Final answer:
Geological and fossil evidence such as the fit of continents, matching fossils, and mountain ranges, as well as the calculation of the Mid-Atlantic Ridge spreading rate, supports the existence of the supercontinent Pangaea. Alfred Wegener's continental drift hypothesis laid the groundwork for the theory of plate tectonics, which was widely accepted in the 1960s.
Step-by-step explanation:
The existence of Pangaea is evidenced through various geological and fossil records which show that continents once fit together like a jigsaw puzzle. Alfred Wegener's hypothesis of continental drift suggested that matching fossils found across different continents and the fitting coastlines of South America and Africa were indications of a supercontinent. The Mid-Atlantic Ridge spreading rate calculation using the map provided by the USGS can further demonstrate the movement of tectonic plates consistent with the theory of continental drift.
Additional evidence for Pangaea includes matching mountain ranges found in different continents, suggesting they were formed together before the land masses drifted apart. The most massive extinction at the end of the Permian period, which is associated with the limited shallow coastal areas due to Pangaea's configuration, adds to this geological evidence.
Although Wegener's theory was not initially accepted, it would pave the way for the acceptance of plate tectonics in the 1960s, providing a mechanism for the movement of continents.