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Drought Reveals Rare American Lion Fossil in Dried Up Mississippi River

75 points by akeck 4y ago

chrisco255 4y ago
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?
- Decabytes 4y ago
  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.
  - Mistletoe 4y ago
    >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-conser/c2-communities-and-ecosyste/feed-conversion-ratio.html https://ib.bioninja.com.au/options/option-c-ecology-and-cons...
    - Enginerrrd 4y ago
      That's a pretty unfair comparison. Cows eat grass. Pigs and chickens are omnivores that can save themselves from the synthesis of a lot of protein building blocks. Fish are cold blooded so they don't waste a big portion of calories that they eat keeping warm. Only the comparison between chickens and pigs is really relevant here.
- tastyfreeze 4y ago
  Cold favors a large body with a higher mass to surface area. But an ice age isn't all ice, snow and eternal winter. There were still seasons south of the ice sheets where the animals lived.
- xyzzyz 4y ago
  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 does not support megafauna? Obviously it’s not, quite the opposite. Same was true about most of US during last ice age.
  - dataflow 4y ago
    > Obviously it’s not To be honest I don't think that's obvious to people who don't know much about Alaska.
  - MichaelCollins 4y ago
    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/File:Iceage_north-glacial_hg.png https://en.wikipedia.org/wiki/Wisconsin_glaciation#/media/Fi...
    - adastra22 4y ago
      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.
    - TomK32 4y ago
      The Mississippi must have been gigantic in summers when some of the glacier ice did melt.
      - thaumasiotes 4y ago
        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.
- pazimzadeh 4y ago
  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
  - EdwardDiego 4y ago
    Square-cube law - larger animals retain heat better.
- EdwardDiego 4y ago
  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 https://en.wikipedia.org/wiki/Square–cube_law
  - WallabyEV 4y ago
    Interesting note and a curious thing to apply in my local area. We have lots of cross breed lizards like horned toads and newts and anoles. We love their feeding habits. Compared to the rainforest lizards, our prairie ones are 4x larger on average. Like dwarf iguanas in some respects with large claws and speed. I’m also a huge fan of dragonflies here in north Texas - quite common seeing 3-5” long ones zooming about with gorgeous variety of colors. I’ve noticed they appreciate outdoor fans and treat the breeze path as a playground.
  - chrisco255 4y ago
    The earth was much warmer during the era of dinosaurs, and yet they still grew to such sizes. I'm not sure that body heat retention is a great explanation, especially given the thick fur coats of most modern mammals that were evolved for the cold. I'm mostly curious how the ecosystem was able to support so many large animals, from the base layer of the food chain up. If there was an ice sheet a mile thick covering all of Canada down to Wisconsin, then most of north America must have been tundra. Were there less trees? Did grasslands thrive across the continent which supported ruminants more, which in turn provided more food for large predators?
    - EdwardDiego 4y ago
      Fair comment. :) I was referencing Bergmann's Rule [0], which really only applies to warm blooded animals but there's also a theory that evolving a larger size helps ectotherms maintain a stable temperature also. [1], and relating to your question on carrying capacity of the food available - the Jarman-Bell Principle [2] that larger herbivores can subsist better on low quality food than smaller herbivores. And, for interest, Allen's Rule on body appendages for temperature regulation. [3] There's also Cope's Rule - that animals just tend to evolve to get larger, until that's no longer viable. [4] I can't comment on how valid any of them are, as I'm just an armchair biologist :D [0]: https://en.wikipedia.org/wiki/Bergmann%27s_rule https://en.wikipedia.org/wiki/Bergmann%27s_rule [1]: https://en.wikipedia.org/wiki/Gigantothermy https://en.wikipedia.org/wiki/Gigantothermy [2]: https://en.wikipedia.org/wiki/Jarman-Bell_principle https://en.wikipedia.org/wiki/Jarman-Bell_principle [3]: https://en.wikipedia.org/wiki/Allen%27s_rule https://en.wikipedia.org/wiki/Allen%27s_rule [4]: https://en.wikipedia.org/wiki/Cope%27s_rule https://en.wikipedia.org/wiki/Cope%27s_rule
- DrBazza 4y ago
  Glyptodons in South America made huge burrows: https://www.discovermagazine.com/planet-earth/get-lost-in-mega-tunnels-dug-by-south-american-megafauna 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...
  - greggsy 4y ago
    I’ve read that sloths we’re responsible for spreading avocado seeds, but it makes me wonder whether those seeds were always that large?
    - DrBazza 4y ago
      Yes. I used avocados as an example because everyone is well aware how large the seed is. I couldn't find the original reference, but there's a few papers on how there are South American plants that now geographically isolated because there's no megafauna to eat and disperse the seeds.
  - brnt 4y ago
    I'm assuming any fruit or veg grown by humans are heavily tuned versions of some wild ancestor, and may seem to have little in common with it. How 'original' are the avocados we all know and love?
mlindner 4y ago
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?
- mc32 4y ago
  It’s not even the Mississippi River it’s a log chute arm of the river. If you look up top you can see where the arm ends.
- guelo 4y ago
  It's just a tooth but it's pretty cool https://www.sunherald.com/news/state/mississippi/article268277647.html?utm_source=pushly&intcid=pushly_2480125 https://www.sunherald.com/news/state/mississippi/article2682...
gpvos 4y ago
The American Lion: it's BIGGER than other lions!
shard 4y ago
In a similar vein, the drying of Lake Mead is revealing bodies of victims of accidents and foul play: https://www.thefocus.news/culture/why-is-lake-mead-drying-up-fourth-set-of-human-remains-discovered/ https://www.thefocus.news/culture/why-is-lake-mead-drying-up...

75 points by akeck 4y ago

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?

Decabytes 4y ago
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.
- Mistletoe 4y ago
  >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-conser/c2-communities-and-ecosyste/feed-conversion-ratio.html https://ib.bioninja.com.au/options/option-c-ecology-and-cons...
  - Enginerrrd 4y ago
    That's a pretty unfair comparison. Cows eat grass. Pigs and chickens are omnivores that can save themselves from the synthesis of a lot of protein building blocks. Fish are cold blooded so they don't waste a big portion of calories that they eat keeping warm. Only the comparison between chickens and pigs is really relevant here.
tastyfreeze 4y ago
Cold favors a large body with a higher mass to surface area. But an ice age isn't all ice, snow and eternal winter. There were still seasons south of the ice sheets where the animals lived.
xyzzyz 4y ago
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 does not support megafauna? Obviously it’s not, quite the opposite. Same was true about most of US during last ice age.
- dataflow 4y ago
  > Obviously it’s not To be honest I don't think that's obvious to people who don't know much about Alaska.
- MichaelCollins 4y ago
  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/File:Iceage_north-glacial_hg.png https://en.wikipedia.org/wiki/Wisconsin_glaciation#/media/Fi...
  - adastra22 4y ago
    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.
  - TomK32 4y ago
    The Mississippi must have been gigantic in summers when some of the glacier ice did melt.
    - thaumasiotes 4y ago
      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.
pazimzadeh 4y ago
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
- EdwardDiego 4y ago
  Square-cube law - larger animals retain heat better.
EdwardDiego 4y ago
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 https://en.wikipedia.org/wiki/Square–cube_law
- WallabyEV 4y ago
  Interesting note and a curious thing to apply in my local area. We have lots of cross breed lizards like horned toads and newts and anoles. We love their feeding habits. Compared to the rainforest lizards, our prairie ones are 4x larger on average. Like dwarf iguanas in some respects with large claws and speed. I’m also a huge fan of dragonflies here in north Texas - quite common seeing 3-5” long ones zooming about with gorgeous variety of colors. I’ve noticed they appreciate outdoor fans and treat the breeze path as a playground.
- chrisco255 4y ago
  The earth was much warmer during the era of dinosaurs, and yet they still grew to such sizes. I'm not sure that body heat retention is a great explanation, especially given the thick fur coats of most modern mammals that were evolved for the cold. I'm mostly curious how the ecosystem was able to support so many large animals, from the base layer of the food chain up. If there was an ice sheet a mile thick covering all of Canada down to Wisconsin, then most of north America must have been tundra. Were there less trees? Did grasslands thrive across the continent which supported ruminants more, which in turn provided more food for large predators?
  - EdwardDiego 4y ago
    Fair comment. :) I was referencing Bergmann's Rule [0], which really only applies to warm blooded animals but there's also a theory that evolving a larger size helps ectotherms maintain a stable temperature also. [1], and relating to your question on carrying capacity of the food available - the Jarman-Bell Principle [2] that larger herbivores can subsist better on low quality food than smaller herbivores. And, for interest, Allen's Rule on body appendages for temperature regulation. [3] There's also Cope's Rule - that animals just tend to evolve to get larger, until that's no longer viable. [4] I can't comment on how valid any of them are, as I'm just an armchair biologist :D [0]: https://en.wikipedia.org/wiki/Bergmann%27s_rule https://en.wikipedia.org/wiki/Bergmann%27s_rule [1]: https://en.wikipedia.org/wiki/Gigantothermy https://en.wikipedia.org/wiki/Gigantothermy [2]: https://en.wikipedia.org/wiki/Jarman-Bell_principle https://en.wikipedia.org/wiki/Jarman-Bell_principle [3]: https://en.wikipedia.org/wiki/Allen%27s_rule https://en.wikipedia.org/wiki/Allen%27s_rule [4]: https://en.wikipedia.org/wiki/Cope%27s_rule https://en.wikipedia.org/wiki/Cope%27s_rule
DrBazza 4y ago
Glyptodons in South America made huge burrows: https://www.discovermagazine.com/planet-earth/get-lost-in-mega-tunnels-dug-by-south-american-megafauna 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...
- greggsy 4y ago
  I’ve read that sloths we’re responsible for spreading avocado seeds, but it makes me wonder whether those seeds were always that large?
  - DrBazza 4y ago
    Yes. I used avocados as an example because everyone is well aware how large the seed is. I couldn't find the original reference, but there's a few papers on how there are South American plants that now geographically isolated because there's no megafauna to eat and disperse the seeds.
- brnt 4y ago
  I'm assuming any fruit or veg grown by humans are heavily tuned versions of some wild ancestor, and may seem to have little in common with it. How 'original' are the avocados we all know and love?

mlindner 4y ago

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?

mc32 4y ago
It’s not even the Mississippi River it’s a log chute arm of the river. If you look up top you can see where the arm ends.
guelo 4y ago
It's just a tooth but it's pretty cool https://www.sunherald.com/news/state/mississippi/article268277647.html?utm_source=pushly&intcid=pushly_2480125 https://www.sunherald.com/news/state/mississippi/article2682...

gpvos 4y ago

The American Lion: it's BIGGER than other lions!

shard 4y ago

In a similar vein, the drying of Lake Mead is revealing bodies of victims of accidents and foul play: https://www.thefocus.news/culture/why-is-lake-mead-drying-up-fourth-set-of-human-remains-discovered/ https://www.thefocus.news/culture/why-is-lake-mead-drying-up...