In the Middle of a thick forest a pair of small dog-size animals happily nibble at the tender leaves of a low-growing bush. Above them, birds flit through the treetops, filling the hot, moist air with honks and shrill whistles. Another bird is also on the scene. But this one is quiet to stands upright, and not on a tree but next to it, on the ground. This bird is huge, at least 6 feet tall. Without pausing to think, the small animals whirl away from the bushes and start running wildly through the forest. Right behind them the feathered beast runs, its huge feet thundering on the ground. Nearly on top of the panicked animals, the bird opens it enormous beak and slices downward. The giant bird is Gastornis!