Final answer:
Sedimentary rocks with riverbed structures found in the oldest parts of continental landmasses, or cratons, provide evidence of ancient rivers and streams.
Step-by-step explanation:
The evidence that has been found in cratons, which are the oldest parts of continental landmasses, that provides evidence of rivers and streams includes sedimentary rocks with riverbed structures. These structures, often identified as ancient riverbeds or stream channels, suggest that flowing water was present at the time these rocks were deposited. Fossils of ancient sea life discovered far from current oceans signify that landmasses have traveled, and multilayer rock formations trace the history of Earth's changes. Additionally, evidence of past volcanic eruptions, earthquakes, and erosion also supports the dynamic nature of ancient Earth.