Wegener used evidence from climate to support his hypothesis of continental drift. He examined the distribution of certain fossil plants and animals, paying special attention to species that were not capable of long migrations or widespread dispersal. By matching the distribution of these species across different continents, he argued that they must've once been part of a larger landmass.

One example Wegener used was the presence of Glossopteris, a fern that lived during the late Carboniferous and early Permian periods. Glossopteris fossils have been found in South America, Africa, India, and Australia. Wegener proposed that these continents were once part of a single landmass, which he called Gondwana, and that the breakup of Gondwana led to the separation of these continents and the extinction of Glossopteris.