effects due to the meteor hitting this particular spot where it struck an immensely thick deposit of calcium carbonate, causing a great increase in atmospheric CO2, resulting in a big increase in temperature world wide. Had the meteor struck just an hour or so later, it could have hit the depths of the Atlantic Ocean, and the overall effect would not have been quite so immensely catastrophic - no worldwide continental fires, no great change to atmospheric composition, no effect for many years on level of photosynthetic sunlight, etc.

[@carolynallisee2463]

It certainly makes sense that the Chicxulub impact wasn't the only event involved in the KPg Mass extinction. I'm not sure why our species tends to think in such terms, but we seem to be obsessed with the all encompassing, singular cataclysmic disaster, when in fact, many of the major events are actually made up of a lot of smaller ones. Even the Siberian Traps CFB (Continental Flood Basalt) eruptions weren't just one single vast eruptive event, but many, many smaller ones that took place over the course of a million years. This is why I find all those people who scream about Yellowstone and the 'End of the World' so annoying. The simple truth is that no matter how big an eruption Yellowstone produces ( and right now it's as far from doing that as it could possibly get), it isn't going to destroy the world, no matter how many proclaim it will. I caught another video this evening which talked about a period of super-volcanic eruptions in the US West, which not only didn't cause a mass extinction, it didn't seem to do much of anything but preserve a very good snapshot of the fauna and flora living in America at the time... and many of these individual eruptions were many times bigger than the largest of the Yellowstone ones. So sorry, boys and girls, Yellowstone won't bring about the End Times. Not only is there no sign it will produce a super eruption next time it erupts (and its showing no signs of producing any kind of eruption in the foreseeable future), but even if it did, the world will carry on as always. Sure, America won't come out of it well, and the rest of us will have a very hard time during the aftermath, but the world will go on. It will take something far more devastating than that to finish good old Earth off!

[@michaelsimpson4099]

Could the shock wave created by the Astroid have displaced the tectonic at the other side of the world?

[@billkallas1762]

No.

[@sagittarius_a_starr]

i think we have the same interior decorator

[@rj-zz8im]

Has anyone looked into the possibility that the past large impact craters were left overs from the planetary collision and creation of the Moon? Also, could volcanic hot spots be a result of impacts on the opposite side of the Earth?

[@nicholasmaude6906]

So basically right after the impact in the area around the impact site it was basically raining battery-acid.

[@TagiukGold]

Top KZbin geology personalities, not in any order: Rachel Phillips, Alexis Dahl, Dan Hurd

[@ecocentrichomestead6783]

Just 4.5 mins in but thanks for sharing. I have been saying, in conversation about the current climate change, that the asteroid impact wasn't what killed off the Dinosaurs. And the extinction of the dinosaurs was not what gave mammals a chance to evolve. The earth never returned to the environmental and climatic conditions the caused life to evolve into Dinosaurs. Rather the new earth conditions favored the mammal and warm blooded species we have today. This has big implications WRT the current climate change. Humans will have to evolve (change into something else) with climate change or go extinct. Technology will not save us.

[@GraniteGhost778]

Maybe you'll address this in the video, but can you explain why the timeline changed from 65MYA to 66MYA? Did the date get revised at some point? I don't know why this change happened, just that suddenly all my dinosaur sources started using 66 instead of 65.

[@metal--babble346]

Dinosaurs had tiny brains. They didn't even have cell phones. Humans are smart, therefore the big asteroids are choosing not to hit planet Earth.

[@raybod1775]

Your logic is impeccable!

[@fredi9204]

I think if you were carnivore that lived in a cave which has access to spring water, you'd have had good chance to get through the first week after which you lived in a fried meat freezer. I mean of course a species would still go extinct if it wasn't big on incubating eggs when the temperature dropped. The last t-rex probably died childless and of obesity - a looming fate for humanity too. My hypothesis is that slow-metabolism species like crocodiles made it through due by first eating megatons of meat, and then cannibalized each other for thousands years in literal Hunger games. Pterosaurs were much cooler than birds, but waxy feathers could fry in the infrared furnace creating a protective carbon shell while pterosaur-fluff flash burned to the skin folds that blistered and leaked all the body fluids over hours or days of horrid endless pain. Quite terrible

[@p57-elf]

1) Decan Traps for millions of years a mild release of toxicity 2) Decan Traps part 2 this was more violent and basically killed the Dinosaurs 3) Chicxulub appeared when everything was just about dead and the volcanoes had finished their work..This is kind of like the standard model in physics!!!

[@mawkernewek]

0:35 invest in the stock market. the graph goes up in the long-term!

[@coweatsman]

Those dinosaurs close to ground zero were the lucky ones.

[@jongrover8763]

I wonder sometimes if the asteroid caused the Deccan traps as an antipodal effect. I think this has been disproven but I still wonder.

[@mikeg2306]

When you're talking about sinkholes in the Yucatan, do you mean cenote? I know cenote were a major source of water for the Maya, but could they be that old?

[@allengrantham6693]

Didn't iceland erupt at theat time? I read that the astroid calved and there were multiple impacts one of which led to the formation of the iceland volcano.

[@robertab929]

*Dinosaurs are still with us.* So the question what killed them does not make sense. It should be rather "What killed Non-Avian Dinosaurs?"