the idea that entire species could irreversibly disappear initially met with a lot of resistance. The concept of extinction must have been at least as difficult to reconcile with predominant beliefs back then as man-made climate change is for many today. The English geologist Charles Lyell, Charles Darwin, and Georges Cuvier all helped advance its acceptance—but not necessarily deliberately, and certainly from very different perspectives.
What about the people who wiped out the Dodo? Surely, if anyone demonstrated extinction in that time period, it was those folks.