A new research article published in the journal Science proposes that humans were a key factor in the extinction of large land mammals since the Pleistocene Epoch, resulting in smaller-sized mammals over time. This in turn then radically changed land ecosystems. Biologist Dr. Felisa Smith coauthored the article with several paleontologists, including Paleontological Society members Kate Lyons and Jonathan Payne. To learn more about this study, please read Ed Yong’s explanation and critical discussion of their findings in The Atlantic and the article itself (both links below).
In a Few Centuries, Cows Could be the Largest Land Animals Left (Ed Yong, April 19, 2018, The Atlantic)
Body Size Downgrading of Mammals over the Late Quaternary (Smith et al., 2018, Science)