Ivan Yefremov, Russian paleontologist and author (d. 1972)
Ivan Antonovich (real patronymic Antipovich) Yefremov (Russian: Ива́н Анто́нович (Анти́пович) Ефре́мов; April 22, 1908 – October 5, 1972; last name sometimes transliterated as Efremov) was a Soviet paleontologist, science-fiction author and social thinker. He founded taphonomy, the study of fossilization patterns.