Does the mane really make the lion? Certainly, luxurious locks are the feature that sets Panthera leo apart from the other large cats. But surprisingly, not all male lions have manes. And back in the early Pleistocene, manes covered more of the lion than just the head. Ari Daniel Shapiro speaks with archivist Connie Rinaldo of the Biodiversity Heritage Library and Harvard University and curator of mammals Bruce Patterson of Chicago’s Field Museum of Natural History to learn about the diversity of lions in the distant past and the challenges they face in the present.