Scientists long before Darwin wondered why whales, which are mammals, not fish, live in the sea. The discovery of the tiny vestigial hind limbs of Basilosaurus was a major breakthrough in the understanding of the evolutionary history of whales. World-renowned paleontologist Philip Gingerich will discuss the amazing discoveries of Basilosaurus and other ancestral whale fossils in the spectacular setting of the Exhibit Museum of Natural History, where a 50-foot specimen of Basilosaurus is now under construction. Reception follows.