Although most major rivers on Earth flow in a single direction from their source to the sea, the Amazon defies straightforward labels when we look into its ancient past. Before it became the colossal ...

Looking into it further, the team determined that the Amazon river really did flow in the opposite direction in the past. That team put the reversal down to a highland area in northeastern South ...

If there is lots of rainfall, or snow or ice melting, rivers sometimes rise over the top of their banks and begin to flow onto the floodplains at either side. Rivers meander where there is the ...