Time to discuss some actually extinct animals. First Aaron talks about the history of the giant ground sloth. More specifically, why the giant tanky ground sloths went extinct yet the slow tree sloths survive to this day. Learn how the extinct ground sloth's legacy contributed to America's westward expansion and our collective love of guacamole. Rustin follows with the discovery of a bizarre tooth spiral. What is now known as the helicoprion still is a mystery to scientists today.