Dinosaurs went extinct in a few hours

[Neosodon]

https://www.facebook.com/naturalhistorymuseumofutah/videos/1450573701646920/ at about 6 minutes in.

I new that the meteor impact would have put off allot of heat but this is the first I have heard anyone propose it happened on a global scale. I have always felt confident about the starvation theory but this seems like it could be plausible.

[stargatedalek]

Absolutely silly. If that were the case little more than microorganisms would have realistically survived.

[Reptilia]

Fascinating somehow, but the idea sounds more fitting for a sci-fi movie plot.

[Neosodon]

"Pizza Oven" temperature is a bit far fetched. But a few minutes of 150 - 200 degrees Fahrenheit temperature would have been enough to give any exposed animals heat strokes.

[Faelrin]

If it was that bad, wouldn't the rate of extinction be worse then the Permian-Triassic extinction?

[amargasaurus cazaui]

There is also a serious issue with the "lag" zone....the evidence does not seem to match this scenario ...only one (1) triceratops horn has ever been found  even close to the iridium layer....

[Blade-of-the-Moon]

eh..I don't buy it.  Sure the animal's nearest the point of impact would have and to various degrees out from it.  But extinction takes time...this sounds like a  media hype thing trying to put out something interesting or rehash it.

[Soopairik]

I doubt this happened, otherwise all other animals would've died too.

[Papi-Anon]

I've always been under the impression for years that the kicked-up carbon bonding with the atmospheric oxygen was one of the major reasons why the archosaur megafauna died out: that decreases in oxygen-content per breath paired with the non-avian dinosaurs having respiratory systems made for more oxygen-rich air did them in along with the breakdown of photosynthesis screwing up the food web.

[CityRaptor]

Uh, actually bird-like lungs are actually found in Theropods and Sauropodomorphs. And oxygen was actually lower several times during the Mesozoic.

[stargatedalek]

I've always been under the impression for years that the kicked-up carbon bonding with the atmospheric oxygen was one of the major reasons why the archosaur megafauna died out: that decreases in oxygen-content per breath paired with the non-avian dinosaurs having respiratory systems made for more oxygen-rich air did them in along with the breakdown of photosynthesis screwing up the food web.

If the air chemistry changes were really that profound I'd expect to notice the die-off most strongly among fish, at least freshwater varieties. Instead it's more or less the opposite, wherein a lot of different groups of fish survived the event.

[Papi-Anon]

Uh, actually bird-like lungs are actually found in Theropods and Sauropodomorphs. And oxygen was actually lower several times during the Mesozoic.

Well, learned something new. Still don't buy into the oven-temp theory entirely.

[Simon]

The size of the dinosaurs, combined with their warm-blooded energy (food) requirements, always suggested what this hypothesis provides further indication of - massive, catastrophic, sudden extinction.

Changes in environmental factors are things that dinosaurs - and animals before and after the Mesozoic - have always managed to adapt to, some more than others, depending on location and evolutionary adaptations that suddenly become fortuitous.

What is much, much harder - or impossible, to overcome - is a complete, sudden, world-wide catastrophe.  And that is exactly the scenario that was served up by the Chixculub asteroid strike.  A rain of suffocating fire and boiling temperatures, followed by acid rain and a several-year long "hard freeze".

Animals capable of burrowing and hibernating (birds, snakes, crocs, small mammals, etc) were able to survive.  But those strategies were not available to the animals that dominated the food chain, because their lifestyle/size/warm blooded body design did not require it - prior to the asteroid strike.

This analysis is the only one that made complete sense ever since Alvarez announced the discovery of the Iridium layer, because anything less than an apocalyptic scenario would not have resulted in the kind of complete die-off of any terrestrial animal larger than a cat virtually instantaneously, as the geologic record indicates.

Really, the only issues in this debate for the past 36 years have had to do with piecing together the physical scenario of the immediate results of the asteroid strike.  The global-conflagration was known from soot deposits as far back as the 1980s (when I recall first reading about them).  More sophisticated analyses since then have only added to the cataclysmic scenario of horrors that were the immediate result of the asteroid impact.

[ZoPteryx]

I agree with the general sentiment this extremely rapid scenario is probably too extreme, at least globally.

There is also a serious issue with the "lag" zone....the evidence does not seem to match this scenario ...only one (1) triceratops horn has ever been found  even close to the iridium layer....

There is also an undescribed mostly articulated ornithomimid from "the gap".

[amargasaurus cazaui]

I agree with the general sentiment this extremely rapid scenario is probably too extreme, at least globally.

There is also a serious issue with the "lag" zone....the evidence does not seem to match this scenario ...only one (1) triceratops horn has ever been found  even close to the iridium layer....

There is also an undescribed mostly articulated ornithomimid from "the gap".

without knowing the particular specimen or it circumstances, I would be quite ....skeptical of what layer or how it was found until it has been described and is determined as not having been reworked or in some way shuffled within the geological context. There was an entire pocket of dinosaur fossils described as being above the iridium layer at one point until it ws found the entire strata had been reworked ...in essence a tectonic type event shuffled the layers.
   Those most fond of the impact event and its supposed "fire and brimstone" death scenario ignore various pieces of evidence like the gap....and that the evidence suggest a rain of mud and water rather than fire and ash. Aside from this, if the dinosaurs had all died within a few hours we would find a layer heavily choked with dead fauna and biomass, which is to date not known as existent. Aside from the obvious question..if you incinerate and eliminate nearly all plant and surface fauna, just how was anything supposed to breathe? Their are serious issues and always have been with a single impact, rapid decimation answer.