Were Dinosaurs Dying Or Thriving Before Their Extinction?

For years, paleontologist and onlookers were only concerned about the day the dinosaurs died, which was brought upon them by a giant asteroid. And no one was asking about how they were doing right before the collision, that is until recently, when new research suggested that dinosaurs may have actually already been going extinct. This spawned an entire new debate, which has now lead to two schools of thought, both with their own supporting evidence, which raises the question: who is right?
Thumbnail: Liscianigiochi
Copyright Disclaimer under Section 107 of the copyright act 1976, allowance is made for fair use for purposes such as criticism, comment, news reporting, scholarship, and research. Fair use is a use permitted by copyright statute that might otherwise be infringing. Non-profit, educational or personal use tips the balance in favour of fair use.
Sources:
www.thehindu.com/sci-tech/sci....
www.smithsonianmag.com/smart-...
www.nature.com/articles/s4146...
theconversation.com/dinosaurs...
www.nhm.ac.uk/discover/news/2...
www.newscientist.com/article/...
www.cnn.com/2020/11/18/world/...
www.imperial.ac.uk/news/19044...

[@waranontwiwaha9385]

It’s almost impossible for an entire clade of animal (dinosaur as a whole) to go extinct without mass extinction event. On genera or families level? Sure, it happened all the time, but there will always be other more adaptable dinosaurs to later evolved and fill those niches. It took a devastating event that turn ecosystem up side down to wipe them all (and even then, birds still survived).

[@HOLA-zk9oh]

Yeah even then dinosaurs still survived in some way.

[@Magneticlaw]

Indeed. Just as an example, the T-Rex is believed to have filled two different niches, much like Komodo Dragons.

[@Acridotheresfuscus]

Ikr

[@beastmaster0934]

Yup. Take the faunal turnover with the ceratopsians for example. For most of the Cretaceous, centrosaurines were the dominant large ceratopsians of North America. But eventually, they were overtime replaced by the chasmosaurines. Same with the hadrosaurs. Lambeosaurines were dominant, but then they were largely supplanted by the saurolophines. It’s a given that, over time, small extinction events and faunal turnovers will occur, and species and genera will be replaced by others.

[@mitchellskene8176]

If I'm not mistaken, outside of North America, they seemed to be thriving. To my knowledge, North America is the only region where there was a noticeable decline in the number of species present in the 10-15 million years leading up to the asteroid impact.

[@mariomouse8265]

Even so, it doesn’t account for the preservation bias of the fossil record Jungles and Mountains are lousy places for fossil formation for example - we don’t find many mountain-dwelling dinosaurs as compared to Dinosaurs that lived in swampy marshland or scrubland

[@rumski2926]

also they still where very amazing like triceratops and trex even tho they were less diverse

[@Rabbit-o-witz]

America was hell way before humans? Huh

[@thenerdbeast7375]

If I had to guess why it is because some dinosaurs like hadrosaurs, ceratopsians and tyrannosaurs were so successful they dominated the ecosystem due to favorable conditions. Likely these species would have diversified due to competition if they had time.

[@mitchellskene8176]

@@Rabbit-o-witz Between Appalachia and Laramida combining, and the Rockies beginning their uplift, you could say that yep!!

[@Kodiie]

“Every one asked how I died, but no one asked how I was doing😢” Said the T-Rex struggling to wipe a tearful face with a tissue.

[@jeffreymorgan8687]

I just imagine a T. rex on a therapy cough. Blowing his nose, saying that.

[@Justmonika6969]

Both sides are kind of right. Low diversity has its pluses too. The T-Rex was a really dominating predator that would've made short work of Triceratops ancestors meanwhile the Triceratops did the same to the T-Rex ancestors. The lower diversity is down to the competition: the species that did exist were really good at what they were good at.

[@gshaindrich]

the bigger they are , the harder they fall: The low diversity is partly easily explainable, with adult specimens being massive while, there was a physical size constraint to the eggs, this meant that e.g a single sauropod species will have filled multiple herbivore niches with all of its growth stages. The same applied to carnivores.

[@scambammer6102]

there were lots of small dinosaurs. don't they count?

[@gshaindrich]

@@scambammer6102 firstly "diversity" counts species not individuals! If you do talk about species, how do you know there were "lots" if only a handfull non aviana dinosaur species have EVER been found OVER HUNDREDS OF MILLIONS of years!

[@scambammer6102]

@@gshaindrich I wasn't talking about individuals. Your comment is about large dinosaurs. I just noted that many (most) dinosaur species were small.

[@gshaindrich]

​@@scambammer6102 why don´t you take some time to read again and actually UNDERSTAND what I initially commented? Did I claim there was Low diversity? -> NO! I commented on THEIR statement in the video! Did I claim there where no small species? -> NO! Did I claim all dinosaur species at that time were big? -> NO So don´t put words in my mouth, when you yourself are just unable to grasp the meaning of my comment! I´m not sure if I should take the time to explain to you what I meant, when it seems like you will not understand it. Definitely no need to repeat what I already wrote! Don´t try me, when YOU are the one with less knowledge of ecology! Please read again, and NOT ONLY the first line. We can discuss it, after that.

[@Acridotheresfuscus]

This theory seems very unlikely. It's like saying the homo genus is going extinct. Many species were going extinct. But more species of dinosaurs would've evolved to fill in the extinct ones niche. And many were super successful too like the Tyrannosaurus Rex. Another thing is that most things don't fossilize.

[@gshaindrich]

If there was ever a species going towards extinction it is T. rex! If it even was "successful" in its day is questionable. To big to run, high mortality as adult, narrow distribution, also the single species in its genus, which lived for ~2mya, and all other genus of its family having ever shorter life spans ... if that sounds successfull to you ... something is wrong.

[@Acridotheresfuscus]

@@gshaindrich I was giving an example. T.rex's population was an estimated 3 billion. There weren't as much dinosaurs as before but the ones that were there were successful. T.rex would've gone extinct eventually like every other species but a new dinosaur species would evolve to fill it's niche.

[@Acridotheresfuscus]

@@gshaindrich "To big to run" it didn't really need to run. It was probably an ambush predator.

[@Acridotheresfuscus]

@@gshaindrich "shorter lifespans" A tiger's life span is 10-15 years and tigers are still successful.

[@jackwalters5506]

@@gshaindrich High adult mortality rate was a good thing. The reason many dinosaurs had lower adult mortality rates is because most of them died before reaching adulthood, the fact that most T-Rex died as adults means that they were highly successful at surviving throughout all stages of life

[@kade-qt1zu]

Yeah, I don't think so. Maybe some dinosaur groups were going extinct, but non avian dinosaurs as a whole would probably still be around.

[@cchavezjr7]

Species of dinosaurs have been going extinct, evolving and being created constantly for 3 periods. It seems "ideas" come up just got get views.

[@calessel3139]

There's a difference between a mass dinosaur die out event which afterwards sees various new genus of dinosaur replace those that dominated niches before, and a complete extinction of the dinosaur clade. In the late Cretaceous dinosaurs may have been heading towards a natural mass die out but I doubt the dinosaur clade would have gone extinct with out the asteroid impact.

[@domination1985]

I mean just because there's not a lot of diversity doesn't mean that there was a problem it means that the ones that were in charge or they are actually worked so they didn't need to diversify. but that can fight them in the but when something bad happens they can't hold on. because there's not as many different species too you know fill in the gaps.

[@Acridotheresfuscus]

Its like saying the homo genus is in decline.

[@justskip4595]

Are mammals going extinct now? Many species died off in last few thousand years with the climate change of ice age followed by explosion of humans populating the continents and spreading many other species with them. I could continue by saying same things as others in the comments and ones mentioned in the video, but those have already been said. I'd rather point out that birds are still around and have speciated to occupy many different ecological niches. Asteroid hitting at vulnerable moment may be true, but it does not equate that inevitable extinction was going to come anyway. Perhaps dinosaurs were even better suited to try to survive the extinction than they would have with higher number of species and they still didn't make it beyond birds.

[@hia5235]

Yes the Ice Age wiped out many many species. Cold climate never can support as much life: and the world is very very cold compared to the age of the Dinos.

[@erikbosma8765]

If humans and whatever animals and plants they took with them went extinct today, in a few lousy million years or so, there would be a garden here again and many new better species would dominate and hopefully learn to live in harmony like the humans almost did before they let out the Eurasians. Way to go Leif! Way to go Christopher! It's so sad that the indigenous races of the world didn't invent metals and metal working long before the Eurasians did. Who'd have the guns then, eh? Only 'problem' in that scenario would have been the fact that none of the indigenous peoples would have been using the metal as plow shares instead of swords and the Eurasians would have made short work of that.

[@oreolaw9911]

I am loving your videos I don't know what it is about you or your videos but you are probably my favourite small KZbinr making these sort of videos

[@ExtinctZoo]

Thank u :D

[@TheaSvendsen]

That was an awesome video and you went through everything that I’ve been wondering about. Saving this for my fellow dino nerds :D

[@Crakinator]

The dinosaurs were the absolute dominant clade in their time. They weren’t getting replaced without a devastating mass extinction event. There’s nothing they could have done to survive the meteor, they just died in a very unlucky, but admittedly pretty badass way.

[@veggieboyultimate]

I don't think the dinosaurs were on their way to extinction, more like a temporary population decline and would have recovered fully if not the meteor hit the Earth.

[@badartgallery9322]

Such great content.

[@lindagodfrey9994]

Obviously they were dying out even before because of the Deccan traps

[@Carnidoom]

So good content. Def gonna sub as ypu take specific topics xan i mke a suggestion? If you could make a video bout if triassic animals lived after triassic and into jurrasic like when they truely died out

[@ExtinctZoo]

Yes, I have been wanting to do more Triassic related videos.

[@globin3477]

Even if they were doing poorly, the non-avian dinosaurs would probably still have survived if the asteroid hadn't hit.

[@MrJmd116]

Can you do a video about the dinosaurs of Appalachia? All the vids I can find are long webcam discussions

[@Korb-Bee]

Mammals were far more diverse in the late Eocene than today but doesnt mean we are on our way out.

[@Korb-Bee]

(altho we might be due top humans)

[@panos617]

In some cases some species have hard times and others didn't.

[@VictorianTimeTraveler]

Everyone wants to know what dinosaurs were nobody ever asks how the dinosaurs were :´(

[@Novusod]

I believe it was a combination of the Chicxulub impact and the Decan Traps that knocked out the dinosaurs. The Chicxulub impact occurred 66million years ago. Dinosaurs somewhat hung on for another 1 million years. Then the Decan Traps finished them off.

[@SharksandDinos]

Except that the worst phase of the Deccan Trap eruption (which is the second phase) started 66.29 million years ago during the Maastrichtian Age of the Cretaceous period and ended 65.552 MYA during the Danian age of the Paleocene epoch. Meanwhile the Chicxulub asteroid struck the planet 66.043 million years ago which precisely marks the boundary of Cretaceous and Paleogene Periods. So even it was the combination of those two events, I would say it is the asteroid that broke the camel's back even if was the Deccan Traps would have finished the job.

[@thenerdbeast7375]

I always hated this statement as it is absolute hokum. Even if there was a drop in diversity in some parts of the world, it just signifies an ecological shift not that a group of animals is doomed. That is like saying because of the lack of megafauna diversity in North America today means "mammals are on their way out." In North America less dinosaur diversity was due to a multitude of factors; the decline of gymnosperms for the favor angiosperms likely caused a decline in many dinosaurs including sauropods but caused population booms in the herbivores that thrived on angiosperms, T.Rex's niche partitioning with its young caused a decline in medium tier predators and they continued to thrive on the angiosperm-loving prey they were suited to hunt. As time went on the fewer species in North America would likely have diversified into a multitude of species eventually due to competition but they never got the chance. I think the reason for this theory's popularity is actually humanity's hubris; we are looking for an excuse for the dinosaurs' extinction to "justify" a group of animals more successful than we'll ever be to go extinct that way we feel more significant and bolster our ego.

[@ayeehmanfeudo5749]

I really Love this kind of Channel.Thank you for sharing.❤

[@christiangalaz482]

Yeah, some populations of dinosaurs were having big enviromental troubles but not by any means dying, life and evolution have surpassed way worse obstacles.

[@johnwatsoniv384]

The most accurate interpretation would be that they were thriving and dominated the world until the asteroid. Mammals dominate the world today and clearly are thriving overall even though there are fewer species now than, say, 100,000 years ago. I certainly wouldn't say that mammals are on the way out, it's just that humans, wolves, and big cats dominate 90% of the planet and humans especially don't leave any room for other species to rise to the top. I would also suspect that there were a lot of smaller dinosaurs during that period that never fossilized or that we haven't found yet. Just as in mammals, it's clear that the largest herbivores from the Jurassic were being replaced by smaller, more armored herbivores like triceratops in the Cretaceous, while the carnivores were starting to level off in size. Mammals have done the same thing on a shorter time scale (and smaller size scale), such that now most herbivores are medium sized (deer, moose, zebras, antelope, buffalo, etc) and we have only a few large ones (elephants, rhinos, giraffes) in addition to carnivores getting smaller. I certainly don't think you can make a case that mammals are in danger of being overtaken by any other group, it's just that a few species have developed to dominate. I would argue the dinosaurs were in a stronger position than mammals are today due to the fact that there are some niches and circumstances where reptiles and birds remain the top species, whereas during the dinosaurs every landmass and biological role was dominated by the dinosaurs, and the skies were dominated by flying reptiles.

[@badshibari6707]

(Serious question) if an environment is stable and you have 10s of millions of years to perfect your adaption to your niche, is it not likely you would eventually land on speciation stagnation? We see huge bursts of diversity after mass extinctions because there is a vacuum created. So couldn't it work in reverse?

[@Dr.Ian-Plect]

Relative stagnation, yes. But evolution is never-ending. In an unchanging environment there are still a multitude of phenotypic variations that will fit well enough to thrive.

[@ApartmentPrepping]

The asteroid probably just destroyed the recent fossils resulting in apparent diversity loss

[@pluckyoompa3028]

I never thought about this before.

[@Djuuugarn]

Well the closer you get to the extinction event the less fossils there are…. This is not odd at all. The violent extinction event destroyed bones and fossils in the upper layers of the earth. How does no one see this???

[@killgazmotron]

A lack of species would be correlative but not a certainty of decline. You could be losing species because you are dying out, but you could also be losing species because every niche filled is so well evolved that they just out class every other like animal close to their niche. The last ages of the dinosaurs could have just been the point in time where there was just so many individuals so good at what they do that specialists were just never going to happen. every species was just carrying the most perfect tool box for their environment that had ever evolved up to that point.

[@Pipkiablo]

I don't believe the non-avian dinosaurs would have gone extinct if it weren't for the asteroid. They would have dipped, but unless the cause of their loss in diversity worsened, they probably would have come back from it eventually. It might have taken a few million years to regain diversity, but whatever caused the decline was definitely not on scale with the Permian extinction, so they probably would have pulled through in time.

[@AtillaTheFun1337]

Could it also just be that Cretaceous conditions were less conductive to fossilization? I mean to put things into perspective, we only know 700sh confirmed dinosaurs across the entirety of the many millions of years of the Mesozoic, yet we know of roughly 45,000 species of vertebrates currently alive. With numbers like this, our view of prehistoric times is always going to be spotty at best. There could be entire clades that simply never fossilized

[@user-rd8vp6nq8b]

It turns out that nobody will ever know because nobody lived back then

[@williamsparks1521]

Actually there is such a small sampling of fossils that this assessment is unlikely.

[@nimomemre6550]

The conclusion (I think) is that dinosaurs because of the lack of diversity would have gone extinct in a long run (or at least would've lost their dominant status) but the asteroid made a short work out of them.

[@furioussherman7265]

I remember reading a National Geographic article from the 2000s that mentioned this and, based on what I remember, it seemed as though the dinosaurs were on the verge of entering into a new period when the asteroid hit.

[@nicelydunwell5681]

New research shows they were becoming increasingly divided along ideological, political and religious grounds

[@5ives_the_penguin]

Hey I love ur vids could u do one for Zuchengtyrannus if I have the time?

[@octopustigerfish778]

Many other animals other than non avian dinos went extinct though. You had almost all bird lineages, pterosaurs, most marine reptiles, most turtles, most crocodiles, ammonites, many cephalopod lineages, crustaceans and even a lot of mammals. Marsupials we’re almost completely wiped out in the norther hemisphere. These animals should of all been experiencing a decline. Non avian Dino’s were not even really experiencing a decline over all. We have just been looking at one locality in one continent in one habitat. They were doing fine almost everywhere else. The non avian dinosaurs going extinct is the equivalent to all mammals dying out. That requires a major extinction

[@iiiiiiiiiiiiiiiivy]

It's plausible that as time went on, various dinosaur species may have become more and more specialized. What I mean is that other species would have found it increasingly more difficult to compete and exist alongside the more specialized ones. This could have caused the number of total species to decline, however, the survivors would have been very successful (and thus numerous). The problem they faced with the asteroid was that they as specialists were poorly equipped to survive such a dramatic change in their environment, and since the diversity of dinosaurs would have been lower and the species mostly specialist in nature, they as a whole were unable to survive the K-Pg extinction. (I'm not a paleontologist or biologist, so I will acknowledge that my reasoning here could be flawed.)

[@thongorshengar]

Ornithiscian would've been still the big herbivore around for sure. They were thriving because they adapted to eating angiosperm foliage and the further proliferation of it should make them even more diverse. Compared to declining titanosaur because their preferred ultra tall gymnosperm tree getting replaced as time goes on.

[@Trollonarolllol]

At 2:27 can somebody tell men where this clip is from

[@ExtinctZoo]

Jurassic fight club

[@Trollonarolllol]

@@ExtinctZoo do you know what episode

[@Rune_Scholar]

Eh....dude, dinosaurs DID continue thriving and dominating the world. They are currently present on every continent, including Antarctica, something that not all current groups can claim.

[@ExtinctZoo]

I said non avian at the start, I do not repeat it every time because it can get repetitive.

[@Rune_Scholar]

@@ExtinctZoo I know. I wasn't saying this to be antagonistic, just to underline how diverse they still are.

[@lifegettingintheway2710]

It is difficult for me to accept the asteroid notion for extinction given that Crocodilia are still with us with several verstions still living in the blast zone of the Chicxulub impact. Blaming DNA fatigue, climate, or prions seems as or more plausible.

[@billc.4584]

Didn't Bob Bakker posit like thirty years ago that, in his opinion, dinosaurs had been on the decline for at least ten million years prior to the asteroid impact? He suggested that the appearance of various land bridges allowed different ecological areas to interact along with their pathogens as dinosaurs migrated for which one group, or the other, had no coping mechanism. He further suggested that different environmental events (Deccan Traps etc.) were added stressors to various populations already in decline and noted the lessening of diversity as I recall. Peace.

[@Magneticlaw]

Number of species seems like a narrow way to define the 'success' of a species, seeing that there are plenty of species now with less representatives in diversity, but are hugely successful, namely humans, as well as raccoons, corvids, canines, cats, etc. 🐱

[@therizinosaurus193]

Wonder why North America had the most ceratopsians out of all the continents

[@GalvyTheTom]

Probably because they weren't able to cross continents as easily as other large dinosaurs like the large theropods and hadrosaurs. That, and most ceratopsid species of the Campanian seem to have been restricted to small ranges, perhaps because they kept evolving specialized appearances to differentiate themselves.

[@nicholasmaude6906]

While the Deccan traps flood-basalt eruptions had the non-avian dinosaurs on the ropes it was the Chixulub asteroid that finished them off.

[@loganw1232]

Walking with Dinosaurs had this theory in 1999

[@varanid9]

They "started dying" 40 to 50 MILLION YEARS before they died out?? LOL! Aren't we all?

[@blackestyang7528]

I think the folks claiming they were on the decline forgot the difference between background extinction and mass extinction

[@kennethsatria6607]

Low in diversity doesn't sound like much when you consider the dinosaurs probably out competed others of the same kind of niche, like there used to be loads of different predatory animals after the dinosaurs that hunted by pursuit, like entelodonts, land running crocs or terror birds, but a matter of efficiency, competiton and other natural changes in the environment made the selection steeper until we're left with dogs and cats as dominant running predators. It probably didn't help their kind as a whole to survive the mass extinction when everyone was becoming that specialized as animals, but it sounds like if the comet didn't hit dinosaurs would still rule, they'd just be a lot more bland in variety of animals before something could force them out of that kind of stagnation like a less severe mass extinction.

[@neonity4294]

To be more specific: It's an "possible" answer for the good old question of how and why the dinosaurs could go extinct within years after the impact. So far not an single extinction event was able to eliminate an whole clade of animals, some species were always able to survive or even recover. It got a bit more complicated with the discovery of arctic dinosaurs, before everyone was sure they could only survive within a relatively moderate to tropical climate zone.

[@globin3477]

I don't think that's right... First of all, Three groups of dinosaurs DID survive the impact: Fowl, Ratites, and Neoavians. Second, I'm pretty sure that the Great Dying wiped out at least a few clades. Also, "Clade" Is a fairly broad term that can apply to groups of vastly different ages and sizes. Hummingbirds are a clade, birds as a whole are a clade, dinosaurs (including birds) are a clade, e.t.c.

[@-TheUnkownUser]

probably yes the were struggling because of the planet changing and all that, but i don't think that it was so harmful to the point of going extinct...

[@yodasmomisondrugs7959]

Just like the Bronze Age Collapse its never just one thing that brings and end to a system.

[@mistyhaney5565]

If you base thriving on number of species, humans are in trouble.

[@jhardy133]

If the Alvarez bolide killed any dinos where are the fossils mixed in with the KT boundary? There have been some redeposited dino fossils at or very near the boundary, (both above and below it), but, no vast bonebeds found around the world. Geologic time can be misunderstood very easily. The idea that because the dino fossils are found below the boundary does not necessarily imply that the extinction event was linked to the bolide collision. The global poisoning of the atmosphere by the Deccan Traps lasted for thousands of years and was most likely the main cause of the decline in species diversity. Some species seem to have been less affected, however, and were thriving before the toxicity simply overwhelmed them. The last non-avian dinosaur died thousands of years before the planet was struck by the asteroid/comet.

[@GalvyTheTom]

You have to understand, fossilization is extremely rare. The fact that we can track their fossil record as well as we can up to the end of the Cretaceous is impressive, and with how their disappearance coincides with the K-Pg boundary, that's the best bet we have. And even then, we have evidence of a burnt Thescelosaurus leg in the same line as the boundary along with fossils of aquatic animals seemingly killed in a series of events that coincides too well with an asteroid impact.

[@GalvyTheTom]

Also, wouldn't marine animals be visibly affected by the Deccan Traps if they were the driving cause of the extinction? Heavy volcanic activity is connected to marine extinctions at the end of the Permian, but animals like ammonites hung on at least to the Paleocene or beyond, with large marine reptiles dying out at the same time as the non-avian dinosaurs; if volcanism was the main factor, they'd have a more explicit decline.

[@TenorCantusFirmus]

Maybe, Dinosaurs were going throught a phisiological Bottleneck, with the most specialized and better-fit species for a given niche establishing its or their dominance and driving the others to extinction throught Natural Selection, when the asteroid arrived in the worst and most delicate possible moments, the middle of the Bottleneck. Might be, without the asteroid, we would have seen a new radiation cycle starting from the relatively few species remained.

[@benwest9004]

It really has to do with evolutionary flexibility of the existing species. If they can adapt to future changes in their environments. Basically regardless of the amount of species or even the number of individuals if they were thriving at the moment is meaningless if they all die during the first ice age. A good example would be grey wolves and Marsupials. Wolves, a single species, live in many different environments today and have the genetic potential to evolve into many new species. Marsupials an entire diverse group of mammals can be thriving in both senses of the term but almost completely lack the ability to compete with placental mammals on an evolutionary scale.

[@trvth1s]

I wouldn't say marsupials can't compete with mammals. Opossums are thriving. Unfortunately for marsupials, after the kt extinction they dominated south America, Antarctica and Australia. Antarctica terrestrial fauna all died during the ice cap formation with only a few species of dinosaurs surviving (penguins) while Australia and South America drifted away becoming isolated. India was also isolated and dominated by marsupials until they ran unto Eurasia. Placentals dominated n America, Eurasia and Africa which connected thus placentals faced more competition becoming more specialized. Canids are an example. They began in n America but competed with carnivores in Eurasia and Africa filling niches in each continent. By the time humans brought dingoes to Australia, the Australian marsupials like thylacine couldn't compete. Though convergence evolution made their bones very similar to canids, canids were far more competitive in things bones don't show you like pack hunting. FYI ice age would not have killed off dinosaurs. Dinosaurs lived in Antarctica and still do. Today's dinosaurs live in cold environments no mammal could survive. Their metabolic rate is above mammals thus why they were more upright and more active

[@benwest9004]

@@trvth1s About the ice age. I was referring to the existent species of dinos 65 million years ago. The amount of them or the number of species at that time means little 65 million years and massive changes in the climate later. As for Opossums. I have a lot of first hand experience with them (the north American ones anyway). They have no future in evolution. Raccoons or even rats would eventually force them into extinction given enough time. They simply do not have the genetic or behavioral flexibility to evolve fast enough.

[@trvth1s]

@@benwest9004 if nonavian dinosaurs would have survived the kt extinction, they would have diversified and spread relatively quickly like they did after the triassic extinction which BTW was worse than the kt extinction. As for opossums, their gestation period is 13 days, what do you mean they can't evolve fast enough? 13 day gestation period means they can evolve faster than almost any vertebrate. This is why they're so successful.

[@benwest9004]

@@trvth1s Yet no nonavian dinosaurs survived the KT extinction. Mammals, birds, lizards and crocodiles all survived. For some reason not a single nonavian dinosaur of any size had the ability to survive the KT extinction. Could this same reason cause them to go extinct later on under different circumstances? A chicken can lay an egg every day but it takes longer than a day to hatch. 13 days is not the total time from conception to climbing out of the pouch. They are also extremely short lived. Living only 3 years at most. Evolution is not 100% about birth rate anyway. If you were correct we would have more than a single species in North America. Look at all the canid species in South America that emerged in the same timeframe. That is a high rate of evolution. North American Opossum success has to do with them being a generalist. That might get them a few million years but in the long run they will be displaced.

[@trvth1s]

@@benwest9004 birds (dinosaurs) occupied the niche of small generalist in the late cretaceous. Non avian dinosaurs (and pterosaurs) were bigger than ever during the late cretaceous. We didn't have all of the small generalist non avian dinosaurs and pterosaurs that we had during the triassic. Now we have more bird species than mammals. Evolution happens with tine when niches open. S. America, being Isolated, was at a disadvantage with North America fauna and we saw the results but that was only 3 million years ago. I expect the same to happen when Australia slams into Asia.

[@eamonahern7495]

Plot twist. One particular dinosaur developed advanced technology that integrated so well with nature that we cannot detect it today. They dominated the earth as homosapiens do today and developed advanced weapons. It wasn't an asteroid but a massive nuclear weapon fired from one part of the earth to space, re-entering the atmosphere during a devastating world war.

[@philipnorris6542]

We can't know all the finer points.

[@trvth1s]

They always make these predictions when they lack fossils. They said the same about pterosaurs until finding a massive fossil bed in Greek Islands with a plethora of pterosaur species from the late cretaceous.

[@jourdansarpy4935]

What’s frustrating to me is that birds literally are dinosaurs and they are still thriving. Maybe ancient body types were declining, but there are still more species of birds than mammals right now.

[@trvth1s]

Ancient body types? Mammals and birds are older than most nonavian dinosaurs. Tyranosaurids, ankylosaurids, ceratopcians etc all evolved tens of millions of years AFTER mammals and birds

[@jourdansarpy4935]

@@trvth1s non avian dinosaurs evolved well before dinosaurs evolved into birds and true mammals existed. Please don’t make stuff up in my comments.

[@trvth1s]

@@jourdansarpy4935 you must have poor reading comprehension. The key word is MOST. Birds and mammals evolved about 150 million years ago. Tyranosaurids, ankylosaurids, ceratopcians, dromeosaurids and most other dinosaurs evolved tens of millions of years AFTER that. That's something most people don't realize; birds were 1 of the first dinosaurs to evolve and mammals are as old as them. Also, basal mammals ruled the earth long before dinosaurs existed during the Permian. Saber tooths like the furry gorgonopsids ruled earth before dinosaurs existed

[@jourdansarpy4935]

@@trvth1s you are naming a small number of the total Dinosaurs. The first ones evolved almost 200 million years ago. You’re trying to be semantic to prove a point but it’s all wrong.

[@trvth1s]

@@jourdansarpy4935 the first ones actually evolved several tens of millions of years earlier than you suggested, they evolved during the triassic but dinosaurs were by no means the dominant life form during the triassic, they weren't that diverse yet.

[@theblatantaussie1530]

I personally think that this hypothesis is just fashionable contrarianism. A way of demystifying dinosaurs, taking away a somewhat tragic character to their end. The theories also seem to just be fads that reflect what the state of mind humanity is in. Right now it is fashionable to believe that everything is climate related and can only be avoided by shaping nature, rather than adapting to it. Thus dinosaurs were doomed, because unlike us, they could not introduce snazzy policies to change the climate in their favour. I'd pay little attention to it.

[@pardefarmeaurx3720]

There are only 1 species of human, and there are 7 billion of us.....

[@nightraven2975]

We are.... a unique example.

[@Steven_Ray_Photography]

Correct me if I'm wrong but isn't fossilisation quite a rare occurrence? How is one supposed to study an entire population by only examining 5% of it?

[@emilebichelberger7590]

So what should we do instead?

[@firstcynic92]

Dinosaurs didn't go extinct.

[@TheFoshaMan]

non avian did

[@lokitus]

I guess primates are on their way out...

[@robotaholic]

My mama says god threw it at earth to make way for us. Lol I'm like couldn't god just think it and make them vanish? It's god were talking about lol. This is one of the zillion reasons why I'm an atheist

[@VGEmblem]

Maybe it'd make more sense to leave the evidence. Maybe god would rather follow the rules of his universe or do something more interesting. Who knows

[@omegaz3393]

Dinosaurs went extinct when homosapiens arrived on the seen. At first when confronted by the T-rex, homosapiens were terrified and ran screaming for caves. Having come upon a T-rex that got to close to a hot springs and inadvertently being cooked, it was learned that they tasted like chicken.😉 And the extinction began. 🤣😂

[@biguzivertt]

i feel like this whole “lack of diversity” argument fails when considering in the US they had TREX, a bigger and more successful hunter than any other theropod in the area. they probably dominated all the competition

[@SepiaChild]

Only God knows

[@Dr.Ian-Plect]

Demonstrate this 'god' exists, then demonstrate it knows.

[@curiousuranus810]

Why are you even reporting this debunked nonsense?

[@buttdickenz]

I just dont buy this this thing about not having many different species of dinosaur being a big cause. Really all you need for a reemergence of dinosaurs are a few good species. Personally I'd say it's normal for the amount of species to decline over time as over time everyone starts to specialize and the generalists will start having trouble competing as there is always someone that does it better.

[@aan2960]

Dinos were actually dead ends in bird evolution. Thatz it.

[@JohnSmith-xl9bo]

Botulism