Follows the excavation of several groundbreaking finds in a corner of the Hell Creek Formation, an area famous for dinosaur fossils. As they investigate each new find, the team begin to paint a vivid picture of what life was like during this period.

While searching in the hills of North Dakota, palaeontologist Robert DePalma makes an incredible discovery: a prehistoric graveyard he names Tanis, featuring fossilised creatures as well preserved as the bodies found at Pompeii.