So if the ice age was after the flood, how did Noah etal survive and not the dinos?
This is a good question.
Obviously large dinosaurs (carnivorous or herbivorous) would have been under some sort of survival pressure due to a shortage of food and the Ice Age(s) could have tipped the balance for them.
Smaller animals (including mammals such as Noah) may have found it easier to survive, not having such high intake required. And Noah (and descendants) had the advantage of a higher order of intelligence to help in their struggle.
We observe that many fossils are found of smaller dinosaurs, down to the size of chickens and smaller. Why did these reptiles become extinct and yet similar size mammals (with similar sized appetites) survived, even thrived?
Graeme