Why were prehistoric era animals so gigantic in comparison to animals from the “modern era”

Question

Why were prehistoric era animals so gigantic in comparison to animals from the “modern era”

In: 1281

Answer 1

The question to ask is why did megafauna species suddenly start going extinct when humans appeared on the scene. The answer is pretty obvious – we killed or domesticated as many of them as we could. The largest and juiciest hunting targets have generally suffered the worst when it comes to cohabitation with humans.