The gang discusses two papers that use functional morphology to determine when echolocation evolved in two groups of mammals, whales and bats. Also, Curt rattles off a wikipedia page on hamburgers, James fights against physics, and Amanda would rather talk about how terrifying Basilosaurus is. Also, to cut this off at the pass, a correction. Bats are the "SECOND" most diverse mammal group and rodents are the most diverse.

References:

Simmons, Nancy B., et al. "Primitive Early Eocene bat from Wyoming and the evolution of flight and echolocation." Nature 451.7180 (2008): 818-821.

Park, Travis, Erich MG Fitzgerald, and Alistair R. Evans. "Ultrasonic hearing and echolocation in the earliest toothed whales." Biology letters 12.4 (2016): 20160060.