Aw, Julian May--I loved the Pliocene Exile series in high school: http://thewertzone.blogspot.com/2017/10/rip-julian-may.html ... http://file770.com/?p=25509 ... Her first SF sale from 1951 is online at the Internet Archive: https://archive.org/stream/Astounding_v48n04_1951-12_Gorgon776#page/n7/mode/2up