Q&A: Animals in Extra Large In general, the large size of some prehistoric animals in comparison to their modern counterparts had to do with evolutionary opportunity. Share: Facebook Twitter Google+ Stumble Digg Email ThisBlogThis!Share to XShare to Facebook Related Posts:Nonfiction: A History of the Heart, That Most Vital of OrgansTrilobites: Tiniest Ape Ever Discovered Hints at the Rise of the MonkeysOzone layer is making a comeback and will be FULLY recovered by 2060 – UN reportGlobal Health: Dogs Can Detect Malaria. How Useful Is That?Ruth Gates, Who Sought to Rescue Coral Reefs, Is Dead at 56Cancer Society Executive Resigns Amid Upset Over Corporate Partnerships