From Today in Science History:
David Grandison Fairchild (Died 6 Aug 1954; born 7 Apr 1869). American botanist and plant explorer who supervised the introduction of over 20,000 exotic plants and varieties of established crops into the U.S., including soya beans, mangos, alfalfa, nectarines, horseradish, and flowering cherries. He spent 37 years seeking new and useful plants by travelling the world including the South Sea Islands, Australia, New Zealand, New Guinea, Japan, China, the Persian Gulf, Africa, the West Indies, and South America. In 1898 he set up a small plant introduction garden on a six-acre plot near Miami, Florida, especially interested in aesthetically valuable or economically useful exotic fruits and plants. He managed the Foreign Seed and Plant Introduction program of the U.S. Dept. of Agriculture (1906-28).
Florentino Ameghino (Died 6 Aug 1911; born 19 Sep 1853). Argentine paleontologist and anthropologist who made significant contributions to the field of vertebrate paleontology and established the Pampas region of Argentina as a rich source of fossils. He discovered over 6,000 fossil species and classified 35 suborders of mammals. Ameghino's controversial discoveries of stone implements, carved bones, and other signs of a human presence in Argentina during the Pliocene, Miocene, and earlier periods served to increase his worldwide fame.