What types of evidence support the existence of a past supercontinent like Pangaea?

• A. Current coastlines only.
• B. Matching coastlines, identical fossil distributions, similar rock belts, and paleomagnetic data indicating coordinated movement.
• C. Magnetic field strength today.
• D. Age of recent sediments.

Answer: (B)

Evidence for a past supercontinent comes from several lines of data that, together, show the continents were once joined and have since drifted apart. The coastlines of continents like Africa and South America line up in a way that suggests they fit together as puzzle pieces, indicating they were connected long ago. Fossil distributions across now-separate landmasses are striking: identical or closely related species and plant fossils appear on continents that are far apart today, implying those lands shared a common ecosystem when they were one piece. Rock belts and mountain ranges also line up when the continents are rearranged into a single configuration, with matching rock types, ages, and deformation patterns linking regions across oceans.

Paleomagnetic data add a crucial clock and location to the story. When rocks form, minerals lock in the direction of Earth’s ancient magnetic field. By dating those rocks and comparing their recorded magnetizations from different continents, scientists reconstruct past latitudes and orientations. The results fit a scenario in which the landmasses were attached and moved together as one large crust before fragmenting and drifting apart.

Old or current magnetic field strength or the ages of only recent sediments don’t address how continents were arranged in the deep past, so they don’t provide the same explanatory power. Together, the coastlines, fossils, rock correlations, and paleomagnetic records create a consistent picture of a former single supercontinent that later broke apart.