Episode 22 is all about megatherium, the giant extinct ground sloth--and a little bit about glyptodon, the giant extinct...thing. Megatherium vs trees was basically no contest. Giant ground sloth FTW! Giant sloth big, yeah yeah yeah, it's not small, no no no Glyptodon. Like a giant armadillo that can't roll up and doesn't need to. Show transcript: Welcome to Strange Animals Podcast. I’m your host, Kate Shaw. For this week’s episode, let’s learn about some Ice Age megafauna! But first, a quick note about my schedule. I’ll talk more about this in a few weeks, but in August I’m going to be in Helsinki, Finland for WorldCon 75. I don’t have the final schedule yet, but I am going to be on a panel about podcasting. If you’re going to WorldCon too, or if you’ll be in Helsinki the week of the convention or the week after, let me know so we can meet up! I’ll also be in Oslo, Norway for part of the day on August 7. I got a cheap flight to Helsinki because it has an 11-hour layover in Oslo, but to me that’s a bonus. Oslo has birds! Birds I’ve never seen before! So if you’re going to be in Oslo on August 7 and you’d like to meet me for a birding trip and/or lunch, definitely let me know! And don’t worry, I’ll schedule episodes ahead of time so you can continue to learn about strange animals even while I’m gone. Now, on to the megafauna. Until about five million years ago, South America was a big island continent the way Australia is today. As a result, many of the animals that evolved there at the time don’t look anything like animals in other parts of the world. The various species of giant ground sloth, such as Megatherium and Eremotherium, were South American mammals that lived from around 30 million years ago until only about 10,000 years ago—but we’ll come back to that in a minute. Those two species were huge—as big as African elephants. It was 20 feet long and stood more than 12 feet high on its hind legs. They liked woodlands and grasslands and ate plants. Megatherium had huge curved claws on its forefeet just like modern sloths, four claws that were a foot long each, and we know it walked on the sides of its paws as a result because we have some fossilized tracks. A ground sloth could walk on its hind legs, at least for short distances, and when feeding it spent a lot of its time reared up on its hind legs, helped to balance by its thick tail. It could reach branches some 20 feet off the ground that way. It hooked the branches down with its claws to eat the leaves. Around 5 million years ago, South America became connected to North America by the Central American Isthmus, which is volcanic in origin. Over the millennia, peaking around 3 million years ago, North American animals migrated south, and South American animals migrated north, called the Great American interchange. A lot of South American megafauna went extinct with the increased competition for resources, but nothing bothered the giant ground sloths. One medium-sized species, named Megalonyx by Thomas Jefferson, spread throughout North America as far north as Alaska. It was “only” about 10 feet long and weighed some 800 pounds, with three claws on its forefeet. The North American sloths died out first, around 11,000 years ago. It didn’t take long for most of the South American sloths to go extinct too, a little over 10,000 years ago. And yes, that was the same time that humans were spreading deeper into the Americas. It’s not a coincidence, although climate change after the last big ice age probably played a part too. Ground sloths had thick skin reinforced with osteoderms, knobs of bone tissue that grow in the skin like armor, so killing one would have been a lot of work for our ancestors, and was undoubtedly dangerous too. But a whole lot of islands make up the Carribbean, and giant sloths lived on some of those islands. Many had developed in isolation long enough that they’re now considered separate species from the m...