It's been called the most diverse of all bones. It comes in an incredible variety of shapes and sizes, living and fossil, scattered across the mammalian family tree. It's called the baculum, the os penis, and in this episode we discuss what it does, who has it, what it means for paleontologists, and the evolutionary processes that made it what it is today. In the news: whales eating whales, pregnant plesiosaurs, robo-tetrapods, and the first American dogs. Time markers: Intro & Announcements: 00:00:00News: 00:05:30Main discussion, Part 1: 00:34:30Main discussion, Part 2: 01:15:00 Check out our blog for bonus info and pictures: http://commondescentpodcast.wordpress.com/ Follow and Support us on: Patreon: https://www.patreon.com/commondescentpodcast Twitter: https://twitter.com/CommonDescentPCFacebook: https://www.facebook.com/commondescentpodcast/PodBean: https://commondescentpodcast.podbean.com/ iTunes: https://itunes.apple.com/us/podcast/the-common-descent-podcast/id1207586509?mt=2YouTube: https://www.youtube.com/channel/UCePRXHEnZmTGum2r1l2mduw The Intro and Outro music is “On the Origin of Species” by Protodome. More music like this at http://ocremix.org. Muscial Interludes are "Professor Umlaut" by Kevin MacLeod (incompetech.com). Licensed under Creative Commons: By Attribution 3.0http://creativecommons.org/licenses/by/3.0/