Yes and no. If dinosaurs originally evolved from something like a para-crocodilian, and the K-T extinction set things back to zero as far as land megafauna went, the question might be why archosaurs didn’t take over again. One possible hypothesis is that this time around marsupial and placental mammals had evolved, and not laying eggs might have presented advantages. During the Mesozoic mammals might not have been able to evolve into megafauna in the face of competition from already established archosaurs, but in the Cenozoic mammals got ahead of the competition.
I think humans could survive in the Mesozoic provided they had the training and knowledge to cope with the predators they might face. The very largest theropods might not have bothered with anything as small as a human unless the human walked past their nose while they were hungry. Humans were historically able to adequately defend themselves against lions, tigers, leopards, bears and hyenas. Humans learned to be dangerous with ranged weapons– atlatls and bows & arrows, which meant not always having to go face to face with a dangerous carnivore. As well as sneaky cheating like poison, pit traps, nets and ropes. Possibly humans would have learned to make body armor out of dinosaur hide if that was any help. It might not have been easy, but walled villages and killing the worst predators in the immediate vicinity might have been doable.
Yes, it is a matter of scaling up to entrap large prey and the toughness to avoid being damaged by it. And I’m saying that is probably profoundly unlikely.
I will confirm that ostrich tastes like beef. I conjecture that the difference is between flying muscles and those used for terrestrial locomotion. I would expect that all non-flying dinos will taste like beef. Or lamb. Finding edible (and digestible) veggies is likely harder. I know that there were nuts and seeds. Or 56 MY ago there were since that seems to have been what got the mammals past the K-T event.
Annnd after finding the above non-fictional video this morning, I then discover this new cinematic release this weekend:
Where a whole suburban neighborhood is transported back to 150 million years ago, and the residents have to find a way to survive against the rampaging Allosauruses et al.
It may be that the crocodilians, being the one of only 2 clades of archosaurs to survive the C-T boundary, were too “conservative” and constrained to have at least one descent line evolve back into something resembling non-avian dinos, and birds & mammals were able to outcompete them for the vast majority of niches in any event.
I concur. Plants big enough to eat humans are pretty well impossible.
The manchineel tree (Hippomane mancinella), has poison sap, and supposedly if you are stupid enough to fall asleep under one, you can die. But it is not “carnivorous”.
