Geologists have long thought that meandering rivers, with their gently swooping banks, are a geologically recent feature. According to the rock record, these rivers began proliferating around 450 million years ago in the Silurian period, coinciding with the spread of plants on land. The prevailing idea was that plants would have stabilized riverbanks, leading water to flow in concentrated, meandering channels rather than forming chaotic braided river systems in loose sediments.
Click here for original story, Mud could have made meandering rivers long before plants arrived
Source: Phys.org