Alfred Wegener proposed continental drift in 1912 and argued that the continents once formed Pangaea.
Wegener presented evidence from matching coastlines, related fossils and similar geological formations on continents now separated by oceans. He later developed the idea in his 1915 book The Origin of Continents and Oceans. His proposed supercontinent was called Pangaea.
Many geologists initially rejected the theory because Wegener could not identify a convincing mechanism capable of moving continents. Plate tectonics later supplied that mechanism through moving lithospheric plates and seafloor spreading. Wegener therefore became an important precursor of modern geology, although his original explanation was incomplete.