…how much more dangerous would it be than going back 20,000 years say? [To eliminate the effects of the Pleistocene extinctions as well as the subsequent civilization and industrialization trends.]
What would you need to bring with you to stay alive? Would anything less than an armored combat vehicle give you a chance? Is a T-Rex or a Raptor going to be more dangerous than any Pleistocene predator? Howzabout a swim in the ocean, and a Mosasaur vs. a shark (yes I know sharks were around back then too).
Primitive humans would be far more dangerous than dinosaurs. Especially if they carry diseases you have no immunity to. I think I would fair almost as well in a Pleistocene wilderness as I would in a modern one. Meaning, not well at all.
With humans you can try empathy at least, as well as aggression or, more sensibly, running away. We know that human ancestors like Denisovans and Neanderthals made sweet hominid love, because we found their child. I assume that was an entirely consensual and respectful arrangement and showed that mixed marriages do work.
In the Pleistocene, in most places humans would not be only the apex predator or have modified their environment significantly to our benefit yet. I’d still be wanting a well-armoured vehicle, with good cross-country and stream-crossing ability since there are no roads, and probably bring all my food. I don’t see eating mammoth steaks or triceratops burgers as being safe or viable - it would be puny human v every hungry carnivore the moment you felled something (ideally in a titanic not-Tesla Truck / dinosaur combat).
I think that a person would fare much better against a T-rex than a polar bear, but only because it’s quite possible that a full grown T-rex might not even notice a human.
It’s those cute little ones that vomited all over Newman that would scare me the most.
If I get in a fight with a T. rex, I’m going to lose. But then, that’s also true of a grizzly bear. I’ve gone camping in a tent on land that’s in the natural habitat of grizzlies, and didn’t worry much about it, because even in the heart of their natural habitat, they’re few and far between. But that’s inherently true of apex predators anywhere, anywhen. T. rex can’t have been significantly more common than grizzlies.
Anything close to our size would probably mostly leave us alone, just because we look too much like a fair fight, and no animal ever wants one of those. And anything large enough to not be leery of us is going to be rare. Upshot, you don’t need any sort of armored vehicle at all.
Jurassic Park is different. There, there was a much higher density of predators than you’d find in the wild, because it’s a tourist attraction, and tourists want to see predators. But to make that happen, they have to import a lot of meat, raised in a much larger area than the island.
I assume that we could since oxygen levels were higher than they are now, and i’m assuming that anything additional that would prevent it would also impact our mammal ancestors.
On the other hand, if oxygen was at the high end of what I found in a web search, more like 35% than 25%, we might be adversely affected by too much oxygen, but I don’t know if 35% is too much oxygen or not.
Throughout the Mesozoic, oxygen levels were both higher and lower than today at various times. Both our ancestors and the dinosaurs as a group made it through.
I’m less worried about the fauna of ancient times than I am about the flora. Which berries and fruits are safe to eat, and which had developed to be poisonous to all those plant-eating dinosaurs (and tiny little mammals) we read about? And what about the water supply? Is it full of heavy metals, or perhaps dinosaurs have poop with a strain of E. coli to which I have no resistance?
This was my thought. What is there to eat? How safe are those berries. So many plants we eat have been selectively bred by humans to excessive proprotions to be especially larger food sources. Mammals barely existed. What about fruit-bearing trees, etc? Were there coconuts? IIRC grass did not exist yet, so no wheat. Bananas? Obviously local fauna could eat the plants, tthey must have had some nutritional value beyond cellulose.
People eat turtle, alligator, and (obviously) bird eggs (in all sizes, from quail to ostrich). On the evolutionary family tree, all three are Archosaurs. Turtles and alligators are like cousins from opposite sides of the family, and birds are a subtype of dinosaur. So I’d say that’s pretty strong evidence that at least some, if not quite a few, dinosaurs had edible eggs.
Both birds and crocs exhibit parental care, though; so with at least some dinosaurs, you could end up eaten yourself.
Oh yes, I’d assume that dinosaur eggs were edible and nutritious. I’ve even read a theory that mammals overtook dinosaurs because they are so many dino eggs.
I wouldn’t want to live just on eggs, but I suppose it’s not a terrible choice.
I doubt it; none of the diseases or parasites existing at the time will be adapted for humans, or even primates. For that matter it’s quite likely that they’d be much less interested in biting humans in the first place, not having adaptations to scent and target us like modern mosquitoes have.