Over the past several hundred thousand years, Australia has witnesed numerous ice age cycles, ecosystems dominated by giant marsupials, the arrival of humans, the extinction of those giant animals, and more. And there may be no better window into this dynamic time period than the world-famous Naracoorte Caves of South Australia. In the news: an infected dinosaur, humans' earliest steps in Canada, horny dinosaurs, and a four-eyed ancient lizard.Time markers: Intro & Announcements: News: Main discussion, Part 1: Main discussion, Part 2: 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/CommonDescentPC Facebook: https://www.facebook.com/commondescentpodcast/ PodBean: https://commondescentpodcast.podbean.com/ iTunes: https://itunes.apple.com/us/podcast/the-common-descent-podcast/id1207586509?mt=2 YouTube: https://www.youtube.com/channel/UCePRXHEnZmTGum2r1l2mduwThe 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 3.0 http://creativecommons.org/licenses/by/3.0/