Today, bony animals are some of the most diverse organisms on Earth, but it wasn’t always that way. This episode, we explore what features distinguish vertebrates from their closest relatives, and we dive into the abundant evidence from genetics, embryology, and the fossil record that gives us a glimpse at how our distant ancestors came to be.

In the news: swimming hands, early life, Dunkleosteus jaws, and Neanderthal noses

Time markers: Intro & Announcements: 00:00:00 News: 00:05:35 Main discussion, Part 1: 00:42:55 Main discussion, Part 2: 01:21:55 Patron question: 02:05:55

Check out our website for this episode’s blog post and more: http://commondescentpodcast.com/

Join us on Patreon to support the podcast and enjoy bonus content: https://www.patreon.com/commondescentpodcast

Got a topic you want to hear about? Submit your episode request here: https://commondescentpodcast.com/request-a-topic/

Lots more ways to connect with us: https://linktr.ee/common_descent

The Intro and Outro music is “On the Origin of Species” by Protodome. More music like this at http://ocremix.org

Musical Interludes are "Professor Umlaut" by Kevin MacLeod (incompetech.com). Licensed under Creative Commons: By Attribution 3.0 http://creativecommons.org/licenses/by/3.0

Nearly 400 million years ago, an unusual group of fish gave rise to the first land-dwelling vertebrates. Since then, their descendants have repeatedly moved back into the water. This episode, we explore the many ways these species adapt to the challenges of turning a terrestrial body into one that can survive at sea, and we investigate some of the most famous and confusing cases from the fossil record.

In the news: post-extinction oceans, croc eggs, damaged dino tails, and meat-eating dung beetles.

Time markers: Intro & Announcements: 00:00:00 News: 00:05:45 Main discussion, Part 1: 00:40:15 Main discussion, Part 2: 01:31:35 Patron question: 02:30:30

Check out our website for this episode’s blog post and more: http://commondescentpodcast.com/

Join us on Patreon to support the podcast and enjoy bonus content: https://www.patreon.com/commondescentpodcast

Got a topic you want to hear about? Submit your episode request here: https://commondescentpodcast.com/request-a-topic/

Lots more ways to connect with us: https://linktr.ee/common_descent

The Intro and Outro music is “On the Origin of Species” by Protodome. More music like this at http://ocremix.org

Musical Interludes are "Professor Umlaut" by Kevin MacLeod (incompetech.com). Licensed under Creative Commons: By Attribution 3.0 http://creativecommons.org/licenses/by/3.0

The dome-headed dinosaurs are some of the most iconic ancient reptiles, but they’re surprisingly unexplored compared to other dinos. This episode, we explore what makes these dinosaurs unique, what limits our understanding of them, and the many confounding mysteries that paleontologists have been scratching their heads over, including the question of what exactly they were doing with those thick heads.

In the news: the I Know Dino children’s book, giant reptile locomotion, and dinosaur hooves.

Time markers: Intro & Announcements: 00:00:00 News: 00:08:45 Main discussion, Part 1: 00:46:32 Main discussion, Part 2: 01:12:05 Patron question: 02:05:30

Check out our website for this episode’s blog post and more: http://commondescentpodcast.com/

Join us on Patreon to support the podcast and enjoy bonus content: https://www.patreon.com/commondescentpodcast

Got a topic you want to hear about? Submit your episode request here: https://commondescentpodcast.com/request-a-topic/

Lots more ways to connect with us: https://linktr.ee/common_descent

The Intro and Outro music is “On the Origin of Species” by Protodome. More music like this at http://ocremix.org

Musical Interludes are "Professor Umlaut" by Kevin MacLeod (incompetech.com). Licensed under Creative Commons: By Attribution 3.0 http://creativecommons.org/licenses/by/3.0