Why are we certain there was no land bridge to dinosaurs walk across the atlantic ocean from south america to africa?

Approximately how many million years older than bedrock layer b is bedrock layer d

Acity developer is considering building an amusement park near a local river. what tool would the developer predict the future path of the river? a. series of city maps from nearby cities b. series of topographic maps in chronological order c. guide map of the new amusement park d. thermal map of the area

Which are evidence of the seafloor spreading? a. molten material b. magnetic stripes c. continental material d. drilled core samples e. ocean water samples