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Drought Reveals Rare American Lion Fossil in Dried Up Mississippi River

smithsonianmag.com

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Re: Drought Reveals Rare American Lion Fossil in Dried Up Mississippi River

#11

Post by adastra22 »

MichaelCollins wrote: post #10
xyzzyz wrote: post #7

Earlier quoted context omitted.

Ice age was not that much colder than now. Most of Canada was covered with ice, but most of United States wasn’t. Places which are hot today were warm at the time, and places that are warm were temperate. This means that there is no reason to assume that food was scarce. Here is a way to think about it: Alaska today is probably colder than southeastern US was during ice age. Is food in Alaska so scarce today that it…

I feel like you're understating it a bit; 20k years ago Manhattan was covered in over a thousand feet of ice. The Wisconsin Ice Sheet was huge and covered a substantial portion of the modern day United States: https://en.wikipedia.org/wiki/Wisconsin_glaciation#/media/Fi...

Correct, but this is more about the slow accumulation of snow, not all of which melts during summer. Over thousands of years, this leads to thousands of feet of packed snow.

Re: Drought Reveals Rare American Lion Fossil in Dried Up Mississippi River

#12

Post by TomK32 »

MichaelCollins wrote: post #10
xyzzyz wrote: post #7

Earlier quoted context omitted.

Ice age was not that much colder than now. Most of Canada was covered with ice, but most of United States wasn’t. Places which are hot today were warm at the time, and places that are warm were temperate. This means that there is no reason to assume that food was scarce. Here is a way to think about it: Alaska today is probably colder than southeastern US was during ice age. Is food in Alaska so scarce today that it…

I feel like you're understating it a bit; 20k years ago Manhattan was covered in over a thousand feet of ice. The Wisconsin Ice Sheet was huge and covered a substantial portion of the modern day United States: https://en.wikipedia.org/wiki/Wisconsin_glaciation#/media/Fi...

The Mississippi must have been gigantic in summers when some of the glacier ice did melt.

Re: Drought Reveals Rare American Lion Fossil in Dried Up Mississippi River

#13

Post by thaumasiotes »

TomK32 wrote: post #12
MichaelCollins wrote: post #10

Earlier quoted context omitted.

I feel like you're understating it a bit; 20k years ago Manhattan was covered in over a thousand feet of ice. The Wisconsin Ice Sheet was huge and covered a substantial portion of the modern day United States: https://en.wikipedia.org/wiki/Wisconsin_glaciation#/media/Fi...

The Mississippi must have been gigantic in summers when some of the glacier ice did melt.

The size of the river is related to the amount of ice that melts.

But the amount of ice that melts is completely unrelated to the amount of ice contained in the glacier.

Re: Drought Reveals Rare American Lion Fossil in Dried Up Mississippi River

#14

Post by EdwardDiego »

chrisco255 wrote: post #2

I'm always amazed when reading about the sheer size of ice age animals that existed. I kinda get how dinosaurs were able to get so large, due to environmental factors at the time, but you would assume that food was sparse during the ice age. How did the ecosystem support large mammals?

Larger animals retain heat better. The square-cube law in action. Hence why dragonflies in the lowlands of my country are quite small, but the ones in sub-alpine regions are fricking massive. (Ditto the hares).

https://en.wikipedia.org/wiki/Square–cube_law

Re: Drought Reveals Rare American Lion Fossil in Dried Up Mississippi River

#15

Post by EdwardDiego »

pazimzadeh wrote: post #8
chrisco255 wrote: post #2

I'm always amazed when reading about the sheer size of ice age animals that existed. I kinda get how dinosaurs were able to get so large, due to environmental factors at the time, but you would assume that food was sparse during the ice age. How did the ecosystem support large mammals?

Maybe slower metabolism/heartbeat since they retain heat better Also, is it a coincidence that tech gets smaller over time? Maybe there is a shared reason why larger systems are easier to implement, at first

Square-cube law - larger animals retain heat better.

Re: Drought Reveals Rare American Lion Fossil in Dried Up Mississippi River

#16

Post by Xixi »

MichaelCollins wrote: post #10
xyzzyz wrote: post #7

Earlier quoted context omitted.

Ice age was not that much colder than now. Most of Canada was covered with ice, but most of United States wasn’t. Places which are hot today were warm at the time, and places that are warm were temperate. This means that there is no reason to assume that food was scarce. Here is a way to think about it: Alaska today is probably colder than southeastern US was during ice age. Is food in Alaska so scarce today that it…

I feel like you're understating it a bit; 20k years ago Manhattan was covered in over a thousand feet of ice. The Wisconsin Ice Sheet was huge and covered a substantial portion of the modern day United States: https://en.wikipedia.org/wiki/Wisconsin_glaciation#/media/Fi...

On the other hand, the planet was only 4~4.5ºC cooler than at the beginning of the industrial area, so it was not that much cooler. For those who think that warming up the planet by 3 or 4ºC is not a big deal...

Re: Drought Reveals Rare American Lion Fossil in Dried Up Mississippi River

#17

Post by guelo »

mlindner wrote: post #3

Unfortunate they don't seem to have any pictures in the article of this animal. Just a top level image showing some barges on the river. Anyone have an alternate link that shows images?

It's just a tooth but it's pretty cool https://www.sunherald.com/news/state/mississippi/article2682...

Re: Drought Reveals Rare American Lion Fossil in Dried Up Mississippi River

#18

Post by DrBazza »

chrisco255 wrote: post #2

I'm always amazed when reading about the sheer size of ice age animals that existed. I kinda get how dinosaurs were able to get so large, due to environmental factors at the time, but you would assume that food was sparse during the ice age. How did the ecosystem support large mammals?

Glyptodons in South America made huge burrows:

https://www.discovermagazine.com/planet-earth/get-lost-in-me...

Then consider that plants have a symbiotic relationship with animals.

And think about the size of Avocados (for example), and in particular the seed in the middle. Birds aren't going to distribute them...

Re: Drought Reveals Rare American Lion Fossil in Dried Up Mississippi River

#19

Post by greggsy »

DrBazza wrote: post #18
chrisco255 wrote: post #2

I'm always amazed when reading about the sheer size of ice age animals that existed. I kinda get how dinosaurs were able to get so large, due to environmental factors at the time, but you would assume that food was sparse during the ice age. How did the ecosystem support large mammals?

Glyptodons in South America made huge burrows: https://www.discovermagazine.com/planet-earth/get-lost-in-me... Then consider that plants have a symbiotic relationship with animals. And think about the size of Avocados (for example), and in particular the seed in the middle. Birds aren't going to distribute them...

I’ve read that sloths we’re responsible for spreading avocado seeds, but it makes me wonder whether those seeds were always that large?

Re: Drought Reveals Rare American Lion Fossil in Dried Up Mississippi River

#20

Post by Mistletoe »

Decabytes wrote: post #5
chrisco255 wrote: post #2

I'm always amazed when reading about the sheer size of ice age animals that existed. I kinda get how dinosaurs were able to get so large, due to environmental factors at the time, but you would assume that food was sparse during the ice age. How did the ecosystem support large mammals?

Megafauna were actually the norm. Just look at the Dinosaurs and Mammoths. So being smaller is a recent change. Larger animals are more efficient with their calories, expending less energy per pound vs a smaller animal. Large animals also have a better volume to surface ratio, making it easier for them to keep themselves warm.

>Larger animals are more efficient with their calories, expending less energy per pound vs a smaller animal.

Interesting. If this is true, why do feed efficiency graphs look like this?

https://ib.bioninja.com.au/options/option-c-ecology-and-cons...

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