See the chart in https://phys.org/news/2020-08-dinosaur.html
There's some debate over how useful this is for dinosaurs, but something that died out 10k years ago with closely related existing species is probably easier.
> Stable isotopes suggest that Castoroides probably predominantly consumed submerged aquatic plants, rather than the woody diet of living beavers. There is no evidence that giant beavers constructed dams or lodges. The shape of the incisors of Castoroides would have made it much less effective in cutting down trees than living beavers. It was likely heavily dependent on wetland environments for both food and protection from predators.
Day or night?
That was a trick question. Day.
Easy. The Beaver. If it were not for beavers evolving beside us, the Eastern US and much of the world would very nearly resemble the driest American Southwest of today, with rain being gathered after a brief overland wash into deep river gorges, with little water left behind close to surface. Past a certain age of erosion even introducing beavers would not help. Shallow masses of water diverted overland is crucial to sediment distribution and the formation of oxbow lakes. If beavers had arrived late their industry would be slowing rivers already confined by steep gorges and the violence of waters would carry them away and destroy them and their families.
When beavers are gone and what is left is the flaky erosion patterns of human desire the future landscape will be a crap shoot... for humanity could never match the attention and focus of the beaver.
Drainage paths in the West ( https://i.dailymail.co.uk/i/pix/2016/10/21/16/3995911F000005... ) were more narrow and violent, the same in the East were not. A minimum of sudden deep erosion and therefore sideways diversion of blocked watercourses would be necessary for beavers to get established and shape the landscape so in the East they did. Other places in the world like the Amazon may have been shaped by vegetation impeding erosion more so than gnawing creatures.
The rainfall patterns are very different in those two areas. I don't doubt that beavers have important erosion and sediment retention impacts that over time do have a massive impact on the ecosystem and landscape. However, sediment rention is far from only reason why the american SW looks so different from other parts of the country.
The eastern US pretty much wiped out beavers as most landowners view beavers as pests. Does not look anything like the southwest. If we introduce beavers to nevada, do you think nevada will look like upstate ny?
> much of the world would very nearly resemble the driest American Southwest of today
Most of the world doesn't have any beavers. Most of the world does not resemble the american southwest.
Rather than beavers creating the environment, it's the environment that created the beavers. Beavers exist in areas with plentiful rain/water for a reason. Look up rainfall patterns in the US and you'll see how illogical your argument is.
...and killing them.
It's curious how megafauna extinctions coincide with human arrival... Native Americans, Australian Aborigines, and other "First Peoples" were just as deadly as later European settlers.
The Once and Future World by J.B. MacKinnon eloquently describes our disastrous impact on Nature: https://www.jbmackinnon.ca/the-once-and-future-world
That's one possible, maybe even likely scenario.
But humans started moving around at that time for a non-human reason; the end of the Ice Age. There's some evidence for populations of large mammals dying out before humans are believed to have showed up in those places, like Australia.
(As with most changes of this magnitude, the true answer is probably "more than one thing".)
We're the reason the North American continent has _no_ large predators except bears.
We humans nearly bought it during the same period; we bottlenecked at ~1,000 individuals for millennia. https://www.science.org/doi/10.1126/science.abq7487
The other hominins didn’t make it.
Not true.
But somehow ALL the megafauna in Australia, Asia, and North America went extinct at approximately the same time humans arrived.
Native americans and australian aborigines arrival coincided with drastic climate change. Or put another way, climate change was a major driver of human migration.
> were just as deadly as later European settlers.
Unless natives and aborigines had guns, railroads, mass farming, etc, I highly doubt it. Not to mention the population boom due to modern medicine and mass migration.
If you consider the relatively small native american and aborigine populations, the technology involved and how gigantic america and australia is, it's absurd to think natives or aborigines wiped out the megafauna.
Species extinction has two major causes - climate/environment change and loss of habitat. Were the natives and aborigines sophisticated enough to cause climate/environment change or develop farming to a degree that deprived the megafauna of their habitats? I highly doubt it.
Aside from the plausible scenario of driving whole herds off cliffs (because it was safer than trying to separate one or two from the herd).
https://en.m.wikipedia.org/wiki/The_Sixth_Extinction:_An_Unn... is a pretty fun read about how we've destroyed everything in our path.
https://blog.hmns.org/2017/04/the-founding-father-and-the-fi...
flerchin•7mo ago
kcplate•7mo ago
yodon•7mo ago
SketchySeaBeast•7mo ago
jandrewrogers•7mo ago
These days you are unlikely to have a chance to try it unless you are friends with a trapper.
rbanffy•7mo ago
Scarblac•7mo ago
It was argued that their tails are scaly like a fish', and of course they live in water. But on the other hand there's all the fur and so on.
So eventually it was decided that beaver tails count as fish, not the whole animal.
This led to it being hunted to local extinction in quite some places.
gausswho•7mo ago
- How does beaver taste?
- How does beaver tail taste?
mousethatroared•7mo ago
dlcarrier•7mo ago
maximus-decimus•7mo ago
condensedcrab•7mo ago
https://www.detroitcatholic.com/news/the-history-of-detroit-...
WorkerBee28474•7mo ago
https://www.patheos.com/blogs/geneveith/2013/02/alligator-is...
jnaina•7mo ago
electricboots•7mo ago
A shame really, youth is wasted on the young.