Schematic map showing the hypothetical geographic dispersion of apatemyids. Apatemyidae dispersed between North America and Europe via the Greenland Bridge and Thulean route; they dispersed from Europe to India probably through the Turgai Strait and/or along the Tethyan shore. Oldest apatemyids are recorded in the Paleocene of North America (Torrejonian) (Simpson 1940; McKenna 1963a; Szalay 1968; West 1973b). See text for explanations of the dispersal events. The exact timing of the dispersals of Apatemyidae in India is unknown but probably occurred in the Ypresian. Paleogeographic map adapted from Ron Blakey, Eocene (http://www2.nau.edu/rcb7/050Marect.jpg)