Scientists have uncovered evidence that a massive earthquake rerouted the Ganges River 2,500 years ago in what’s now Bangladesh.

A new study suggests an earthquake of estimated magnitude 7.5 or 8 shook the Indian subcontinent 2,500 years ago, changing the course of the Ganges.

As the sun sets over a serene stretch of the mighty Ganges, a pair of smooth, grey dolphins arch gracefully out of the water, bringing hope that wildlife can again call India's great river home.