Just in time for Halloween, Cara is joined by Dr. Lydia Pyne, the author of "Seven Skeletons: The Evolution of the World's Most Famous Human Fossils." A science historian with training in paleoanthropology, Lydia has special insight into the fossilized hominin ancestors many of us have grown to love, like Lucy, the Old Man of La Chapelle, and the Taung Child, to name a few. Follow Lydia: @LydiaPyne.