Many animals may have been spared extinction by humans due to the fact that the western world thought they were myths, until late in the second millennium AD when furthering exploration brought back evidence of their existence. Among them: tigers, komodo dragons, giant squid, giraffe, pandas, gorillas.
http://www.sciencemag.org/news/2014/03/why-did-new-zealands-...
If anybody wants to read an extremely complete book on the subject, it's hard to do better than A Feathered River Across The Sky[0]. It's well written and the science is sound.
[0]: https://www.amazon.com/Feathered-River-Across-Sky-Extinction...
New Zealand also has some horrifying stories (the last group of a thought to be extinct bird was killed by a lighthouse owners cat after he’d sent one to be identified. I hate cats.)