Archaeologists uncover a prehistoric grave containing our revolutionary cousin, see more in this clip from Season 1, "Aliens and Human Evolution." #AncientAliens Watch all new episodes of Ancient Aliens, Fridays at 8/7c, and next day on The HISTORY Channel website at ...

Ancient Astronaut Theorists believe that past evidence of ancient civilizations may have been destroyed. See more in this clip from Season 15, "The World Before Time." Watch all new episodes of Ancient Aliens, Fridays at 8/7c, and next day on The HISTORY Channel website at ...