Walking whale and brachiating octopus
A couple of pages from the Aquaman story, "A World Without Water," in ADVENTURE COMICS# 251, August 1958. It's a typically over-the-top Silver Age premise. A nuclear explosion sends Aquaman ahead five thousand years to the amazing year 6,958. There's the usual futuristic gadgets and wardrobe, but the crucial thing for Aquaman is that the world's oceans and seas have dried up. Not only that, but sea creatures like whales, mantas and flying fish have been adapt to successfully adapt to the change.You could write a thesis on all the reasons this premise is just wrong, wrong, wrong. But there are a few things to remember.
First, unlike comics from around 1970 on, Golden Age and Silver Age comics were deliberately aimed at a juvenile readerships. There were always a few older fans of course, but in general titles were designed to appeal to kids up to junior high. It was Stan Lee who started trying to win over high school and college students and older. So these stories work on a sort of fairy tale logic where things make sense on an emotional or symbolic level, rather than a rational one.
Also, I don't think it has been emphasised but many (if not nearly all) writers and artists did not have a full education. During the Depression, children frequently skipped school to help support their families with every penny they could bring in. Those were desperate times. Then came the war, where a young man had to defend his reasons for not enlisting, pressure to join up was so great. It wasn't until the servicemen returned and the GI Bill helped with costs that most people could think about college. So writers in the 1940s and 1950s were working with what they picked up from their own reading, and much of that was as flawed or superficial as what you would get from trying to be educated by watching TV today.