Walking Began Underwater

Lungfish,of West Africa, have been discovered by scientists of the ability to walk on its fins. The fish, which does not even have feet, is being claimed by researchers to be the originator of "walking" .This is where humans learnt it from, they say.
"We found that the lungfish uses a range of gaits, from walking (alternating the limbs) to bounding (moving the limbs synchronously)," said King, a biologist studying at the University of Chicago.

[1]National Geographic. See full article