In the earliest millennia of vertebrate life on Earth, the seas were home to the placoderms, a diverse group of extinct armored fish whose evolutionary innovations set the stage for some of the most important features of vertebrate life. This episode, we talk about some of history's most influential placoderms, with a special spotlight on the most famous of armored fish, the giant predator Dunkleosteus. In the news: asteroids and volcanoes, running lizards, Shawn's turtle, walking fish, and more on broken mastodon bones. Time markers: Intro & Announcements: 00:00:00News: 00:02:30Main discussion: 00:35:00 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 Podcast music is “On the Origin of Species” by Protodome. More music like this at http://ocremix.org.