WEBVTT - What's the Difference Between Turtles and Tortoises? 0:00:01.920 --> 0:00:06.640 Welcome to brain Stuff, a production of iHeart Radio. Hey 0:00:06.720 --> 0:00:10.959 brain Stuff, Lauren Vogelbaum. Here, at some point, let's just 0:00:11.119 --> 0:00:14.440 say around two hundred and sixty million years ago, Earth 0:00:14.800 --> 0:00:20.239 got turtles. They look strange in these our modern mammalion times, 0:00:20.320 --> 0:00:24.360 when lots of things are squishy and unarmored, But during 0:00:24.520 --> 0:00:28.240 the Late Permian epoch, those early turtles were dressed in 0:00:28.280 --> 0:00:32.400 all the latest fashions, short sturdy legs, bony plates, and 0:00:32.440 --> 0:00:37.600 a stiff splayed crawling strut. Shortly after turtles made their 0:00:37.600 --> 0:00:42.160 evolutionary arrival, a fairly standard Earth thing happened a mass 0:00:42.200 --> 0:00:46.880 extinction event. Although mass extinctions have happened with some regularity 0:00:46.920 --> 0:00:49.800 on our planet, this one was a doozy, and it 0:00:49.840 --> 0:00:52.240 wiped out almost all of the life in the oceans 0:00:52.280 --> 0:00:55.360 and over two thirds of the vertebrates on land. The 0:00:55.440 --> 0:00:58.560 things that survived had to have been pretty good at survival, 0:00:59.160 --> 0:01:03.200 and it turns out turtles were. But we spoke about 0:01:03.280 --> 0:01:06.480 email with Laura Smith, a research scientists who specializes in 0:01:06.560 --> 0:01:09.760 herpetology at the Jones Center at ITUA, which is an 0:01:09.800 --> 0:01:13.280 organization in Newton, Georgia that promotes excellence and natural resource 0:01:13.360 --> 0:01:18.080 management and conservation. She said, turtles have a really successful 0:01:18.120 --> 0:01:20.839 body form that hasn't changed all that much over time. 0:01:21.400 --> 0:01:24.839 They've retained the primitive shell, which is a really protective, 0:01:25.000 --> 0:01:28.320 safe body design. Also, turtles live in a lot of 0:01:28.360 --> 0:01:32.760 different habitats. They're aquatic and also terrestrial, so living in 0:01:32.760 --> 0:01:35.280 a lot of different habitats has allowed them to persist. 0:01:36.760 --> 0:01:41.640 So well, what's the difference between tortoises and turtles. All 0:01:41.680 --> 0:01:44.559 of the animals alive today that protect themselves with a shell, 0:01:44.840 --> 0:01:47.920 which is basically just a modified rib cage, are in 0:01:47.960 --> 0:01:51.520 the order test studinies. Collectively, we call this group of 0:01:51.560 --> 0:01:55.320 animals turtles, but individually we might call them different things 0:01:55.360 --> 0:01:59.120 based on where they live and some morphological and physiological traits. 0:02:00.000 --> 0:02:03.639 Hortoises are a group that are generally always found on land. 0:02:04.640 --> 0:02:07.920 Smith said, they say that not all turtles are tortoises, 0:02:07.960 --> 0:02:12.560 but all tortoises are turtles. The turtles are organisms with 0:02:12.600 --> 0:02:15.440 a shell which might be in water or might be 0:02:15.520 --> 0:02:20.200 on land. A tortoise is a type of turtle. In general, 0:02:20.240 --> 0:02:23.359 both turtles and tortoises, as well as other reptiles, lay 0:02:23.400 --> 0:02:27.200 their eggs on land. It's what makes them different from amphibians, 0:02:27.240 --> 0:02:29.880 which need water for egg laying and at least part 0:02:29.919 --> 0:02:33.840 of their life cycle. Because tortoises are a type of turtle, 0:02:34.120 --> 0:02:36.919 it's difficult to lay down hard and fast rules about 0:02:36.919 --> 0:02:41.359 what makes something tortoises rather than turtle ish. But in general, 0:02:41.440 --> 0:02:44.640 tortoises are always found on land, whereas turtles can be 0:02:44.680 --> 0:02:47.919 found in aquatic or marine habitats as well as land. 0:02:48.880 --> 0:02:52.200 Smith said turtles and tortoises look different because of where 0:02:52.200 --> 0:02:55.160 they live. A sea turtle is only found in the ocean. 0:02:55.639 --> 0:02:57.720 The females are the only ones that come on land, 0:02:57.760 --> 0:03:00.960 and that's just to lay eggs. They have four legs, 0:03:00.960 --> 0:03:04.000 but the front legs are almost like wings or paddles. 0:03:04.440 --> 0:03:06.639 They're not great for moving around on land at all 0:03:06.720 --> 0:03:10.640 because they're adapted for swimming quickly. Their shells have a low, 0:03:10.760 --> 0:03:14.480 flat profile for cutting through the water. Compare that to 0:03:14.520 --> 0:03:17.519 a Galapa ghost tortoise, for example, whose body can weigh 0:03:17.560 --> 0:03:19.800 up to nine d and twenty pounds that's almost four 0:03:20.000 --> 0:03:23.720 d and twenty kilos. With stocky, elefantine legs, a high 0:03:23.720 --> 0:03:26.760 domed shell, and big scales on their exposed skin to 0:03:26.840 --> 0:03:30.480 protect them from predators, they wouldn't last long in the ocean, 0:03:30.800 --> 0:03:34.320 but luckily they don't have to. The Smith said, for 0:03:34.360 --> 0:03:37.200 the most part, there's not really one characteristic that tells 0:03:37.240 --> 0:03:39.680 you whether something is a tortoise or a turtle. But 0:03:39.760 --> 0:03:41.640 it's pretty clear. If you see a little turtle on 0:03:41.640 --> 0:03:43.280 the side of the road and it has a sort 0:03:43.320 --> 0:03:47.320 of flattened shell profile, webbed feet in the back, smooth skin, 0:03:47.400 --> 0:03:50.560 and some brighter colors, that's going to be a turtle. 0:03:51.160 --> 0:03:55.480 The tortoises have a heavier, more domed shell and subdued colors. 0:03:57.080 --> 0:04:01.760 As usual, the terminology can be confusing. Box turtles, for instance, 0:04:01.760 --> 0:04:04.280 which are widespread in the United States in Central America 0:04:04.600 --> 0:04:07.440 and don't really swim or spend much time in the water, 0:04:07.680 --> 0:04:11.160 but they're still considered turtles rather than tortoises. And then 0:04:11.160 --> 0:04:13.680 there are the terrapins, which is the name given to 0:04:13.720 --> 0:04:17.360 aquatic turtles in the United Kingdom. In the US, aquatic 0:04:17.360 --> 0:04:20.440 turtles are just called turtles, with the exception of the 0:04:20.520 --> 0:04:23.839 diamond back terrapin, which lives in brackish water in tidal 0:04:23.880 --> 0:04:28.279 marshes in the eastern United States. Both tortoises and turtles 0:04:28.279 --> 0:04:31.000 have made themselves at home on this planet. We find 0:04:31.080 --> 0:04:34.560 both on every continent other than Antarctica. With one exception, 0:04:35.080 --> 0:04:40.120 there are no tortoise species native to Australia. Smith said 0:04:40.520 --> 0:04:43.800 the greatest diversity of aquatic turtles are in Southeast Asia 0:04:43.880 --> 0:04:47.400 and in the southeastern United States. The greatest tortoise bio 0:04:47.400 --> 0:04:50.480 diversity is in South Africa. And there used to be 0:04:50.560 --> 0:04:53.320 more giant tortoises across the world, but now there are 0:04:53.360 --> 0:04:57.000 just remnants on the Galapagos and Aldebra places like that. 0:04:57.640 --> 0:05:02.440 Giant tortoises do occasionally disperse, or more likely drift across oceans, 0:05:02.839 --> 0:05:06.840 basically by surviving for weeks or months bobbing around. In 0:05:06.920 --> 0:05:09.840 recent years, an aldebrand tortoise with barnacles on its shell 0:05:10.120 --> 0:05:13.520 washed up in East Africa, and that's not bad for 0:05:13.640 --> 0:05:21.360 something that started its life in the Indian Ocean. Today's 0:05:21.360 --> 0:05:24.039 episode was written by Jesceline Shields and produced by Tyler Clang. 0:05:24.520 --> 0:05:26.440 For more on this and lots of other curious topics, 0:05:26.560 --> 0:05:29.160 is it has to Works dot Com brainstuff this production 0:05:29.160 --> 0:05:31.520 of iHeart Radio. For more podcasts from my heart Radio, 0:05:31.640 --> 0:05:34.320 visit the iHeart Radio app, Apple Podcasts, or wherever you 0:05:34.360 --> 0:05:35.520 listen to your favorite shows.