Earlier quoted context omitted.
The Northern Hemisphere does account for 68% of overall land area. https://www.worldatlas.com/articles/which-hemisphere-has-the...
Did it at the K-T boundary?
Yes.
An asteroid killed dinosaurs in spring, which might explain why mammals survived
61–70 of 87 posts
Re: An asteroid killed dinosaurs in spring, which might explain why mammals survived
#62Earlier quoted context omitted.
The cretaceous atmosphere had a higher oxygen concentration (roughly 50% more oxygen than today). It was denser, but the idea that it provided structural support for large animals is ridiculous. Part of the reason animals could be larger then (from "giant" insects to genuinely-giant dinosaurs) is that the extra oxygen meant smaller lungs (or better absorption for non-lung-havers) required to support higher energy use…
Pressurized gas can act like a liquid. And at sea level, thick atmosphere would certainly be pressurized. smaller lungs aren't relevant to the issue that comes up regarding extremely large dinosaurs. Because it's not an issue of lung capacity, or oxygen supply per liter of blood. We're not talking about animals that are comparable to modern day elephants. Have you seen the size comparisons of dreadnoughtus to blue wh…
Bible scholars generally favor the idea that the expanse mentioned in Genesis - a heavy atmosphere of water vapor that is said to have given the entire earth a tropical climate - could have had a significant effect on atmospheric density, which I personally find an interesting correlation when discussing this topic.
Combined with the snap frozen mammoth hypothesis, it's interesting to think that if there were a heavy atmosphere of liquid, and it suddenly fell, it could explain why dinosaurs are non-feasible in todays atmosphere, why a sudden change in atmospheric density could be possible, the paradox of a whole-earth tropic, the snap frozen mammoths, and also the sudden extinction of large land animals such as dinosaurs.
(Anecdotally, a question I wonder: is it feasible that humans would live longer in higher pressures and lower UV levels, such as to 900 years?)
Re: An asteroid killed dinosaurs in spring, which might explain why mammals survived
#63Spring in the Northern Hemisphere; Fall in the Southern Hemisphere.
Fall in the Southern Hemisphere.
FYI we call it autumn.
Re: An asteroid killed dinosaurs in spring, which might explain why mammals survived
#64One thing that isn't talked about as much as it should be, there's a possibility that 65 million years ago during the time of the dinosaurs, the earth's atmosphere was very thick. All these Dinosaurs with their extremely long necks and bodies couldn't support their own weight if wandering around the earth today. The mass extinction event may have occurred simply because the atmosphere changed and these giant beasts u…
This is completely absurd. The density of air is about 1/1000th the density of body tissue. The effect you are talking about there is negligible, and would remain so even if the atmosphere doubled in mass (hell, if it increased by a factor of 10).
Re: An asteroid killed dinosaurs in spring, which might explain why mammals survived
#65Only half of the Earth would be destroyed in that manner due to Earth Northern hemisphere and Southern hemisphere having opposite seasons. Go back to the drawing board.
Read the article. That's their point: it was fall on the opposite hemisphere where mammals were sheltering and preparing for winter.
Re: An asteroid killed dinosaurs in spring, which might explain why mammals survived
#66Re: An asteroid killed dinosaurs in spring, which might explain why mammals survived
#67Earlier quoted context omitted.
If we wipe ourselves out within 100,000 years, I'm not sure "intelligence" is a particularly advantageous trait, evolutionarily-speaking.
For long term survival you need to get off your planet, for which you probably need intelligence. Earth has around half a billion years left until it starts feeling serious issues with our sun. If our evolution took something like 10 percent longer things would be tricky
Or become a bacteria that has a really great chance at surviving in space and have your planet get hit by an asteroid. You go up in debris and colonize the galaxy over millions of years
Re: An asteroid killed dinosaurs in spring, which might explain why mammals survived
#68> Three-dimensional rendering of the partial paddlefish fossil, with googly eyes added for reference . I'm glad to see even serious scientists can have fun sometimes.
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Re: An asteroid killed dinosaurs in spring, which might explain why mammals survived
#69> Three-dimensional rendering of the partial paddlefish fossil, with googly eyes added for reference . I'm glad to see even serious scientists can have fun sometimes.
The author’s “brand” seems to be dayglo pink hair.
Scientists, these days, can sport a different attitude, compared to the horn-rimmed-glasses-and-elbow-patched-tweed of the stereotypical “scientist,” of popular culture.
I always get a kick out of the mission control videos.
Re: An asteroid killed dinosaurs in spring, which might explain why mammals survived
#70Earlier quoted context omitted.
The cretaceous atmosphere had a higher oxygen concentration (roughly 50% more oxygen than today). It was denser, but the idea that it provided structural support for large animals is ridiculous. Part of the reason animals could be larger then (from "giant" insects to genuinely-giant dinosaurs) is that the extra oxygen meant smaller lungs (or better absorption for non-lung-havers) required to support higher energy use…
Pressurized gas can act like a liquid. And at sea level, thick atmosphere would certainly be pressurized. smaller lungs aren't relevant to the issue that comes up regarding extremely large dinosaurs. Because it's not an issue of lung capacity, or oxygen supply per liter of blood. We're not talking about animals that are comparable to modern day elephants. Have you seen the size comparisons of dreadnoughtus to blue wh…
> Like a whale plopped on dry land, they'd collapse under their own weight standing up. Much less, hunting, mating, and fighting.
Just to be clear, you're talking about the buoyancy effect that a denser atmosphere provides to land animals?