Joseph Leidy
"Archaeotherium" was named by Joseph Leidy (1850). Its type is "Archaeotherium mortoni". It was synonymized subjectively with "Entelodon" by Leidy (1853) and synonymized subjectively with "Elotherium" by Leidy (1857). It was assigned to Entelodontidae by Leidy (1850), Peterson (1909), Scott (1940), Galbreath (1953), Russell (1980), Carroll (1988) and Effinger (1998).