Early 20th-Century View on Transoceanic Animal Migration

In the early 1900s, the prevailing scientific explanation for how land animals crossed oceans was land bridges. Geologists and biologists hypothesized that now-submerged continental connections (e.g., Beringia, "Lemuria," "Atlantis") once allowed faunal dispersal. This "land-bridge theory" dominated until plate tectonics and paleomagnetism (1960s) confirmed continental drift, showing that continents themselves moved—carrying their biota—rather than rising/sinking bridges.