WEBVTT - Giants in the Earth: The Paleoburrows 0:00:03.040 --> 0:00:05.400 Welcome to Stuff to Blow Your Mind production of My 0:00:05.480 --> 0:00:14.840 Heart Radio. Hey, welcome to Stuff to Blow your Mind. 0:00:14.960 --> 0:00:18.400 My name is Robert Lamb, and I'm Joe McCormick. And 0:00:18.440 --> 0:00:21.759 I think today we're doing tunnels, Is that right? Yeah, 0:00:21.800 --> 0:00:26.159 we're going to venture into some strange tunnels in the earth. Um. 0:00:27.040 --> 0:00:28.880 I don't know about you, Joe, but I love a 0:00:28.920 --> 0:00:32.519 good creepy tunnel story. Um. You know, any caliber of 0:00:32.560 --> 0:00:35.000 motion picture. If you have like a subway tunnel and 0:00:35.159 --> 0:00:38.320 you have a monster shambling around down there, even possibility 0:00:38.320 --> 0:00:41.720 of a monster shambling around down there, I'm generally on board. 0:00:41.920 --> 0:00:44.440 Oh yeah, I mean it's one of the classics. And 0:00:44.600 --> 0:00:48.159 you know your your your your fairytale types. One of 0:00:48.159 --> 0:00:50.440 the big ones is you've got to go into the underworld, right, 0:00:50.479 --> 0:00:54.320 And what's closer in physical reality to an underworld than 0:00:54.480 --> 0:00:57.880 cave or a tunnel. Caves and tunnels, any humans have 0:00:57.880 --> 0:01:00.440 have long been fascinated by them. You know, we see 0:01:00.480 --> 0:01:02.760 a cave, we want to get in there. We need 0:01:02.800 --> 0:01:04.840 to know what's going on, we need to find out 0:01:04.840 --> 0:01:09.280 what kind of sacred uh secrets are contained in there. 0:01:09.800 --> 0:01:13.000 And so you know, I'm also continually fascinated by tales 0:01:13.080 --> 0:01:17.360 of of you know, modern tunnel systems, abandoned tunnel systems 0:01:17.440 --> 0:01:20.640 from from further back in history. UM. I also love 0:01:20.680 --> 0:01:23.440 a good you know, tunnel of unknown origin stories such 0:01:23.440 --> 0:01:28.120 as the Strange Tunnels and the Hyperion novels, or oh, 0:01:28.160 --> 0:01:31.360 another a film in this case that had some strange tunnels. 0:01:31.760 --> 0:01:35.399 There's the whole tunnel plotline in Jordan Peel's two thousand 0:01:35.480 --> 0:01:40.039 nineteen film US. Yeah. Yeah, let's not spoil anything about that. 0:01:40.200 --> 0:01:42.039 I'm not gonna spoil anything, but it does open with 0:01:42.080 --> 0:01:45.720 a with a fun text crawl, uh quote. There are 0:01:45.760 --> 0:01:49.000 thousands of miles of tunnels beneath the United States, abandoned 0:01:49.000 --> 0:01:54.120 subway systems, unused service roots, and deserted mind shafts. Many 0:01:54.200 --> 0:01:57.880 have no known purpose at all. So I instantly I was, 0:01:58.000 --> 0:02:00.320 you know, on board for that. I love a good 0:02:00.440 --> 0:02:04.600 informational legend like that. Uh. And the fun thing about 0:02:04.640 --> 0:02:07.040 that quote is that it's it's a fun one to 0:02:07.080 --> 0:02:09.160 ponder over because on one hand, it's sort of true. 0:02:09.160 --> 0:02:13.920 There are a lot of of of abandoned tunnel systems 0:02:13.960 --> 0:02:16.680 in the United States, some with some pretty engaging stories 0:02:16.680 --> 0:02:20.200 about them at times, you know, old minds, abandoned subway 0:02:20.280 --> 0:02:24.360 projects and abandoned subway lines. I'm a real I'm a 0:02:24.360 --> 0:02:29.320 real sucker for that sort of thing. Um. Also, you know, ultimately, 0:02:29.320 --> 0:02:32.040 I think this is the filming question is one that 0:02:32.080 --> 0:02:33.920 maybe doesn't you know, I supposed to take it completely 0:02:33.960 --> 0:02:36.680 seriously and think, well, there's this entire system of of 0:02:36.760 --> 0:02:38.680 tunnels and who knows what's going on down there? But 0:02:39.080 --> 0:02:42.600 it also reminds me of what we're talking about here today, uh, 0:02:42.639 --> 0:02:47.880 the story of mysterious tunnels uh and caves caverns in 0:02:48.240 --> 0:02:53.000 South America. Now, what makes today's example really interesting is 0:02:53.600 --> 0:02:56.640 normally you're going to think about your your mysterious tunnels 0:02:56.680 --> 0:03:00.160 in two categories. One is one is, obviously, you know, 0:03:00.200 --> 0:03:03.640 a cave of geological origin, you know, uh, oh, you know, 0:03:03.720 --> 0:03:07.400 here's here's a millions of years old cave with with 0:03:07.480 --> 0:03:12.040 stalactites and stalagmites, clearly a water formed cavity of some type. 0:03:12.680 --> 0:03:16.080 But then the other bucket, of course, is who made 0:03:16.120 --> 0:03:18.919 this tunnel, what human dug this and for what purpose? 0:03:19.560 --> 0:03:23.600 But actually, uh, those two categories leave out leave out 0:03:23.600 --> 0:03:27.000 another option, don't they? Yeah, and it's not aliens. The 0:03:27.760 --> 0:03:29.800 fun thing about this is you don't need aliens to 0:03:29.800 --> 0:03:32.520 get to the you know, the wow moment, to the 0:03:32.840 --> 0:03:36.000 to the amazing content of this particular topic, because we're 0:03:36.000 --> 0:03:39.600 still we still seem to be dealing with a non 0:03:39.760 --> 0:03:44.040 human entity U, a non human will behind these um, 0:03:44.080 --> 0:03:48.040 these these tunnels or caves or or burrows. Uh is 0:03:48.080 --> 0:03:51.360 probably more appropriate to call them these paleo burrows of 0:03:51.400 --> 0:03:54.520 South America. They're not the work of of a pre 0:03:54.600 --> 0:03:59.800 Columbian society. Uh, they're older and they're quite impressive. Well, 0:04:00.360 --> 0:04:02.080 as we dive in here, I want to mention that 0:04:02.560 --> 0:04:05.600 that one of my main sources here is an excellent 0:04:05.640 --> 0:04:10.040 book that came out, I believe in seventeen by Anthony J. Martin, 0:04:10.600 --> 0:04:15.360 a paleontologist at Emory University here here in Atlanta, titled 0:04:15.560 --> 0:04:20.599 The Evolution Underground Burrows, Bunkers, and the Marvelous Subterranean World 0:04:20.640 --> 0:04:24.440 Beneath Our Feet. Um. I've been meaning to cover this 0:04:24.480 --> 0:04:27.160 book in some form or another for a while, and 0:04:27.400 --> 0:04:29.320 I saw it on the shelf again. I was like, 0:04:29.320 --> 0:04:31.720 all right, today's the day I'm gonna I'm gonna bust 0:04:31.720 --> 0:04:34.080 this book out and see what grabs my attention. So 0:04:34.160 --> 0:04:36.480 I haven't read this yet, but my interest is piqued 0:04:36.560 --> 0:04:40.160 because I, like, you love a tunnel borrow a din 0:04:40.240 --> 0:04:43.800 under the earth. But I was familiar with Anthony J. 0:04:43.920 --> 0:04:46.840 Martin's name, and I'm not sure, but I think it 0:04:46.920 --> 0:04:51.040 was because he was one of the authors of research 0:04:51.160 --> 0:04:55.560 from two thousand seven that was famous for documenting the 0:04:55.760 --> 0:04:59.840 first fossil evidence of a dinosaur, the Doug Tunnels. Did 0:04:59.880 --> 0:05:02.400 you read about this, Yeah, this is covered in the 0:05:02.480 --> 0:05:04.840 in the in the book. Uh yeah, there's something some 0:05:04.920 --> 0:05:07.599 wonderful illustrations and even in one case, I believe a 0:05:07.640 --> 0:05:10.440 bit of folk art depicting these creatures, which I loved. 0:05:11.040 --> 0:05:14.000 Uh So the brief rundown on this. The paper where 0:05:14.040 --> 0:05:16.679 they described this find came out in two thousand seven 0:05:16.720 --> 0:05:20.040 and Proceedings of the Royal Society b Biological Sciences. It 0:05:20.200 --> 0:05:25.359 was by David J. Verrikio, Anthony J. Martin, and Yoshihiro Katsura, 0:05:25.839 --> 0:05:28.760 and it was called first trace and body fossil evidence 0:05:28.800 --> 0:05:33.960 of a burrowing Denning dinosaur. So this fossil find came 0:05:34.000 --> 0:05:38.520 from a formation in southwest Montanas near the border with Idaho. 0:05:38.560 --> 0:05:41.960 I think it's called the Black Leaf Formation, and this 0:05:42.120 --> 0:05:46.400 formation dates back to the mid Cretaceous period. The find 0:05:46.480 --> 0:05:51.039 consisted of both the trace fossil of the borough itself 0:05:51.240 --> 0:05:55.599 as well as skeletal fossils found inside. The skeletal fossils 0:05:55.640 --> 0:05:59.679 were of one adult and two juveniles, which apparently all 0:06:00.360 --> 0:06:04.719 and were fossilized inside the burrow. The dinosaur was a 0:06:04.720 --> 0:06:09.039 member of a previously undiscovered species of Ornithia, which the 0:06:09.080 --> 0:06:15.000 author's name or Ricto dromius cubicularis, and that genus name 0:06:15.120 --> 0:06:18.480 or Rictodromus that means digging runners that gives you a 0:06:18.560 --> 0:06:21.560 hint of like the two main talents of the stat 0:06:21.600 --> 0:06:25.600 build of this dinosaur. These would have been herbivorous dinosaurs 0:06:25.640 --> 0:06:29.560 that lived roughly ninety something million years ago. And so 0:06:29.680 --> 0:06:31.479 one question you might wonder is, well, how do we 0:06:31.520 --> 0:06:34.640 know that the dinosaurs we found inside actually made the 0:06:34.640 --> 0:06:37.520 tunnel or burrow instead of just I don't know, finding 0:06:37.680 --> 0:06:41.560 a a naturally occurring hollow or tunnel made by some 0:06:41.640 --> 0:06:45.320 other mysterious creature. Well, it seems likely that the dinosaurs 0:06:45.360 --> 0:06:48.599 themselves made it because of the creatures anatomy and because 0:06:48.640 --> 0:06:51.839 of its relationship to the borrow. So, in the words 0:06:51.880 --> 0:06:55.520 of the author's quote, the features of the snout, shoulder, girdle, 0:06:55.960 --> 0:06:59.080 and pelvis are consistent with digging habits. So it has 0:06:59.480 --> 0:07:03.560 multiple uh anatomical adaptations you would expect to find in 0:07:03.600 --> 0:07:06.719 a creature that specializes in digging. Like it's got a 0:07:06.720 --> 0:07:09.520 snout that is sort of fused together in a way 0:07:09.520 --> 0:07:11.600 that would make it kind of a good shovel for 0:07:11.680 --> 0:07:15.600 like kicking soil back and forth, and it's skeletal structure 0:07:15.640 --> 0:07:18.320 seems well put together to kind of brace itself with 0:07:18.440 --> 0:07:21.600 the back limbs or the pelvis as it uses its 0:07:21.600 --> 0:07:25.400 four limbs to dig and and throw soil out behind it. Yeah, 0:07:25.400 --> 0:07:27.640 this is something that's UH that's touched on with various 0:07:27.720 --> 0:07:32.520 organisms in this book that no organism needs the tools 0:07:32.760 --> 0:07:35.600 for burrowing or digging. But it's not just the you 0:07:35.640 --> 0:07:38.640 know something on matter having claws or some sort of snout. 0:07:39.240 --> 0:07:42.760 It also needs uh like the body to back it up. 0:07:42.800 --> 0:07:44.520 And so we can look at the bodies of many 0:07:44.520 --> 0:07:47.800 of these organisms that are extinct now and we can 0:07:48.040 --> 0:07:53.000 we can make very informed UH guesses about what their 0:07:53.040 --> 0:07:55.920 body had evolved to do. Right, you need the right 0:07:55.960 --> 0:07:58.720 kind of chassis to give you leverage with which to dig, 0:07:58.760 --> 0:08:01.680 because you remember, your digging is not just about what 0:08:01.800 --> 0:08:04.320 the hands are doing in the front. The four limbs 0:08:04.480 --> 0:08:07.480 scraping away at things. You all, the bracing is really important. 0:08:07.520 --> 0:08:10.560 You gotta hold your ground while you're scraping. Yes, yeah, 0:08:10.600 --> 0:08:13.640 you can't just put a big scoop on the front 0:08:13.680 --> 0:08:16.440 of your um. I don't know your prius and say 0:08:16.440 --> 0:08:20.160 you're gonna go out and start moving earth around. But 0:08:20.360 --> 0:08:24.000 another clue that that the dinosaurs inside this burrow dug 0:08:24.040 --> 0:08:28.200 it were the fact that the borrow almost perfectly matches 0:08:28.360 --> 0:08:31.520 the width and breadth of the torso of the adult. 0:08:31.680 --> 0:08:33.560 So it seems like this is a borrow of the 0:08:33.640 --> 0:08:35.880 right size to have been dug by the adult dinosaur. 0:08:36.080 --> 0:08:39.800 And the adult is found along with two juveniles inside 0:08:39.800 --> 0:08:42.320 the borrow, and they were found with no bite marks 0:08:42.480 --> 0:08:45.760 or anything on the bones, no signs of of carnivore 0:08:45.760 --> 0:08:48.320 bone assemblies like you might sometimes find where you know 0:08:48.440 --> 0:08:51.800 carnivore is dumping all the bones from its recent meals. 0:08:51.840 --> 0:08:55.000 So it looks like this was not just a tunnel 0:08:55.120 --> 0:08:59.000 dug by a dinosaur, but one that an adult dinosaur 0:08:59.320 --> 0:09:03.080 lived in side with its juveniles. And this would provide 0:09:03.120 --> 0:09:06.760 evidence of a case of extended parental care in dinosaurs, 0:09:06.800 --> 0:09:10.000 something that I think was uh less well evidenced and 0:09:10.120 --> 0:09:12.679 more controversial at the time, and based on the size 0:09:12.679 --> 0:09:15.959 of the juveniles, it appears that this parental care had 0:09:15.960 --> 0:09:19.200 gone on for at least several months. Yeah, yeah, this 0:09:19.280 --> 0:09:22.320 is a This is in stark contrast to some of 0:09:22.360 --> 0:09:28.440 the hypothesized ways that say, giant sauropods would have dealt 0:09:28.480 --> 0:09:30.880 with their young. I remember discussing that on the podcast, 0:09:30.880 --> 0:09:33.160 where like at least one hypothesis was the like the 0:09:33.160 --> 0:09:35.400 eggs kind of just fall out and they just rolled 0:09:35.480 --> 0:09:39.000 us aside and then they do their thing. So yeah, yeah, yeah, 0:09:39.320 --> 0:09:42.960 totally different parenting strategy. Anyway. The authors of this paper 0:09:43.440 --> 0:09:46.440 note that vertebrates today create burrows, of course for a 0:09:46.480 --> 0:09:49.880 number of reasons. Some actually use tunneling as a as 0:09:49.880 --> 0:09:53.560 a food foraging strategy, trying to get underground food. Some 0:09:53.880 --> 0:09:56.679 use it for escaping predators that's a common one, as 0:09:56.679 --> 0:09:59.640 a type of shelter that protects you, and some use 0:09:59.679 --> 0:10:02.920 it for are avoiding the elements in harsh environments. But 0:10:03.400 --> 0:10:06.160 the other half of the equation is that this animal, 0:10:06.320 --> 0:10:09.840 or Rictodromus, was also a cursor, which means a runner. 0:10:09.920 --> 0:10:13.840 Remember the name means digging runner. And the authors of 0:10:13.840 --> 0:10:16.280 this paper say that if we look at analogies today. 0:10:16.440 --> 0:10:19.880 Running animals that create burrows tend to do so for 0:10:19.920 --> 0:10:22.679 a pretty specific reason, which is they create them as 0:10:22.800 --> 0:10:26.280 dens for rearing their young. So once you give birth 0:10:26.360 --> 0:10:30.760 to young, the young and the juveniles are pretty vulnerable 0:10:30.840 --> 0:10:32.880 for a while until they get bigger, big enough to 0:10:33.320 --> 0:10:36.600 run around and defend themselves like an adult can, and 0:10:36.679 --> 0:10:39.800 so a den provides a place to protect the young 0:10:39.880 --> 0:10:43.319 while they're growing and still vulnerable. Now, Joe, you included 0:10:43.360 --> 0:10:46.840 a fabulous bit of paleo art here from this uh 0:10:46.960 --> 0:10:50.160 this study, this is actually in the book as well. Um, 0:10:50.400 --> 0:10:52.120 I love a good bit of paleo art. But here 0:10:52.160 --> 0:10:56.040 we see the parent, we see a cutaway of the burrow, 0:10:56.120 --> 0:10:59.520 and we see the two young dinos at the bottom. 0:10:59.559 --> 0:11:01.760 I like the the paleo artist in this case has 0:11:01.880 --> 0:11:07.320 chosen to depict the adult Erictodromus as Sam the Eagle 0:11:07.440 --> 0:11:11.559 from the Muppets, as a very severe eyebrow and uh 0:11:11.600 --> 0:11:14.959 and and very well. I think this is anatomically accurate 0:11:15.000 --> 0:11:18.040 the beak like mouth. Yes, well, anyway, sorry if that 0:11:18.080 --> 0:11:20.240 was a digression from the paleo burrows, but I just 0:11:20.240 --> 0:11:22.520 wanted to say, yeah, so you're looking at this book 0:11:22.520 --> 0:11:25.760 by Anthony J. Martin. And Martin has a history with 0:11:25.760 --> 0:11:29.720 with the diggers. Yeah, and Martin knows his his tunnels 0:11:29.760 --> 0:11:33.040 and his his burrows here and so he he discusses 0:11:33.120 --> 0:11:37.080 the paleo burrows in the Evolution Underground, pointing out that 0:11:37.640 --> 0:11:42.200 geologists in Argentina and Brazil noted these burrows back in 0:11:42.240 --> 0:11:46.439 the nineteen twenties and nineteen thirties. Uh. Some had partially 0:11:46.679 --> 0:11:50.560 or wholly filled with sediment, but others remained quite open. Uh. 0:11:50.600 --> 0:11:55.719 They were cutting a variety of soft um, igneous, metamorphic, 0:11:55.760 --> 0:11:59.160 and set and sedimentary bedrock. So we're talking about we're 0:11:59.200 --> 0:12:02.720 talking about rock here. That's one of the the important 0:12:02.720 --> 0:12:06.280 and I think really impressive things about about this. Uh. 0:12:06.320 --> 0:12:11.640 Some of some were visible in outcrops, others as cylindrical chambers. 0:12:11.679 --> 0:12:14.240 There are some actually some wonderful photographs you can find 0:12:14.240 --> 0:12:19.079 online and attached to various UM articles about these papers 0:12:19.120 --> 0:12:21.920 about these Uh, they're quite impressive. They look just like 0:12:21.920 --> 0:12:25.640 like a tunnel cut through a rock. You can you 0:12:25.640 --> 0:12:28.160 know that you they look like that. They look like 0:12:28.200 --> 0:12:30.880 real tunnels. We're not just talking about just an indention 0:12:30.920 --> 0:12:32.800 in the side of a hill. Yeah, some of them 0:12:32.840 --> 0:12:36.680 look like somebody brought in the boring machine like a large, 0:12:36.760 --> 0:12:43.520 like several meter wide, basically circular, cylindrical tunnel. Others are smaller, 0:12:43.679 --> 0:12:46.000 more compact, or more kind of a half moon shape. 0:12:46.520 --> 0:12:49.120 But I just wanted to flag this was interesting because 0:12:49.200 --> 0:12:52.640 so Martin notes that the people had previously observed these 0:12:52.679 --> 0:12:57.160 things in the twenties and thirties in Argentina and Brazil. Now, 0:12:57.520 --> 0:13:00.760 I had been reading about the paleo burrows in some 0:13:00.960 --> 0:13:06.480 articles that came out in ten and those articles were 0:13:06.240 --> 0:13:09.640 were essentially saying that that nobody had ever reported these 0:13:09.679 --> 0:13:12.600 things until just recently, that they just sort of come 0:13:12.600 --> 0:13:14.800 on the radar. But it seems like Martin has turned 0:13:14.840 --> 0:13:18.760 up some other previous reports of of these things. Yeah, yeah, 0:13:18.840 --> 0:13:21.160 that that's what seems to be the case. But the 0:13:21.679 --> 0:13:23.920 important thing is that they weren't exactly sure what they 0:13:23.920 --> 0:13:27.080 were looking at here. Now and over the decades to follow, 0:13:27.520 --> 0:13:30.160 hundreds of these caves were uncovered, with a lot of 0:13:30.200 --> 0:13:33.800 concentration in the area of what is now Rio Grande 0:13:34.120 --> 0:13:39.200 do Sol in southern Brazil. Um others other of paleo 0:13:39.240 --> 0:13:42.680 burrows of this nature are simply undiscovered. Uh. I've seen 0:13:42.679 --> 0:13:47.240 a total number express somewhere around like fifteen hundred. And 0:13:47.280 --> 0:13:50.520 again they're likely others as well that haven't been discovered 0:13:50.600 --> 0:13:53.280 or will never be discovered, you know. Yeah, the reporting 0:13:53.280 --> 0:13:56.360 I was reading said that most of these are clustered 0:13:56.440 --> 0:14:00.360 in kind of a kind of strange geographical bands, like 0:14:00.520 --> 0:14:03.800 right in this area in southern Brazil, but not further 0:14:03.920 --> 0:14:07.520 south than like Uruguay. But then if you go even 0:14:07.559 --> 0:14:12.000 further south, there are some more down further into Argentina. Yeah. 0:14:12.120 --> 0:14:14.640 So the archaeologists came back and they were studying them 0:14:14.640 --> 0:14:17.920 with renewed interest in the seventies and eighties, and they 0:14:18.000 --> 0:14:21.880 hypothesized that these were surely the work of human beings. 0:14:22.520 --> 0:14:26.120 Martin writes, quote, considering their proportions and geological setting. This 0:14:26.240 --> 0:14:30.760 was a perfectly reasonable hypothesis, as they superficially resembled human 0:14:30.800 --> 0:14:36.760 made tunnels and chambers in Cappadocia and elsewhere. Now, Cappadocia 0:14:37.600 --> 0:14:41.080 is is noted here, as u is a place that 0:14:41.160 --> 0:14:43.080 in what is modern day Turkey, where you have these 0:14:43.160 --> 0:14:48.360 hit wonderful historic cave houses that can still be seen today. Um, Joe, 0:14:48.440 --> 0:14:51.200 you might be interested to also note that they filmed 0:14:51.240 --> 0:14:54.120 parts of your The Hunter from the future here. Yes, 0:14:54.200 --> 0:14:56.760 there there are quite clear signs of The movie has 0:14:56.800 --> 0:15:00.600 scenes of of the of its muscly superstar, a brown, 0:15:01.680 --> 0:15:05.920 scuttling around over these beautiful rock formations. I think he 0:15:06.000 --> 0:15:15.880 fights a dinosaur in what is clearly Cappadocia than now. 0:15:15.960 --> 0:15:19.080 While some of these paleo burrows, again in South America 0:15:19.760 --> 0:15:22.200 were too small to have served as anything other than 0:15:22.280 --> 0:15:25.840 hiding places for children, um, he writes that others were 0:15:25.960 --> 0:15:29.080 large enough to have potentially been human dwellings. The largest 0:15:29.120 --> 0:15:33.040 were as wide as thirteen feet or four meters um. 0:15:33.080 --> 0:15:36.240 They were six point six feet tall or you know, 0:15:36.240 --> 0:15:39.000 two or two meters, and they were more than three 0:15:39.080 --> 0:15:42.000 hundred and thirty feet long or about a hundred meters 0:15:42.040 --> 0:15:44.280 in length. So again, well, you know, in many of 0:15:44.320 --> 0:15:47.080 these cases, we're not just talking about uh, some sort 0:15:47.120 --> 0:15:51.080 of a narrow burrow, but but something that that that 0:15:51.360 --> 0:15:55.120 that a family or small group could have lived in. Quote. Moreover, 0:15:55.240 --> 0:15:59.040 some tunnels connected with one another or joined larger sub 0:15:59.200 --> 0:16:03.520 spherical chain burrs to make more complicated networks. Once put together, 0:16:03.640 --> 0:16:06.600 some of these spaces feasibly could have served as underground 0:16:06.680 --> 0:16:11.200 homes for families or small communities. A few even contain petroglyphs, 0:16:11.200 --> 0:16:14.880 showing that pre Columbian people entered at least some of them. 0:16:14.920 --> 0:16:17.040 And as we've we've touched on already and know there's 0:16:17.040 --> 0:16:20.280 a there's a long history of humans using naturally occurring caves, 0:16:20.280 --> 0:16:23.240 if not for shelter, then for for other purposes, be 0:16:23.320 --> 0:16:26.160 it like, um, you know, a burial or some sort 0:16:26.200 --> 0:16:29.720 of sacred purpose, or in some cases, you know, we're 0:16:29.720 --> 0:16:32.200 not sure exactly what that purpose might have been. Uh. 0:16:32.240 --> 0:16:36.280 And then we have excellent examples of places like Cappadocia, 0:16:36.320 --> 0:16:40.000 which we just mentioned, which demonstrate that if local geologic 0:16:40.040 --> 0:16:44.400 conditions are conducive to excavation, then homes can be manufactured 0:16:44.440 --> 0:16:47.200 in the substance of the earth. There are also various 0:16:47.200 --> 0:16:52.000 traditions of pit houses partially buried or excavated homes. Again, 0:16:52.000 --> 0:16:54.440 it just kind of depends on the culture what's available 0:16:54.600 --> 0:16:58.280 there in the given environment. But in looking at these 0:16:58.320 --> 0:17:01.760 paleo boroughs, reese ushers begin to notice things that made 0:17:01.800 --> 0:17:06.119 it less likely that humans built these particular tunnels at all. So, 0:17:06.200 --> 0:17:09.840 first of all, while artifacts and petroglyphs did factor into 0:17:09.920 --> 0:17:12.840 some of these sites, we did not find anywhere near 0:17:12.920 --> 0:17:16.120 the amount of human bones and human artifacts that we'd 0:17:16.160 --> 0:17:20.200 expect to find at a place where humans lived, humans visited, 0:17:20.440 --> 0:17:23.040 but they did not seem to live here. And this 0:17:23.119 --> 0:17:25.520 is something that you know, you think of any of 0:17:25.640 --> 0:17:27.640 any of the episodes we've recorded or anything you read 0:17:27.680 --> 0:17:31.720 about about ancient sites of human habitation, you have you know, 0:17:31.760 --> 0:17:34.400 you have these layers you can go through. You can 0:17:34.520 --> 0:17:38.880 you can essentially sort through the garbage of human civilizations 0:17:38.920 --> 0:17:40.760 and learn what they were up to and how long 0:17:40.800 --> 0:17:43.960 they were there. And in these cases, it does not 0:17:44.080 --> 0:17:47.320 seem like there is there are enough artifacts, enough remains 0:17:47.640 --> 0:17:51.680 or even enough you know, um petroglyphs uh to indicate 0:17:51.720 --> 0:17:53.760 that they were here. And that's another thing. Petroglyphic rarity 0:17:53.840 --> 0:17:57.280 in these tunnels indicated, according to Martin quote, folks were 0:17:57.320 --> 0:17:59.840 not inspired enough to hang out in these places. And 0:18:00.280 --> 0:18:04.119 art Another fact, and this gets into the artifact issue 0:18:04.119 --> 0:18:08.840 as well, is indigenous peoples in south eastern South America 0:18:09.119 --> 0:18:11.920 did not have access to the right materials for rock 0:18:11.960 --> 0:18:16.560 carving tools and no evidence of of said tools were found. So, 0:18:16.640 --> 0:18:19.440 again getting back into the that the lack of artifacts 0:18:19.440 --> 0:18:23.400 to support the the idea that humans made these uh, 0:18:23.480 --> 0:18:27.080 these burrows UH and or lived here. So during the 0:18:27.200 --> 0:18:30.160 nine eighties, researchers began to turn their attention away from 0:18:30.240 --> 0:18:33.400 human beings. Uh. They looked at the scale of these 0:18:33.440 --> 0:18:37.400 caves and tunnels. The small child sized tunnels that we mentioned, 0:18:37.640 --> 0:18:41.120 they decided were likely the result of of a smaller 0:18:41.119 --> 0:18:45.840 burrowing prehistoric animals such as giant armadillo. But the grand 0:18:45.920 --> 0:18:48.480 caves and tunnels, the ones in which human families or 0:18:48.520 --> 0:18:52.600 communities could have potentially lived. A new hypothesis emerged for 0:18:52.640 --> 0:18:56.560 these architects, and it's it's not human beings, it's not 0:18:57.400 --> 0:19:01.240 flowing water or you know, natural geologics sees, it is 0:19:01.520 --> 0:19:05.280 the giant ground sloth. The big boys, the big Boys. Yeah, 0:19:05.640 --> 0:19:09.240 so um. I know we've talked about sloths, uh, extant 0:19:09.400 --> 0:19:12.919 sloth species on the show before, and I guess giant 0:19:12.920 --> 0:19:15.040 ground sloths have come up but at least a time 0:19:15.119 --> 0:19:18.159 or two. But I don't think we've really discussed like 0:19:18.240 --> 0:19:22.040 what they were and why they're so cool. Because today 0:19:22.080 --> 0:19:25.399 we have in the world, I believe, six extant species 0:19:25.520 --> 0:19:28.600 of oar boreal sloths. You know, they live in the trees, 0:19:28.640 --> 0:19:32.240 and these are certainly weird and wonderful animals. Um. I'll 0:19:32.240 --> 0:19:33.639 be the first to admit that they can be a 0:19:33.640 --> 0:19:35.520 bit of a bore. If you encounter them in the zoo, 0:19:35.560 --> 0:19:38.399 you know, they're typically just um, you know, bunched in 0:19:38.440 --> 0:19:41.199 the corner of a of an exhibit, you know, just 0:19:41.440 --> 0:19:45.000 chilling or staying warm. Uh. I find that they often 0:19:45.040 --> 0:19:48.400 look like a like a wig hanging on a hook. Yeah. 0:19:48.720 --> 0:19:51.399 And uh, And I mean I'm not commenting on their 0:19:51.480 --> 0:19:54.600 their happiness or lack of happiness there, but they're not 0:19:54.640 --> 0:19:59.000 as interests. They're not magical to behold. But in the wild, uh, 0:19:59.119 --> 0:20:03.399 they come off these two strange elemental spirit beings. I 0:20:03.720 --> 0:20:06.560 had the privilege to glimpse one in the wild ones 0:20:06.600 --> 0:20:08.480 and it was just magical. It's got like this kind 0:20:08.480 --> 0:20:12.280 of thing that like slowly emerges out of the canopy 0:20:12.320 --> 0:20:14.240 and the distance, and you glimpse it for a short 0:20:14.240 --> 0:20:17.840 amount of time and then it's gone. They're also magical 0:20:17.840 --> 0:20:19.520 in a different way if you get up close enough 0:20:19.560 --> 0:20:23.400 to see their face, because they often appear to be smiling. Yes, 0:20:23.480 --> 0:20:28.080 they have very that their faces are in this wonderful 0:20:28.119 --> 0:20:30.960 place that where they You know that we lean into 0:20:31.720 --> 0:20:35.400 anthropomorphizing them rather easily. They look kind of like they're smiling. 0:20:35.440 --> 0:20:38.560 They look a little a little dirty, which is you 0:20:38.600 --> 0:20:43.200 know which which is cute too? Cuteness um and yeah, 0:20:43.280 --> 0:20:46.480 and don't even get it started on baby slots. Absolutely adorable. 0:20:46.920 --> 0:20:50.160 So we have today three toad slots and two toad slots. 0:20:50.720 --> 0:20:53.480 This refers to the four limbs only, and these represent 0:20:53.600 --> 0:20:58.080 two distantly related families that experience convergent evolution to our 0:20:58.160 --> 0:21:02.720 boreal life. Okay, so the sloth lineage is not one 0:21:02.840 --> 0:21:06.199 that that always existed in the trees. The species we 0:21:06.240 --> 0:21:09.679 have today are the ones that happened to move into 0:21:09.760 --> 0:21:12.400 the trees at some point in in in deep history. 0:21:12.920 --> 0:21:16.400 That's right. Yeah, Because plenty of these other slots or 0:21:16.520 --> 0:21:18.840 or slothes if you, if you were rather believe it's 0:21:18.840 --> 0:21:23.760 the British pronounciation. Um, many of them were ground slots, 0:21:23.880 --> 0:21:27.520 and in some cases we're talking giant ground slots. And 0:21:27.560 --> 0:21:32.240 these can be quite impressive. I've enjoyed looking at at bones, 0:21:32.880 --> 0:21:35.840 you know, fossil exhibits of these over time. There's also 0:21:35.880 --> 0:21:41.480 a wonderful, full scale, muddy and shaggy recreation of of 0:21:41.480 --> 0:21:43.840 of a ground slot that Atlanta's own firm Bank Museum 0:21:43.880 --> 0:21:45.919 of Natural History. I don't know if you've been over 0:21:45.960 --> 0:21:48.080 to see this, Joe. But it's in the walk through 0:21:48.119 --> 0:21:51.119 Time in Georgia exhibit. Yeah, I have been through that before, 0:21:51.160 --> 0:21:53.800 though I don't remember exactly what this one looks like. 0:21:53.840 --> 0:21:55.920 I wonder if there's a picture of it online. Hold on, 0:21:56.720 --> 0:22:01.199 Oh yeah, okay, here it is. I remember this now, Okay, 0:22:01.280 --> 0:22:05.160 the sloth needs a bath. First of all, it is filthy. 0:22:05.480 --> 0:22:10.200 It looks really gross. Yeah, it's it's it's it's impressive. 0:22:10.240 --> 0:22:11.680 I imagine it's been I don't know how long it's 0:22:11.680 --> 0:22:13.959 been there, but it has to have been impressing school children, uh, 0:22:14.160 --> 0:22:15.960 for for quite a while at this point. And I 0:22:16.000 --> 0:22:20.760 hope that if at some point they they they change 0:22:20.800 --> 0:22:23.960 anything in that exhibit, they keep the sloth. Uh. This 0:22:24.000 --> 0:22:27.560 would have been a keeping dirty, keep it dirty, keep it, 0:22:28.560 --> 0:22:30.760 keep it, keep it on display. Uh. This would have 0:22:30.920 --> 0:22:34.840 I believe this would have been an airmatherium, which was 0:22:35.200 --> 0:22:37.320 a giant ground slot that would have lived four point 0:22:37.440 --> 0:22:41.440 nine million years ago to around eleven thousand years ago. 0:22:41.920 --> 0:22:44.240 And it was. It was a pretty big big guy, 0:22:44.960 --> 0:22:50.840 rivaling but not surpassing the megatherium in size. Now megatherium, 0:22:50.920 --> 0:22:53.200 this is the This is the biggest of the known 0:22:53.480 --> 0:22:58.320 ground sloths. Of prehistoric times. Uh. Megatherium is Latin for 0:22:58.600 --> 0:23:01.840 the great beast. Oh, I've never put that together before, 0:23:01.880 --> 0:23:04.840 the theory um theoryum being beast, But that would be like, 0:23:05.400 --> 0:23:07.800 as in the word theory amorphic, taking the form of 0:23:07.800 --> 0:23:12.200 a beast. So these guys reached heights of twenty feet 0:23:12.320 --> 0:23:16.000 or six meters, and they probably weighed roughly four tons, uh, 0:23:16.040 --> 0:23:18.919 you know, dealing with the adults here obviously. Um. It 0:23:19.000 --> 0:23:22.919 was simply put the sloth as megafauna fear and feeling 0:23:22.960 --> 0:23:27.080 that filling that niche in the in the ecosystem, a 0:23:27.119 --> 0:23:29.760 giant eating machine that didn't have to worry too much 0:23:29.760 --> 0:23:33.080 about predators, ate a lot to maintain their enormous bodies 0:23:33.119 --> 0:23:35.840