Species: Likely Homo erectus (likely a direct ancester)

Oldest undisputed evidence of hominins walking upright efficiently, probably Homo erectus. Our style of upright walking is energetic and efficient. We use a long stride with a spring-like mechanism in the arch of our foot. These footprints found in Kenya are dated to 1.52 million BCE. They show evidence of a well-developed arch and a long stride ending in a propulsive toe-off of modern people.