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.
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.
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.
@@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
@@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.
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!
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!
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!
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! 💃
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.
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)
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.")
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.
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❤ 🦕
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?
I actually have a whole video about what characteristics helped birds survive! -> check it out here: th-cam.com/video/pV5hCxFUT8g/w-d-xo.htmlsi=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 *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.
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 🙂
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. 🦖🦕
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).
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.
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_ . 🥰
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?
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.
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?
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?
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.
"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. 😬
@@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.
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!
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!
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. 🤷♂
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.
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.
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?
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....
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!
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) ;)
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".
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.
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.
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.
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.
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.
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!
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?
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.
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! :)
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.
I seen other information that there may have been more than one asteroid impact at the time. Off the coast of Africa and in Russia. Do you have any information on this theory?
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.
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
I love your videos, but this subject is a major interest of mine: the dinosaurs were not killed, at least not in any different way than reptiles and mammals. There were several groups of dinosaur survivors, just as with mammals. We just happen to retrospectively call the surviving dinosaurs “birds”. (It’s as if we stopped calling the surviving mammals “mammals” and called them “fluffies”). For good reasons small beaked flying dinosaurs survived, and they now outnumber mammals in terms of species.
It's only fairly recently that it's been established that birds descend from dinosaurs. There was a very large and diverse population of birds, but most likely only a few species survived, possibly only 3 or 4, all of the same lineage, a group without teeth that possibly mostly ate seeds, really only three lineages that originate all living birds.
Apparently more than one lineage of birds, and more than one lineage of mammals. And, alas, no ammonites or non-avian dinosaurs. But at least we still have crocs!
LOL... My two cents say... I agree it was a massive pile on and a mega bad day that lasted years. I think dinosaurs could not get as big as they did on modern oxygen levels. The higher oxygen level, the massive plant life. and the incredible heat from impact created the worlds biggest Fire Triangle.. .. these fires would be unlike anything seen in modern times. I think it would be hard to over estimate how destructive they were. and as oxygen was used up dinosaurs and other large animals that survived the impact were hard put to survive. .. which was escalated by the domino events you list. I know some dinosaurs seem to have been dying off before the impact... maybe volcanism was a contributing factor especially if it was worse in the old world....kinda spreading around the mayhem . The fact that really large Dinosaurs never come back makes me suspect the change in oxygen is at least partly true. Thanks for a really interesting video...
I see feathered birds, hairy underground mammals and submerged lizards survived the event and selected so was there a winter which endothermic animals it ones with coat and water specificity survived while cold blooded especially the large ones perished??
What I think is funny is that the animals that replace other animals in the same nishes tend to look smilar, or is that just because we imagine them that way?
tl;dw: Too hot, too dark, too cold, too hot, too sour. Although I’m sure the research opportunities would be amazing, I wouldn’t want to live through that period.
antipodal volcanism : Big shock on one side of the planet (asteroid) travels around the crust and blows out a weak point in the crust on the other side and starts volcanoes.
Were the dinosaurs killed off by an asteroid impact, volcanism, impact winter, toxic gases, CO2 release, ocean anoxia, acid rain, or ocean acidification? YES!
It is now discovered that there were more asteroids in the K-T boundary 5th extinction event. This could be considered up to the level of a nearby (super)nova and the star core fragment et al were shotgunned all over the cosmos. The Gulf of Mexico Yucatan Chicxulub asteroid impact zone of 110 miles x 110 miles, with an asteroid of 6 miles diameter that is buried 12 miles deep. There is now the strong statement that Mount Olympus of the Washington state Olympic National Park, an ancient volcanic island arc landmass of Siletzia from (modern) Washington state down to Northern California was another asteroid hit and hotspot, that eventually travelled up the Columbia River Basin and the Snake River, ending up against the Rocky Mountains as the (now) Couer dAlene lake (much like the volcanic Mount Mazama (Crater Lake) of Oregon. The Siskiyou-Klamath mountain range at the Oregon-California border houses another massive asteroid hit that still has 5 super magma chambers of the same size as Yellowstone's 5 super magma chambers - that would also be considered and asteroid impact and trail of volcanic eruptions from Nevada up to Wyoming/Montana of Yellowstone in the Rockies. The famous Skinwalker Ranch, sitting in the Uintah Basin, southeast of Salt Lake City, is the same size as the Yucatan asteroid, with the same impact zone of 110 x 110 miles, and the near-same 6 mile diameter asteroid, buried 3-4-6 miles deep. Nearby and southwest of Skinwalker Ranch is Blind Frog Ranch that has a smaller sibling asteroid, that followed the Uintah Basin asteroid to the Earth, that lies buried some bare 100 feet deep at the surface. The Long Valley caldera in the Central Valley of California ~could~ be considered an asteroid impact and later hot spot volcano. All of these hit at the Cretaceous-Tertiary boundary (K-T boundary) of ~65 MYA as the 5th extinction. But, latest paleozoic findings and analysis are showing that the surviving weaker biological plants, insects, fish, reptiles, amphibians, birds, and mammals through this event came through, while the bigger dinosaurs died off. This goes to saying for various reasons the dinosaurs were dying off in successive periods before the asteroid extinction event. It is also now known that all such (said) 5 major extinctions (and 100+) minor extinctions were caused by Earth being in a different solar system in the galactic arm, underwent such (super)novas, and was then flung out into space. Earth became a rogue planet, eventually captures by successive solar systems, further and further out on the galactic arm. These were cosmic events, not planetary or human made situations.
Some people assert that it's happening now at a rapidly increasing effect of human activity, both the destruction of most natural ecological areas and the current increasing disastrous effect to climates triggered by increase of CO2.
Actually, toothed birds that ate insects, didn't survive. Beaked birds that ate insects AND seeds, did survive, when the insect population was diminished.
It's not like I'm taking notes or anything, but your videos always feel like proper lectures. Like I'm getting an education.
Yep. Quality output made with passion.
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.
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.
They are… except we don’t have to enroll or pay anything. 😎
Hot for teacher
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.
Ayyy I am an invertebrate paleontologist specializing on the KPg boundary, this is very well done and accurate, nice work 👍
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
I know you specialise in KPg boundary but what's your favorite Cambrian animal???
as an invertebrate expert don't you take issue with the claim that dinosaurs were the dominant land snimals - ants, termites, nematodes, etc?
@@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
@@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.
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!
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!
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!
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! 💃
Congrats on the science communicator job. It's about time you got recognized for all your great work in this field. Legend!
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.
Oh my gosh! I didn't know that, that is so impressive :D
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)
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".
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☆ 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.")
Very Informative as usual, thank you Professor Rachel. 😀
Great video such a fascinating topic❤
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.
Enjoy learning from your videos. They are informative and well thought out. 😊
What a fascinating subject! Thanks, Rachel. ☄🌋🙌
Thank you for the fantastic content. 👏👏
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❤ 🦕
Geo Girl always enlightens us. ❤🎉😊
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?
Birds (dinosaurs) have a 3 chamber heart, feathers and are partially "warm-blooded."
I actually have a whole video about what characteristics helped birds survive! -> check it out here: th-cam.com/video/pV5hCxFUT8g/w-d-xo.htmlsi=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 :)
Most birds didn't make it, even most mammals didn't make it, but no dinosaurs made it.
@@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.
Birds and small mammals eat seeds. That's my favorite explanation, but see Rachel's video for more reasons.
Check out the part 2 here:th-cam.com/video/cpu74BpWXvY/w-d-xo.html ! ;D
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 🙂
Great video Rachel 👏!
Thanks for posting/sharing with us!! Stoked to see part two!! 🍻
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. 🦖🦕
Another certified banger ☄️💥🌊🔥☁️🌡️
I can tell you're a good geologist, because you bring your work home with you and use it to decorate.
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).
Dr Rachel your lectures are very informative. I am a geology graduate and learn a lot of geology knowledge from your videos.
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.
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.
Great video. Very informative and easy to follow.
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_ . 🥰
Exceedingly well-done GeoGirl...finna check out part two❤👍
Thank you for the tale. I fell asleep within a few minutes at night, and in the morning, I just listened to it again. :)
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?
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.
Thanks, another great video, :)
Fantastic video
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?
How many decades ago??
Hello Rachel 🌋☄️,
This is an excellent drill down on the dinosaur 🦕 🦖 extinction. Thank you very much.
👏👏👏👏
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?
Definitely, probably not quite the same as a pyroclastic flow but enough to kill
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.
Love the video Rachel. Your channel is great for people like me that have a big interest in geology & paleontology 😘
I love your videos so much! Excitingg details!
It could be argued that termites , ants, nematodes, etc were and are the dominant land animals.
Such a interesting topic🎉
It must've been a horrific day for the dinosaurs that weren't immediately vaporized.
"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. 😬
@@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.
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!
India was still south of the equator 66 million years ago, so maybe.
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!
THE ICE AGE! *shoots freezing energy gun*
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. 🤷♂
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.
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.
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?
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....
Thanks!
Thanks so much! ;D
if the asteroid had never hit, would the mesozoic have continued? also, does the whole gulf coast look like the rim of a crater?
Good morning!
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!
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) ;)
Oh? You change the background, what does the cat think LOL
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".
I love the diamond 💎 in the word diamond on the one slide 🤩
(Yes, I know it's your pointer)
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.
Certain seeds will dehydrate and lay dormant until the land becomes viable again.
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.
Your logic is impeccable!
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.
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.
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.
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.
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!
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?
Could the shock wave created by the Astroid have displaced the tectonic at the other side of the world?
No.
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.
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! :)
5:42 If this explosion really happened, I don't know if I would still be here commenting🤣🤣🤣
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.
I seen other information that there may have been more than one asteroid impact at the time. Off the coast of Africa and in Russia. Do you have any information on this theory?
Those dinosaurs close to ground zero were the lucky ones.
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.
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
I love your videos, but this subject is a major interest of mine: the dinosaurs were not killed, at least not in any different way than reptiles and mammals. There were several groups of dinosaur survivors, just as with mammals. We just happen to retrospectively call the surviving dinosaurs “birds”. (It’s as if we stopped calling the surviving mammals “mammals” and called them “fluffies”). For good reasons small beaked flying dinosaurs survived, and they now outnumber mammals in terms of species.
" We just happen to retrospectively call the surviving dinosaurs “birds”."
Fluffies survived bc they're cute
It's only fairly recently that it's been established that birds descend from dinosaurs. There was a very large and diverse population of birds, but most likely only a few species survived, possibly only 3 or 4, all of the same lineage, a group without teeth that possibly mostly ate seeds, really only three lineages that originate all living birds.
Apparently more than one lineage of birds, and more than one lineage of mammals. And, alas, no ammonites or non-avian dinosaurs. But at least we still have crocs!
I'd say it's more like only rodents and we ended up calling their descendants (most of whom learned to fly) fluffies.
*Dinosaurs are still with us.* So the question what killed them does not make sense.
It should be rather "What killed Non-Avian Dinosaurs?"
LOL... My two cents say... I agree it was a massive pile on and a mega bad day that lasted years. I think dinosaurs could not get as big as they did on modern oxygen levels. The higher oxygen level, the massive plant life. and the incredible heat from impact created the worlds biggest Fire Triangle.. .. these fires would be unlike anything seen in modern times. I think it would be hard to over estimate how destructive they were. and as oxygen was used up dinosaurs and other large animals that survived the impact were hard put to survive. .. which was escalated by the domino events you list. I know some dinosaurs seem to have been dying off before the impact... maybe volcanism was a contributing factor especially if it was worse in the old world....kinda spreading around the mayhem . The fact that really large Dinosaurs never come back makes me suspect the change in oxygen is at least partly true.
Thanks for a really interesting video...
What happened before the asteroid impact is also important
thanks for the video Dino's rock i like to think Canadian Geese are some of our last true decendents of dinos the way they act lmao very angry.
I see feathered birds, hairy underground mammals and submerged lizards survived the event and selected so was there a winter which endothermic animals it ones with coat and water specificity survived while cold blooded especially the large ones perished??
Also crocodilians hiding in rivers and burrows.
"They went extinct as well *chuckle*". So quirky :)
What I think is funny is that the animals that replace other animals in the same nishes tend to look smilar, or is that just because we imagine them that way?
It’s true! That’s called convergent evolution :)
A series of unfortunate events 🤔
If the asteroid didn't do it, the Dekkan Traps probably would have
I want to point out that Dr Freeze told us that the Ice Age killed the dinosaurs. And he's a doctor.
I wonder what parasites survived kt.
Those poor dinosaurs :(
0:35 invest in the stock market. the graph goes up in the long-term!
tl;dw: Too hot, too dark, too cold, too hot, too sour. Although I’m sure the research opportunities would be amazing, I wouldn’t want to live through that period.
antipodal volcanism : Big shock on one side of the planet (asteroid) travels around the crust and blows out a weak point in the crust on the other side and starts volcanoes.
Poor dinosaurs, they never did nothin to nobody 😥
Were the dinosaurs killed off by an asteroid impact, volcanism, impact winter, toxic gases, CO2 release, ocean anoxia, acid rain, or ocean acidification? YES!
All of the above.
It is now discovered that there were more asteroids in the K-T boundary 5th extinction event. This could be considered up to the level of a nearby (super)nova and the star core fragment et al were shotgunned all over the cosmos. The Gulf of Mexico Yucatan Chicxulub asteroid impact zone of 110 miles x 110 miles, with an asteroid of 6 miles diameter that is buried 12 miles deep. There is now the strong statement that Mount Olympus of the Washington state Olympic National Park, an ancient volcanic island arc landmass of Siletzia from (modern) Washington state down to Northern California was another asteroid hit and hotspot, that eventually travelled up the Columbia River Basin and the Snake River, ending up against the Rocky Mountains as the (now) Couer dAlene lake (much like the volcanic Mount Mazama (Crater Lake) of Oregon. The Siskiyou-Klamath mountain range at the Oregon-California border houses another massive asteroid hit that still has 5 super magma chambers of the same size as Yellowstone's 5 super magma chambers - that would also be considered and asteroid impact and trail of volcanic eruptions from Nevada up to Wyoming/Montana of Yellowstone in the Rockies. The famous Skinwalker Ranch, sitting in the Uintah Basin, southeast of Salt Lake City, is the same size as the Yucatan asteroid, with the same impact zone of 110 x 110 miles, and the near-same 6 mile diameter asteroid, buried 3-4-6 miles deep. Nearby and southwest of Skinwalker Ranch is Blind Frog Ranch that has a smaller sibling asteroid, that followed the Uintah Basin asteroid to the Earth, that lies buried some bare 100 feet deep at the surface. The Long Valley caldera in the Central Valley of California ~could~ be considered an asteroid impact and later hot spot volcano.
All of these hit at the Cretaceous-Tertiary boundary (K-T boundary) of ~65 MYA as the 5th extinction. But, latest paleozoic findings and analysis are showing that the surviving weaker biological plants, insects, fish, reptiles, amphibians, birds, and mammals through this event came through, while the bigger dinosaurs died off. This goes to saying for various reasons the dinosaurs were dying off in successive periods before the asteroid extinction event.
It is also now known that all such (said) 5 major extinctions (and 100+) minor extinctions were caused by Earth being in a different solar system in the galactic arm, underwent such (super)novas, and was then flung out into space. Earth became a rogue planet, eventually captures by successive solar systems, further and further out on the galactic arm. These were cosmic events, not planetary or human made situations.
oh no i love her
I am excited for the next mass extinction. Like to know what it will be but not actually experience it.
Some people assert that it's happening now at a rapidly increasing effect of human activity, both the destruction of most natural ecological areas and the current increasing disastrous effect to climates triggered by increase of CO2.
They lived on CO2 but eating plants that was making oxygen. Than it ran out CO2 and died all at once.
Animals that ate insects and seeds survived.
Actually, toothed birds that ate insects, didn't survive. Beaked birds that ate insects AND seeds, did survive, when the insect population was diminished.