Which observation suggests continents once fit together like a jig-saw puzzle?

• A. The shapes of coastlines align across oceans
• B. Similar climate patterns in deserts
• C. Identical mountain ranges across all continents
• D. The presence of the same dinosaur species on all continents

Answer: (A)

Coastlines that line up across oceans show that the continents were once joined. When you match the edges of continents, like the eastern edge of South America with the western edge of Africa, they fit together like puzzle pieces. That visual fit points to a time when these lands were part of a single large landmass that later split apart as the tectonic plates moved.

This observation is supported by other lines of evidence, such as similar rock types and fossil species found on now-distant continents, which reinforce the idea of a shared, ancient connection. But the coastline alignment is the most direct and intuitive signal that the pieces of the continents were once one continuous surface.

Other ideas, like desert climate patterns, mountain ranges appearing across continents, or the same dinosaur species on different continents, don’t demonstrate a past global connection as clearly and can arise from unrelated processes.