WEBVTT 00:00:00.000 --> 00:00:02.140 I want you to close your eyes for a second. Just 00:00:02.140 --> 00:00:04.320 picture the Caribbean. Oh, that's easy. White 00:00:04.320 --> 00:00:06.620 sand or the turquoise water. Right. Exactly. 00:00:06.900 --> 00:00:10.019 You're probably seeing that pristine travel brochure 00:00:10.019 --> 00:00:13.099 version. Maybe there's a cruise ship docked way 00:00:13.099 --> 00:00:15.000 out in the distance. Someone handing you a very 00:00:15.000 --> 00:00:17.160 colorful drink with a little paper umbrella in 00:00:17.160 --> 00:00:20.260 it. Yeah. Paradise. It is. Well, it's the modern 00:00:20.260 --> 00:00:22.500 definition of paradise, but that's a really surface 00:00:22.500 --> 00:00:24.600 level view of what those islands actually are. 00:00:24.640 --> 00:00:27.219 It really is. Yeah. So let's peel back that layer. 00:00:27.440 --> 00:00:30.460 of the all -inclusive resorts. I wanna zoom in 00:00:30.460 --> 00:00:34.740 specifically on the islands of Antigua and Barbuda. 00:00:34.840 --> 00:00:37.939 Okay, zooming in. And now we're gonna turn the 00:00:37.939 --> 00:00:40.380 clock back. How far back are we talking? Oh, 00:00:40.399 --> 00:00:43.810 way back. We aren't going to the Pirates. or 00:00:43.810 --> 00:00:46.109 even to the arrival of Columbus. Right. We are 00:00:46.109 --> 00:00:48.429 going back thousands of years. Before the very 00:00:48.429 --> 00:00:51.649 first human footstep ever disturbed that white 00:00:51.649 --> 00:00:54.369 sand. Exactly. To a time when those islands were 00:00:54.369 --> 00:00:57.390 louder, wilder, and honestly much stranger than 00:00:57.390 --> 00:00:59.450 they are today. A completely different world. 00:00:59.630 --> 00:01:02.289 In this ancient version of Antigua, there's a 00:01:02.289 --> 00:01:04.290 creature moving through the underbrush. And it 00:01:04.290 --> 00:01:06.810 isn't a bird. It isn't a reptile. Right. Which 00:01:06.810 --> 00:01:08.950 is what you'd expect on a remote island. Right. 00:01:09.150 --> 00:01:12.769 It's a mammal. Yeah. And it is not small. Definitely 00:01:12.769 --> 00:01:14.469 not small. We're talking about something the 00:01:14.469 --> 00:01:17.329 size of a large house cat. Maybe even a small 00:01:17.329 --> 00:01:21.069 dog. It's robust. It's furry. And it is the undisputed 00:01:21.069 --> 00:01:23.989 king of the ground. And here's the real kicker 00:01:23.989 --> 00:01:27.269 about this animal. It survived incredibly long 00:01:27.269 --> 00:01:30.510 odds just to get there. Unbelievable odds. It 00:01:30.510 --> 00:01:33.689 thrived for millennia. And then in the blink 00:01:33.689 --> 00:01:36.969 of a geological eye, it vanished. Poof. Gone. 00:01:37.090 --> 00:01:39.329 But that is not actually the strangest part of 00:01:39.329 --> 00:01:41.469 this whole story. No, the strangest part is its 00:01:41.469 --> 00:01:45.180 current status today. because usually when we 00:01:45.180 --> 00:01:48.000 talk about extinct animals, you know, dinosaurs, 00:01:48.280 --> 00:01:50.579 dodos, the woolly mammoths. We know their names. 00:01:50.739 --> 00:01:52.459 Exactly. We know their names. We have the museum 00:01:52.459 --> 00:01:55.060 t -shirts. We have the lunchboxes. The whole 00:01:55.060 --> 00:01:58.120 branding package. But this creature, you can 00:01:58.120 --> 00:02:01.019 go to a museum right now today. Like the University 00:02:01.019 --> 00:02:03.280 of Florida or the Smithsonian. Yeah, and you 00:02:03.280 --> 00:02:05.959 can literally hold its skull in your hands. We 00:02:05.959 --> 00:02:07.920 have the bones. We have all the measurements. 00:02:07.959 --> 00:02:09.719 We know exactly where it lived, what it ate, 00:02:09.819 --> 00:02:13.319 who ate it. We have so much data. But if you 00:02:13.319 --> 00:02:15.979 open the official rule book of zoology doesn't 00:02:15.979 --> 00:02:19.860 exist it does not it's a biological reality But 00:02:19.860 --> 00:02:24.039 legally it's a taxonomic boast So today we're 00:02:24.039 --> 00:02:26.539 doing a deep dive into this ghost of the Caribbean. 00:02:26.539 --> 00:02:30.039 I love that title a massive extinct rotant that 00:02:30.039 --> 00:02:33.620 is technically completely nameless due to this 00:02:33.620 --> 00:02:36.419 bizarre bureaucratic loophole that has lasted 00:02:36.419 --> 00:02:38.680 for over 60 years. We're talking about the creature 00:02:38.680 --> 00:02:42.180 that is known informally as Echplotomies. Echplotomies. 00:02:42.340 --> 00:02:45.219 Or, as the scientific literature rather coldly 00:02:45.219 --> 00:02:49.639 prefers to call it, Undescribed Species B. Undescribed 00:02:49.639 --> 00:02:51.740 Species B. I mean, that sounds like a vitamin 00:02:51.740 --> 00:02:54.169 supplement, not a giant island conqueror. It 00:02:54.169 --> 00:02:56.169 really lacks a certain grandeur, doesn't it? 00:02:56.270 --> 00:02:58.930 It's a terrible name for a king. It is. But the 00:02:58.930 --> 00:03:01.909 story behind that lack of a name is almost as 00:03:01.909 --> 00:03:04.210 fascinating as the animal itself. For this deep 00:03:04.210 --> 00:03:06.389 dive, we're going to be heavily referencing a 00:03:06.389 --> 00:03:09.250 specific Wikipedia entry that details the taxonomy, 00:03:09.669 --> 00:03:11.669 the morphology, and the history of this creature. 00:03:11.900 --> 00:03:14.659 And that entry is primarily built on the foundational 00:03:14.659 --> 00:03:17.479 work of a paleontologist named Clayton E. Ray. 00:03:17.740 --> 00:03:19.539 Clayton Ray, he's really the central detective 00:03:19.539 --> 00:03:21.879 in this whole mystery. He absolutely is. Okay, 00:03:21.919 --> 00:03:24.120 let's unpack this, because I'm reading the source 00:03:24.120 --> 00:03:25.539 material and it sounds like something out of 00:03:25.539 --> 00:03:27.819 a Kafka novel. It's very bureaucratic. How can 00:03:27.819 --> 00:03:30.199 an animal be sitting in a drawer at Harvard, 00:03:31.199 --> 00:03:33.520 fully fossilized, fully described in writing, 00:03:33.900 --> 00:03:35.699 and yet the scientific community collectively 00:03:35.699 --> 00:03:38.400 says, nope, never heard of it? To really wrap 00:03:38.400 --> 00:03:40.020 your head around that, we have to talk about 00:03:40.020 --> 00:03:43.219 the rules of the game. OK, the rules. Zoology 00:03:43.219 --> 00:03:45.560 isn't just about going out into the field and 00:03:45.560 --> 00:03:47.580 finding cool bones. I mean, that's part of it, 00:03:47.599 --> 00:03:49.860 but it's also about paperwork. Lots of paperwork. 00:03:50.039 --> 00:03:52.560 There is an official governing body called the 00:03:52.560 --> 00:03:56.039 ICZN. Which stands for? The International Commission 00:03:56.039 --> 00:03:59.379 on Zoological Nomenclature. Wow. Yeah, they are 00:03:59.379 --> 00:04:01.939 basically the Supreme Court of Animal Names. 00:04:02.080 --> 00:04:05.120 The Supreme Court of Taxonomy. I imagine their 00:04:05.120 --> 00:04:08.120 meetings are very lively. They are incredibly 00:04:08.120 --> 00:04:10.560 precise, let's put it that way. But they have 00:04:10.560 --> 00:04:14.479 to be. Their job is to prevent total chaos. Think 00:04:14.479 --> 00:04:17.220 about it. If we didn't have strict universal 00:04:17.220 --> 00:04:20.500 rules, you'd have, say, five different scientists 00:04:20.500 --> 00:04:23.300 discovering the exact same species of beetle 00:04:23.300 --> 00:04:25.500 on five different expeditions. Then they'd all 00:04:25.500 --> 00:04:27.939 give it a different name. Exactly. You'd have 00:04:27.939 --> 00:04:30.420 five different names in the literature, and no 00:04:30.420 --> 00:04:32.079 one would know that they were all talking about 00:04:32.079 --> 00:04:35.170 the same bug. science would grind to a halt. 00:04:35.529 --> 00:04:38.430 Okay, so I get why the ICZN exists. They need 00:04:38.430 --> 00:04:41.470 a strict code on what counts as a legally published 00:04:41.470 --> 00:04:43.709 name so everyone is on the same page. Right. 00:04:44.050 --> 00:04:46.310 And that brings us to Clayton Ray. Enter our 00:04:46.310 --> 00:04:50.199 detective. So rewind the clock to 1962. Clayton 00:04:50.199 --> 00:04:53.160 Ray is a PhD student at Harvard University, and 00:04:53.160 --> 00:04:55.860 he's writing his thesis on the rodents of the 00:04:55.860 --> 00:04:58.699 Antilles. The Caribbean islands. Yes. He's examining 00:04:58.699 --> 00:05:01.420 these subfossil and fossil collections from Antigua 00:05:01.420 --> 00:05:04.139 and Barbuda. And as he's looking at these bones, 00:05:04.259 --> 00:05:06.579 he realizes he's holding something entirely new. 00:05:06.740 --> 00:05:09.319 It's not just another rat. No, this is a monster 00:05:09.319 --> 00:05:11.319 rat. It's totally distinct from anything else 00:05:11.319 --> 00:05:13.399 on record. So he does what a good scientist does. 00:05:13.620 --> 00:05:16.180 He does the work. He does a brilliant job, actually. 00:05:16.560 --> 00:05:19.339 He measures the skulls. He painstakingly describes 00:05:19.339 --> 00:05:23.100 the teeth, the morphology. He figures out exactly 00:05:23.100 --> 00:05:25.920 where this giant fits in the mammalian family 00:05:25.920 --> 00:05:28.439 tree. He maps it all out? He maps it out, and 00:05:28.439 --> 00:05:31.560 he names it. He gives it the species name, Orizomis 00:05:31.560 --> 00:05:34.529 hypoidemus. Orizomis hypoidemus. And he even 00:05:34.529 --> 00:05:37.509 creates a brand new subgenus for it, which he 00:05:37.509 --> 00:05:40.329 calls ecblutimus. So he typed this all up. He 00:05:40.329 --> 00:05:42.410 types it all up, gets it bound into his thesis, 00:05:42.649 --> 00:05:44.589 and he submits it to the faculty at Harvard. 00:05:44.689 --> 00:05:47.370 He defends it, gets his PhD. He gets his doctorate. 00:05:47.569 --> 00:05:50.110 And that physical thesis document goes right 00:05:50.110 --> 00:05:52.449 into the Harvard Library archives. OK, so case 00:05:52.449 --> 00:05:55.079 closed, right? The giant rat. has a name. It's 00:05:55.079 --> 00:05:56.839 written down at Harvard. You would really think 00:05:56.839 --> 00:05:59.319 so. But here is the massive loophole. I'm bracing 00:05:59.319 --> 00:06:01.920 myself. According to the International Code of 00:06:01.920 --> 00:06:04.720 Zoological Nomenclature. The Supreme Court. Right. 00:06:05.519 --> 00:06:07.779 According to their rules, a universe of thesis, 00:06:08.240 --> 00:06:12.040 especially one from 1962, is not legally considered 00:06:12.040 --> 00:06:14.199 a published work. Wait, hold on. It's sitting 00:06:14.199 --> 00:06:16.980 in the Harvard Library. Yes. Any researcher can 00:06:16.980 --> 00:06:19.899 walk in, request it, and read it. They can. Other 00:06:19.899 --> 00:06:22.279 scientists have literally cited it in their own 00:06:22.279 --> 00:06:25.100 papers. How was that not considered published? 00:06:25.319 --> 00:06:27.180 It all comes down to their strict definition 00:06:27.180 --> 00:06:30.019 of public dissemination. Public dissemination. 00:06:30.199 --> 00:06:33.120 The ICZN logic is that a thesis is essentially 00:06:33.120 --> 00:06:36.519 an internal academic document. It's a final exam 00:06:36.519 --> 00:06:39.480 for a student. An incredibly long final exam. 00:06:39.660 --> 00:06:42.899 Exactly. But it wasn't printed in a recognized 00:06:42.899 --> 00:06:46.300 scientific journal. It wasn't distributed to 00:06:46.300 --> 00:06:49.079 thousands of libraries and universities globally. 00:06:49.160 --> 00:06:51.279 It wasn't put out for the mass scientific public. 00:06:51.420 --> 00:06:54.199 Right. In the legal taxonomic sense, it wasn't 00:06:54.199 --> 00:06:56.839 made formally available. So because he didn't 00:06:56.839 --> 00:06:59.730 take that specific cha... of his thesis and mail 00:06:59.730 --> 00:07:02.709 it off to Nature or Science or the Journal of 00:07:02.709 --> 00:07:05.029 Paleontology. The names don't count. That is 00:07:05.029 --> 00:07:07.689 wild. Because he never formally published that 00:07:07.689 --> 00:07:09.810 exact taxonomic description in a wide -release 00:07:09.810 --> 00:07:14.329 format, the names Orizames, Hypememus, and Echblitemes 00:07:14.329 --> 00:07:17.629 are legally considered unavailable names. Unavailable. 00:07:17.730 --> 00:07:19.410 It's like a squatter. It's living in the house 00:07:19.410 --> 00:07:21.269 of taxonomy. Everyone knows it's there, but it 00:07:21.269 --> 00:07:22.850 doesn't actually have the deed to the property. 00:07:23.250 --> 00:07:26.529 That seems... I mean, I get the need for rules, 00:07:26.610 --> 00:07:28.850 but that just seems incredibly pedantic. It's 00:07:28.850 --> 00:07:31.350 deeply pedantic. We've known about this animal 00:07:31.350 --> 00:07:35.310 and its proposed name for over 60 years. Everyone 00:07:35.310 --> 00:07:37.920 in the field knows what eculotomies is. They 00:07:37.920 --> 00:07:41.379 do, but science relies on that pedantry to function 00:07:41.379 --> 00:07:43.980 consistently across centuries and across language 00:07:43.980 --> 00:07:46.899 barriers. I suppose. But you're right, it does 00:07:46.899 --> 00:07:49.199 leave us in this weird, frustrating limbo where 00:07:49.199 --> 00:07:51.379 we essentially have to use the name in quotation 00:07:51.379 --> 00:07:53.540 marks. Which is why we're calling it a ghost 00:07:53.540 --> 00:07:56.779 species. Exactly. It's fully visible to anyone 00:07:56.779 --> 00:08:00.279 who opens the drawer, but legally, on paper, 00:08:00.680 --> 00:08:03.079 it's invisible. Well, ghost or not, I really 00:08:03.079 --> 00:08:05.220 want to talk about the name that Clayton Ray 00:08:05.220 --> 00:08:07.399 tried to give it. We should. Because usually 00:08:07.399 --> 00:08:09.060 when you read scientific names, they're just 00:08:09.060 --> 00:08:11.899 dry Latin descriptors, right? Like largefoot 00:08:11.899 --> 00:08:14.319 or redhead. They're very literal. But Ray got 00:08:14.319 --> 00:08:16.379 surprisingly poetic with this one. He really 00:08:16.379 --> 00:08:18.860 did. He wasn't just describing bones. He was 00:08:18.860 --> 00:08:21.339 telling a story with the etymology. Let's break 00:08:21.339 --> 00:08:23.540 that down. Start with this species name. OK. 00:08:23.740 --> 00:08:27.100 The species name is Hypenemus. Hypenemus. Which 00:08:27.100 --> 00:08:29.740 means what, exactly? It derives from the ancient 00:08:29.740 --> 00:08:33.100 Greek word Hypanemos. Okay. And that translates 00:08:33.100 --> 00:08:35.759 directly to Leeward. Leeward? As in the Leeward 00:08:35.759 --> 00:08:39.379 Islands? Exactly. Geographically, Antigua and 00:08:39.379 --> 00:08:41.600 Barbuda are part of the Leeward Islands chain 00:08:41.600 --> 00:08:44.100 in the West Indies. So he's anchoring the animal 00:08:44.100 --> 00:08:46.200 to its physical home right there in the name. 00:08:46.379 --> 00:08:49.379 That's right. But the subgenus name, ekbletomys, 00:08:49.440 --> 00:08:51.600 that's the one that really paints a vivid picture. 00:08:52.159 --> 00:08:54.179 Ekbletomys. It's a portmanteau, right? It is. 00:08:54.200 --> 00:08:57.279 It's a combination of two Greek words, ekbletos 00:08:57.279 --> 00:09:00.440 and phlos. OK. Well, I know moos is the standard 00:09:00.440 --> 00:09:03.600 root for mouse. Right. What is ekbletos? Ekbletos 00:09:03.600 --> 00:09:07.080 means cast up or thrown out. Cast up. So put 00:09:07.080 --> 00:09:10.120 it together. The cast up mouse. The cast up mouse. 00:09:10.200 --> 00:09:13.039 That is so evocative. I mean, the cast up mouse, 00:09:13.320 --> 00:09:15.960 it immediately makes me think of a shipwreck 00:09:15.960 --> 00:09:18.509 or a a survivor washing ashore on a piece of 00:09:18.509 --> 00:09:20.850 driftwood. Which is precisely what Ray intended 00:09:20.850 --> 00:09:23.629 when he chose it. Really? Yes. He chose that 00:09:23.629 --> 00:09:26.549 specific imagery because it hints at a very specific 00:09:26.549 --> 00:09:29.690 scientific theory, the rafting theory. The idea 00:09:29.690 --> 00:09:32.110 that this animal didn't just walk across a land 00:09:32.110 --> 00:09:35.049 bridge to get to Antigua... No, it was washed 00:09:35.049 --> 00:09:38.090 ashore. It was a literal castaway. We are definitely 00:09:38.090 --> 00:09:39.769 going to get into the details of that voyage. 00:09:40.169 --> 00:09:42.429 The source material calls it a Sinbad voyage, 00:09:42.649 --> 00:09:45.580 which is... Just a fantastic phrase. It's an 00:09:45.580 --> 00:09:48.080 epic journey. But before we send our giant rat 00:09:48.080 --> 00:09:50.740 out to sea, I think we need to get a much better 00:09:50.740 --> 00:09:52.659 handle on what this animal actually looked like. 00:09:52.799 --> 00:09:55.159 Physically, you mean? Yeah, structurally. Because 00:09:55.159 --> 00:09:57.419 earlier you said it was the size of a large house 00:09:57.419 --> 00:09:59.860 cat. Give or take, yes. But when I say the words 00:09:59.860 --> 00:10:03.080 rat or mouse to you, I think most people, myself 00:10:03.080 --> 00:10:06.139 included, have very specific ingrained image. 00:10:06.299 --> 00:10:09.429 Sure. We picture a subway rat. We'd picture a 00:10:09.429 --> 00:10:12.429 pest, something small, skittish, darting along 00:10:12.429 --> 00:10:14.370 a baseboard. Right, and you need to completely 00:10:14.370 --> 00:10:17.090 erase that image from your mind for this. Erasing. 00:10:17.190 --> 00:10:20.509 This is not a subway rat. Echblutomys belongs 00:10:20.509 --> 00:10:23.750 to a group known as the orizomenes. Orizomenes? 00:10:23.909 --> 00:10:26.029 The common name for that group is the rice rats. 00:10:26.169 --> 00:10:28.990 Okay. But even within the rice rats, Echblutomys 00:10:28.990 --> 00:10:31.769 was an absolute giant. So in the world of Caribbean 00:10:31.769 --> 00:10:35.269 rodents, this was basically megafauna. It was. 00:10:35.330 --> 00:10:37.769 It was the largest known orizomene. How big is 00:10:37.769 --> 00:10:39.710 megafauna when we're talking about a rat? Give 00:10:39.710 --> 00:10:42.750 us a comparison. We often compare its scale to 00:10:42.750 --> 00:10:46.009 another famous extinct Caribbean giant called 00:10:46.009 --> 00:10:50.129 Megalomys dysmoresti. Megalomies, mega mouse. 00:10:50.649 --> 00:10:54.250 Exactly. These animals were incredibly robust. 00:10:54.389 --> 00:10:56.269 We are talking about a body length that could 00:10:56.269 --> 00:10:59.509 potentially be over a foot long. And that's not 00:10:59.509 --> 00:11:02.370 even counting a very long, thick tail. Wow. They 00:11:02.370 --> 00:11:05.710 were heavy, muscular creatures. If you saw one 00:11:05.710 --> 00:11:07.830 of these walking around today, your brain wouldn't 00:11:07.830 --> 00:11:10.610 immediately register, eek, a mouse. Oh, what 00:11:10.610 --> 00:11:11.950 would I think? You'd probably think, is that 00:11:11.950 --> 00:11:15.590 a beaver? Or maybe a huge muskrat? It had real 00:11:15.590 --> 00:11:17.850 physical presence. It had undeniable presence, 00:11:17.870 --> 00:11:19.970 and we know this because of the skull. The source 00:11:19.970 --> 00:11:22.049 material goes into a ton of detail about the 00:11:22.049 --> 00:11:24.830 exact skull measurements, millimeters and ratios. 00:11:24.929 --> 00:11:28.110 It gets very granular. And I know usually when 00:11:28.110 --> 00:11:29.990 we start reading off millimeter measurements 00:11:29.990 --> 00:11:32.809 of old bones, people's eyes tend to glaze over 00:11:32.809 --> 00:11:34.649 a bit. Oh, absolutely. It sounds like dry data. 00:11:35.029 --> 00:11:37.529 But in this case, those specific bone measurements 00:11:37.529 --> 00:11:40.779 are everything, right? They're the only way we 00:11:40.779 --> 00:11:43.039 know for sure that this isn't just the exact 00:11:43.039 --> 00:11:45.080 same rat they found on the next island over. 00:11:45.340 --> 00:11:47.899 That is the critical point. That's why the measurements 00:11:47.899 --> 00:11:50.879 matter so much. Explain that. See, the Caribbean 00:11:50.879 --> 00:11:53.460 historically had a few of these giant rats. We 00:11:53.460 --> 00:11:55.559 mentioned megalomies, which lived on islands 00:11:55.559 --> 00:11:58.580 like Martinique. So if you're a slightly lazy 00:11:58.580 --> 00:12:01.179 scientist back in the day looking at a drawer 00:12:01.179 --> 00:12:04.639 of big bones from Antigua, it would be very easy 00:12:04.639 --> 00:12:07.970 to just shrug and say, eh, they're all just big 00:12:07.970 --> 00:12:10.230 rats. They're all the same basic thing. Right. 00:12:10.490 --> 00:12:13.590 Big rat A on Martinique, big rat B on Antigua, 00:12:14.009 --> 00:12:16.110 probably the same species they just swam across. 00:12:16.529 --> 00:12:19.450 But Ray didn't do that. Ray looked closer. He 00:12:19.450 --> 00:12:22.009 looked at the holotype skull of Eclitmus, the 00:12:22.009 --> 00:12:24.889 primary reference specimen, and he saw something 00:12:24.889 --> 00:12:27.809 fundamentally structurally different from megalomus. 00:12:28.009 --> 00:12:30.330 What did he see? He zeroed in on something called 00:12:30.330 --> 00:12:33.129 the interorbital region. Okay, let's help everyone 00:12:33.129 --> 00:12:36.529 visualize this. Where exactly is the interorbital 00:12:36.529 --> 00:12:38.730 region on a skull? Okay, put your fingers on 00:12:38.730 --> 00:12:40.710 your own temples. Right, fingers on temples. 00:12:41.169 --> 00:12:43.590 Right between your eyes and your ears, that bridge 00:12:43.590 --> 00:12:46.070 of bone that sits just behind the eye sockets. 00:12:46.970 --> 00:12:49.740 I feel it. In most animals, and notably in the 00:12:49.740 --> 00:12:52.740 neighboring giant megalomus, this area is quite 00:12:52.740 --> 00:12:56.720 broad. It's wide. Yes. It forms a wide, sturdy 00:12:56.720 --> 00:13:00.240 highway of bone connecting the face to the main 00:13:00.240 --> 00:13:03.480 brain case. It's a wide forehead. Exactly. But 00:13:03.480 --> 00:13:06.259 when Ray examined a cabal de mace, he found that 00:13:06.259 --> 00:13:09.100 this exact space is aggressively constricted. 00:13:09.399 --> 00:13:11.960 Constricted how? It is severely pinched inward. 00:13:12.379 --> 00:13:15.480 In fact, it is narrower than in any other rice 00:13:15.480 --> 00:13:17.759 rat known to science. Pinched like he was put 00:13:17.759 --> 00:13:20.019 in a vice grip? Morphologically speaking, yes. 00:13:20.500 --> 00:13:22.240 Imagine looking at the top of the skull and it 00:13:22.240 --> 00:13:24.480 looks like an hourglass. OK, I see that. The 00:13:24.480 --> 00:13:26.360 waist of that hourglass right between the eyes 00:13:26.360 --> 00:13:29.110 is incredibly thin. That's the defining feature 00:13:29.110 --> 00:13:31.549 of the skull roof of egg boltomies. But why does 00:13:31.549 --> 00:13:33.889 that matter? I mean, is it just a cosmetic quirk? 00:13:34.110 --> 00:13:36.110 Just a case of, oh, well, this family has a narrow 00:13:36.110 --> 00:13:38.610 face. No, not at all. In biology, especially 00:13:38.610 --> 00:13:41.690 in functional anatomy, form always follows function. 00:13:41.870 --> 00:13:45.110 OK. That specific part of the skull, that interorbital 00:13:45.110 --> 00:13:47.309 region, is where the temporal muscles attach. 00:13:47.690 --> 00:13:49.629 The temporal muscles. Those are for chewing. 00:13:50.029 --> 00:13:52.730 Yes. Those are the big, powerful muscles that 00:13:52.730 --> 00:13:54.909 control the closing of the jaw. Oh, interesting. 00:13:55.120 --> 00:13:57.559 So when you change the architecture of that skull 00:13:57.559 --> 00:14:00.600 roof so drastically when you pinch it in, you 00:14:00.600 --> 00:14:03.340 are fundamentally changing the leverage and the 00:14:03.340 --> 00:14:05.980 structural integrity of the entire head. You're 00:14:05.980 --> 00:14:08.200 changing how the machine works. Exactly. You 00:14:08.200 --> 00:14:10.659 changed the bite force. So this narrow skull 00:14:10.659 --> 00:14:13.460 implies that Ekbultemes was eating differently 00:14:13.460 --> 00:14:16.379 than its neighbors, using its mouth in a totally 00:14:16.379 --> 00:14:19.899 different way. It strongly implies a deep evolutionary 00:14:19.899 --> 00:14:22.779 divergence in their diet and behavior, you don't 00:14:22.779 --> 00:14:25.120 just develop a heavily pinched skull overnight. 00:14:25.279 --> 00:14:27.840 It takes time. That kind of major structural 00:14:27.840 --> 00:14:30.980 redesign takes hundreds of thousands, maybe millions 00:14:30.980 --> 00:14:33.700 of years of complete genetic separation. Wow. 00:14:34.120 --> 00:14:36.460 So that narrow hourglass shape proves beyond 00:14:36.460 --> 00:14:38.919 a doubt that Ekbultemes isn't just a megalomys 00:14:38.919 --> 00:14:41.299 that decided to move to Antigua. It's not a cousin 00:14:41.299 --> 00:14:44.039 who just hopped a fairy. No, it represents a 00:14:44.039 --> 00:14:46.320 completely separate lineage, a totally different 00:14:46.320 --> 00:14:48.519 branch of the family tree that just happened 00:14:48.519 --> 00:14:50.720 to end up in the same geographical neighborhood? 00:14:51.120 --> 00:14:53.759 That is fascinating. And there's another detail 00:14:53.759 --> 00:14:55.759 about the mouth architecture in the source material 00:14:55.759 --> 00:14:59.220 that really stood out to me. The palate. Or the 00:14:59.220 --> 00:15:01.820 teeth. Well, both really. Yeah. The palate is 00:15:01.820 --> 00:15:04.220 described as being very short, barely extending 00:15:04.220 --> 00:15:06.679 past the third molar. Right. And the insides 00:15:06.679 --> 00:15:08.399 of the foramina, which are those holes in the 00:15:08.399 --> 00:15:10.559 roof of the mouth, are also extremely short. 00:15:10.820 --> 00:15:13.580 Yes, very compact. But the teeth are what really 00:15:13.580 --> 00:15:16.440 caught my eye. The text says it had massive molars 00:15:16.440 --> 00:15:20.360 but slender incisors. Yes. The dental profile 00:15:20.360 --> 00:15:23.000 is incredibly telling. So translate that for 00:15:23.000 --> 00:15:26.000 us. What does having huge back teeth but skinny 00:15:26.000 --> 00:15:28.100 front teeth actually tell us about what this 00:15:28.100 --> 00:15:30.759 giant rat was doing for dinner? Think about teeth 00:15:30.759 --> 00:15:34.460 as tools in a toolbox. Okay. If you have huge 00:15:34.460 --> 00:15:37.059 heavy complex grinding molars in the back of 00:15:37.059 --> 00:15:39.480 your mouth, you are built to process something 00:15:39.480 --> 00:15:42.710 tough. Like what? Maybe... coarse fibrous island 00:15:42.710 --> 00:15:46.090 vegetation, maybe really hard seeds. You are 00:15:46.090 --> 00:15:48.409 an anatomical grinder. The grinder. But then 00:15:48.409 --> 00:15:50.789 look at the incisors, the front biting teeth. 00:15:51.070 --> 00:15:53.929 They are slender, relatively delicate for an 00:15:53.929 --> 00:15:56.889 animal this size. Now, compare that toolbox to 00:15:56.889 --> 00:16:01.370 the neighbor, megalomies. Megalomies had noticeably 00:16:01.370 --> 00:16:04.990 smaller molars, but absolutely massive, thick, 00:16:05.470 --> 00:16:08.870 robust front incisors. So megalomies was using 00:16:08.870 --> 00:16:12.899 its front teeth. as the primary tool. Yes. Megalomies 00:16:12.899 --> 00:16:14.919 might have been cracking up in really hard nuts 00:16:14.919 --> 00:16:18.220 or gnawing through tough wood using those big 00:16:18.220 --> 00:16:20.950 front teeth almost like chisels. So Megalomys 00:16:20.950 --> 00:16:24.110 is a cracker, and Iqblotemis is a grinder. Exactly. 00:16:24.570 --> 00:16:26.370 And this tells us that even though they were 00:16:26.370 --> 00:16:29.289 both giant rats living on Caribbean islands relatively 00:16:29.289 --> 00:16:31.529 close to each other, they had evolved to fill 00:16:31.529 --> 00:16:33.909 completely different ecological niches. They 00:16:33.909 --> 00:16:36.409 weren't just carbon copies of the same survival 00:16:36.409 --> 00:16:39.129 strategy. Not at all. It really emphasizes the 00:16:39.129 --> 00:16:41.250 idea that the Caribbean wasn't just this generic 00:16:41.250 --> 00:16:43.730 uniform basket of tropical islands. Each island 00:16:43.730 --> 00:16:47.110 was its own world. Each one was a unique, isolated 00:16:47.110 --> 00:16:50.019 laboratory of evolution. Laboratory is the perfect 00:16:50.019 --> 00:16:52.700 word for it. Isolation is what breeds biological 00:16:52.700 --> 00:16:54.659 innovation. Because there's no gene flow from 00:16:54.659 --> 00:16:56.639 the outside. Right. When you stick a small animal 00:16:56.639 --> 00:16:58.559 on a remote island and just leave it completely 00:16:58.559 --> 00:17:01.139 alone for a million years, it starts to get weird. 00:17:01.179 --> 00:17:04.319 It has to. It solves the basic problems of survival 00:17:04.319 --> 00:17:08.519 in highly unique, localized ways. Atblitomies 00:17:08.519 --> 00:17:11.039 solved the problem of surviving on ancient Antigua 00:17:11.039 --> 00:17:13.819 by becoming a massive, narrow -skulled grinding 00:17:13.819 --> 00:17:16.799 machine. But to become a weird islander, you 00:17:16.799 --> 00:17:19.839 first have to actually get to the island. Ah, 00:17:20.140 --> 00:17:23.420 yes, the hardest part. Which brings us to section 00:17:23.420 --> 00:17:27.839 three of our outline, The Voyage. The Sinbad 00:17:27.839 --> 00:17:30.000 Voyage. I just love that Clayton Rae used that 00:17:30.000 --> 00:17:32.480 specific comparison, because if you pull up a 00:17:32.480 --> 00:17:36.009 map, Antigua and Barbuda are, well... they are 00:17:36.009 --> 00:17:38.490 not close to South America. They are deeply isolated. 00:17:38.609 --> 00:17:40.849 They're way up the northern end of the Lesser 00:17:40.849 --> 00:17:42.789 Antilles chain. To get there from the mainland 00:17:42.789 --> 00:17:45.450 coast to South America, you have to cross a tremendous 00:17:45.450 --> 00:17:48.829 amount of open ocean. So, logically, the most 00:17:48.829 --> 00:17:50.670 obvious theory for how a rat gets there would 00:17:50.670 --> 00:17:52.490 be island hopping, right? Like stepping stones 00:17:52.490 --> 00:17:55.890 across a pond. Yeah. You swim or drift a short 00:17:55.890 --> 00:17:58.269 distance from Venezuela to Trinidad, then you 00:17:58.269 --> 00:18:00.410 establish a population there, then maybe a few 00:18:00.410 --> 00:18:02.509 generations later, some wash over to Grenada. 00:18:02.720 --> 00:18:05.880 Then St. Vincent, St. Lucia, Martinique, Dominica, 00:18:06.099 --> 00:18:07.779 Guadalupe. Right, just working your way up the 00:18:07.779 --> 00:18:10.339 chain, island by island, over thousands of years. 00:18:10.480 --> 00:18:12.900 That is the intuitive theory. It feels logical 00:18:12.900 --> 00:18:15.740 and safe. But Ray totally rejected that idea 00:18:15.740 --> 00:18:18.559 for ectyltomize. He did. He looked at the data 00:18:18.559 --> 00:18:21.579 and said, no, that's not what happened. Why? 00:18:22.000 --> 00:18:24.339 I mean, taking it in short hops seems infinitely 00:18:24.339 --> 00:18:27.200 easier than doing it in one massive shot. Ray 00:18:27.200 --> 00:18:29.920 looked closely at the geology and the bathymetry. 00:18:30.329 --> 00:18:33.670 the ocean depth of the region, even during the 00:18:33.670 --> 00:18:36.910 Pleistocene Epoch, the Ice Age, when global sea 00:18:36.910 --> 00:18:39.509 levels were drastically lower because so much 00:18:39.509 --> 00:18:41.930 water was locked up in the polar ice caps. The 00:18:41.930 --> 00:18:43.730 islands would have been bigger then, right? More 00:18:43.730 --> 00:18:46.730 exposed land? They were larger, yes. But the 00:18:46.730 --> 00:18:49.589 deep ocean channels between those islands, those 00:18:49.589 --> 00:18:52.609 remained. They were still massive, turbulent 00:18:52.609 --> 00:18:55.109 water barriers. So it wasn't a land bridge situation? 00:18:55.210 --> 00:18:57.839 Not at all. Ray calculated that to get from the 00:18:57.839 --> 00:19:00.259 South American mainland all the way up to Barbuda 00:19:00.259 --> 00:19:03.799 by hopping, this specific lineage of a rat would 00:19:03.799 --> 00:19:07.319 have to successfully cross at least seven distinct 00:19:07.319 --> 00:19:10.420 deep water ocean barriers. Seven times they'd 00:19:10.420 --> 00:19:13.339 have to brave the open ocean and win. Seven consecutive 00:19:13.339 --> 00:19:15.900 miracles. You have to launch a few individuals 00:19:15.900 --> 00:19:18.259 into the water. They have to land safely on the 00:19:18.259 --> 00:19:21.839 next island. establish a viable colony, thrive 00:19:21.839 --> 00:19:24.420 there, outcompete whatever's already living there. 00:19:24.559 --> 00:19:26.539 And then eventually launch another population 00:19:26.539 --> 00:19:28.940 into the water to the next island. Right. And 00:19:28.940 --> 00:19:30.759 Ray argued that the mathematical probability 00:19:30.759 --> 00:19:33.819 of doing that seven times in a row, and crucially, 00:19:34.019 --> 00:19:36.700 without leaving any fossil trace of this specific 00:19:36.700 --> 00:19:38.799 lineage on the intermediate island. Because we 00:19:38.799 --> 00:19:42.079 don't find Ichblochemies on Grenada or St. Vincent. 00:19:42.240 --> 00:19:45.160 Exactly. To do all that without leaving a trace 00:19:45.160 --> 00:19:47.880 is statistically, practically impossible. So 00:19:47.880 --> 00:19:50.190 that's where the quote comes from. Yes. Ray wrote 00:19:50.190 --> 00:19:52.670 that a series of successful sequential voyages 00:19:52.670 --> 00:19:55.450 like that would be, quote, no less wondrous than 00:19:55.450 --> 00:19:58.069 those of Sinbad. So if they didn't hop from island 00:19:58.069 --> 00:20:01.089 to island, they must have. rafted in one straight 00:20:01.089 --> 00:20:03.829 shot. The rafting theory, also known in biogeography 00:20:03.829 --> 00:20:06.250 as the sweepstakes route. Sweepstakes route. 00:20:06.529 --> 00:20:08.450 That name implies that most people who enter 00:20:08.450 --> 00:20:11.130 the sweepstakes lose. Almost everyone loses. 00:20:11.650 --> 00:20:14.009 A sweepstakes route is a high stakes, extremely 00:20:14.009 --> 00:20:16.650 low probability dispersal event. Okay, I need 00:20:16.650 --> 00:20:18.569 you to really paint the picture for us here. 00:20:18.750 --> 00:20:21.950 Because when you say rafting rat, my brain immediately 00:20:21.950 --> 00:20:24.450 goes to a cartoon. Like a rat tying some twigs 00:20:24.450 --> 00:20:26.349 together with vines and raising a little leaf 00:20:26.349 --> 00:20:28.569 sail? Exactly. Stuart Little on the high season. 00:20:28.799 --> 00:20:32.759 What is a natural raft actually like? OK, you 00:20:32.759 --> 00:20:36.599 have to picture the great massive river systems 00:20:36.599 --> 00:20:39.039 of the South American continent. Like the Orinoco 00:20:39.039 --> 00:20:43.519 or the Amazon. Exactly. Imagine a massive catastrophic 00:20:43.519 --> 00:20:47.799 storm, a huge hurricane system, or maybe just 00:20:47.799 --> 00:20:50.180 unprecedented seasonal flooding high up in the 00:20:50.180 --> 00:20:52.140 mountains or the rainforest. The water levels 00:20:52.140 --> 00:20:55.079 rise rapidly. The river swells enormously. It 00:20:55.079 --> 00:20:56.960 becomes a torrent and it starts undercutting 00:20:56.960 --> 00:21:00.019 its own muddy bank. And the land just collapses 00:21:00.019 --> 00:21:02.960 into the churning water. Huge intact chunks of 00:21:02.960 --> 00:21:05.240 the forest floor. We are talking about dense 00:21:05.240 --> 00:21:07.900 mats of vegetation, tightly interlocked tree 00:21:07.900 --> 00:21:10.759 roots, fallen trunks, vines, thick soil. Like 00:21:10.759 --> 00:21:13.240 floating islands of dirt and wood. Yes. Some 00:21:13.240 --> 00:21:14.920 might be the size of living room. Some might 00:21:14.920 --> 00:21:16.940 be the size of a whole house or even larger. 00:21:17.039 --> 00:21:19.940 Wow. These massive mats float rapidly down the 00:21:19.940 --> 00:21:21.980 swollen river and eventually get blasted right 00:21:21.980 --> 00:21:25.579 out into the ocean. And if our little rat ancestor 00:21:25.579 --> 00:21:27.460 just happened to be sitting on that particular 00:21:27.460 --> 00:21:29.900 piece of land when it gave way. There's suddenly 00:21:29.900 --> 00:21:32.539 a passenger on an ocean voyage. And I'm guessing 00:21:32.539 --> 00:21:35.160 this is not a luxury cruise. It is an absolute 00:21:35.160 --> 00:21:37.839 nightmare. I can't even imagine. You are drifting 00:21:37.839 --> 00:21:40.579 helplessly in the strong Caribbean currents. 00:21:41.140 --> 00:21:43.619 The sun is beating down on you relentlessly. 00:21:43.859 --> 00:21:47.140 Tropical sun. No canopy cover. No shade. And 00:21:47.140 --> 00:21:49.960 worse, you have absolutely no fresh water. Just 00:21:49.960 --> 00:21:52.519 whatever rain happens to fall. Right. You are 00:21:52.519 --> 00:21:55.779 constantly battered by salt spray, which is dehydrating 00:21:55.779 --> 00:21:58.539 you further. You have to endure ocean storms 00:21:58.539 --> 00:22:00.859 that are actively trying to break your fragile 00:22:00.859 --> 00:22:04.000 raft apart. And you have to survive this horrific 00:22:04.000 --> 00:22:07.980 ordeal for, realistically, how long? To drift 00:22:07.980 --> 00:22:09.980 from the mouth of the Orinoco all the way up 00:22:09.980 --> 00:22:12.400 to the Leeward Islands, you are looking at weeks. 00:22:12.539 --> 00:22:15.220 Weeks? Maybe even a full month at sea. A month 00:22:15.220 --> 00:22:17.319 on a floating tangle of roots with no water. 00:22:17.400 --> 00:22:20.420 And here is the truly crucial mind -bending part 00:22:20.420 --> 00:22:23.900 of the sweepstakes. It cannot just be one tough 00:22:23.900 --> 00:22:26.680 male rat that survives this. Because one male 00:22:26.680 --> 00:22:28.900 rat does not build a population on a new island. 00:22:29.380 --> 00:22:31.380 Exactly. You need at least a pregnant female 00:22:31.380 --> 00:22:34.160 to survive the trip. Or a breeding pair that 00:22:34.160 --> 00:22:37.259 somehow both make it. The odds against that seem 00:22:37.259 --> 00:22:39.559 genuinely astronomical. It feels impossible. 00:22:39.700 --> 00:22:42.500 It is effectively impossible in any human timeframe. 00:22:42.759 --> 00:22:44.460 If you stood on the beach for a lifetime, you'd 00:22:44.460 --> 00:22:47.619 never see it happen. But here is the magic of 00:22:47.619 --> 00:22:51.230 deep geological time. If you give the impossible 00:22:51.230 --> 00:22:53.950 a million years to happen, it eventually becomes 00:22:53.950 --> 00:22:56.269 inevitable. Exactly. If you roll the multi -sided 00:22:56.269 --> 00:22:59.109 dice every single major flood season for two 00:22:59.109 --> 00:23:02.130 million years, eventually one day you roll that 00:23:02.130 --> 00:23:05.289 perfect double six. So one day, against literally 00:23:05.289 --> 00:23:08.269 all the odds in the universe, this battered, 00:23:08.329 --> 00:23:11.029 shrinking raft of vegetation, with a very thirsty, 00:23:11.170 --> 00:23:13.529 very traumatized, pregnant rat clinging to it, 00:23:13.549 --> 00:23:16.269 crashes onto the pristine white limestone shores 00:23:16.269 --> 00:23:20.519 of Barbuda, cast up, Now you see why he chose 00:23:20.519 --> 00:23:22.759 that name. It hits so much harder now. It really 00:23:22.759 --> 00:23:25.059 was physically cast up by the sea. And once they 00:23:25.059 --> 00:23:27.400 finally stumble off that raft onto the dry land, 00:23:27.759 --> 00:23:30.059 the entire game of survival changes. They are 00:23:30.059 --> 00:23:32.359 in a totally new world. And Ray actually had 00:23:32.359 --> 00:23:34.700 a very strong theory about exactly who was on 00:23:34.700 --> 00:23:36.960 that original raft, didn't he? Where they originally 00:23:36.960 --> 00:23:40.269 came from on the mainland. He did. By closely 00:23:40.269 --> 00:23:42.950 analyzing the skull morphology, he pointed to 00:23:42.950 --> 00:23:46.390 a mainland species called Orizomys albigularis 00:23:46.390 --> 00:23:49.650 as the closest living relative. OK. As a quick 00:23:49.650 --> 00:23:53.089 aside, taxonomy never sleeps. So today, that 00:23:53.089 --> 00:23:56.450 specific species has actually been moved by geneticists 00:23:56.450 --> 00:23:59.450 into a new genus called Nephelomys. Nephelomys. 00:23:59.490 --> 00:24:01.569 But the common name is really the key detail 00:24:01.569 --> 00:24:04.490 here. They're known as the cloud forest rats. 00:24:04.779 --> 00:24:07.940 Cloud forest, that sounds cold and wet. It is. 00:24:08.220 --> 00:24:10.039 These are rats that live high up in the Andes 00:24:10.039 --> 00:24:12.700 Mountains and in the cool high altitude highlands 00:24:12.700 --> 00:24:15.400 of Panama and Venezuela. They live in misty, 00:24:15.579 --> 00:24:18.180 chilly, wet mountainous forests. Exactly. It 00:24:18.180 --> 00:24:20.299 seems like the exact opposite of a sun -baked 00:24:20.299 --> 00:24:22.819 Caribbean beach on Antigua. It is as different 00:24:22.819 --> 00:24:25.079 an environment as you can get, but they share 00:24:25.079 --> 00:24:27.640 the underlying skull architecture with our island 00:24:27.640 --> 00:24:31.000 giant. So they have that same robust brain case, 00:24:31.079 --> 00:24:34.779 the specific crests on the bone? Yes. Which heavily 00:24:34.779 --> 00:24:37.140 implies that the small ancestor of eclatomace 00:24:37.140 --> 00:24:39.539 somehow washed down from those cool mountains 00:24:39.539 --> 00:24:42.319 during a flood, survived the brutal tropical 00:24:42.319 --> 00:24:45.339 ocean crossing, and then had to immediately adapt 00:24:45.339 --> 00:24:48.319 to a radically different, dry, scrubby climate 00:24:48.319 --> 00:24:51.140 on Antigua. Talk about culture shock. You go 00:24:51.140 --> 00:24:55.279 from the misty, cool Andes to a limestone scrub 00:24:55.279 --> 00:24:57.900 forest at sea level in the Caribbean. It's extreme. 00:24:58.160 --> 00:25:00.480 And that intense environmental pressure combined 00:25:00.480 --> 00:25:03.039 with the isolation is what drove the gigantism. 00:25:03.119 --> 00:25:05.039 The gigantism. because they didn't start out 00:25:05.039 --> 00:25:07.819 giant. No, the ancestor was relatively small. 00:25:08.240 --> 00:25:10.440 This transformation is an example of a classic 00:25:10.440 --> 00:25:12.619 biological principle called the island rule. 00:25:12.859 --> 00:25:14.980 The island rule. Is that the one where small 00:25:14.980 --> 00:25:17.079 things get big and big things get small? Exactly 00:25:17.079 --> 00:25:20.400 that. Foster's rule. If you are a large animal 00:25:20.400 --> 00:25:22.680 on the mainland, like an elephant, and you get 00:25:22.680 --> 00:25:24.680 trapped on an island - You shrink. Right. You 00:25:24.680 --> 00:25:26.960 become a dwarf elephant over generations because 00:25:26.960 --> 00:25:29.420 there simply isn't enough food or land to support 00:25:29.420 --> 00:25:31.640 massive bodies. But if you are a small animal, 00:25:31.740 --> 00:25:35.190 like a rat - You get huge. Why? Why is - bigger, 00:25:35.490 --> 00:25:37.569 suddenly better for a rat on an island. It's 00:25:37.569 --> 00:25:39.990 a combination of several factors. First and foremost, 00:25:40.450 --> 00:25:42.829 a total lack of predators. Right. On the South 00:25:42.829 --> 00:25:45.690 American mainland, if you are a rat, you stay 00:25:45.690 --> 00:25:49.269 small so you can hide in tiny crevices from jaguars, 00:25:49.569 --> 00:25:52.109 ocelots, foxes, eagles. Everything wants to eat 00:25:52.109 --> 00:25:56.410 you. But on ancient Antigua, there are no mammalian 00:25:56.410 --> 00:26:00.190 carnivores. None. No wild cats, no wolves. You 00:26:00.190 --> 00:26:02.430 are perfectly safe. You don't need to scurry 00:26:02.430 --> 00:26:04.970 and hide in tiny holes anymore. You can relax. 00:26:05.170 --> 00:26:07.789 Okay, safety is one thing. Second is competition. 00:26:08.529 --> 00:26:11.109 If there are limited resources and you are slightly 00:26:11.109 --> 00:26:13.390 bigger than your siblings, you can physically 00:26:13.390 --> 00:26:15.829 bully other members of your own species to get 00:26:15.829 --> 00:26:18.490 the best food. Size gives you dominance. And 00:26:18.490 --> 00:26:20.549 third, which is very important for our grinding 00:26:20.549 --> 00:26:23.900 rat, is metabolic efficiency. A larger body mass 00:26:23.900 --> 00:26:25.940 with a longer digestive tract actually helps 00:26:25.940 --> 00:26:28.660 you process the coarser, lower quality vegetation 00:26:28.660 --> 00:26:30.859 that you find on a dry island. Which perfectly 00:26:30.859 --> 00:26:32.960 aligns with those massive grinding molars we 00:26:32.960 --> 00:26:35.160 talked about earlier. Exactly. It all fits together. 00:26:35.240 --> 00:26:37.460 So over thousands and thousands of generations, 00:26:37.759 --> 00:26:40.740 this little, terrified, cloud forest refugee 00:26:40.740 --> 00:26:44.859 slowly puffs up into the giant, confident Ekbultemis. 00:26:45.220 --> 00:26:48.619 And it essentially becomes the dominant terrestrial 00:26:48.619 --> 00:26:51.890 mammal of the entire island system. I really 00:26:51.890 --> 00:26:54.609 want to talk about what that daily life was actually 00:26:54.609 --> 00:26:57.950 like for them. The ecology. Yeah, because reading 00:26:57.950 --> 00:27:00.789 the source material, we actually have a surprisingly 00:27:00.789 --> 00:27:04.970 vivid detailed picture of the exact ecosystem 00:27:04.970 --> 00:27:08.049 Iqbaltami's lived in. We do. We know its neighbors. 00:27:08.390 --> 00:27:11.240 And we know this thanks to... of all things, 00:27:11.779 --> 00:27:15.579 fossilized owl vomit. Yes, the absolute glamour 00:27:15.579 --> 00:27:17.759 of paleontology. That's amazing. We honestly 00:27:17.759 --> 00:27:19.960 owe almost everything we know about the small 00:27:19.960 --> 00:27:23.380 extinct animals of the Caribbean to the burrowing 00:27:23.380 --> 00:27:25.819 owl. Okay, you have to explain that process for 00:27:25.819 --> 00:27:28.299 us. How exactly does an owl become the premier 00:27:28.299 --> 00:27:30.839 fossil collector of the Caribbean? It's a field 00:27:30.839 --> 00:27:33.900 of study called taphonomy. The study of how organisms 00:27:33.900 --> 00:27:36.500 die, decay, and become fossilized over time. 00:27:37.019 --> 00:27:39.920 And owls happen to be fantastic natural taphonomic 00:27:39.920 --> 00:27:42.380 agents. Because of how they eat. Right. Owls 00:27:42.380 --> 00:27:45.700 swallow their smaller prey whole. Rats, lizards, 00:27:45.799 --> 00:27:47.900 little birds down the hatch in one piece. Gruesome. 00:27:48.140 --> 00:27:50.319 But their stomach acids, while they digest all 00:27:50.319 --> 00:27:52.599 the meat and soft tissue, they can't handle the 00:27:52.599 --> 00:27:55.599 hard stuff. They can't digest bones, teeth, or 00:27:55.599 --> 00:27:57.880 fur. So they have to get rid of it. So a few 00:27:57.880 --> 00:28:01.359 hours after eating, the owl regurgitates a dense, 00:28:01.420 --> 00:28:04.559 compact little pellet that contains all the clean, 00:28:04.799 --> 00:28:07.460 perfectly concentrated bones of whatever it just 00:28:07.460 --> 00:28:10.480 ate. It's literally like a pre -packaged, perfectly 00:28:10.480 --> 00:28:13.359 curated museum exhibit just waiting to be found. 00:28:13.680 --> 00:28:16.940 Precisely. And here's the key. These burrowing 00:28:16.940 --> 00:28:19.799 owls, Athene cunicularia, they tend to live in 00:28:19.799 --> 00:28:22.700 limestone caves or under rocky overhangs. And 00:28:22.700 --> 00:28:24.799 they roost in the exact same spot year after 00:28:24.799 --> 00:28:27.769 year. generation after generation for millennia. 00:28:28.069 --> 00:28:30.670 So over thousands of years, these pellets just 00:28:30.670 --> 00:28:33.130 drop to the cave floor and pile up. A mountain 00:28:33.130 --> 00:28:35.349 of data. They break down, they get buried in 00:28:35.349 --> 00:28:37.789 the fine cave dust and sediment, and they preserve 00:28:37.789 --> 00:28:40.190 an absolutely perfect high resolution snapshot 00:28:40.190 --> 00:28:42.609 of everything that was living and scurrying around 00:28:42.609 --> 00:28:44.769 in the immediate area. So when Clayton Ray was 00:28:44.769 --> 00:28:47.250 doing his field work excavating those sites in 00:28:47.250 --> 00:28:49.309 Barbuda places with great names like Two Foot 00:28:49.309 --> 00:28:51.950 Bay and Suffers. Or Mill Reef and Indian Creek 00:28:51.950 --> 00:28:54.819 over on Antigua. Right. When he was digging there, 00:28:55.180 --> 00:28:57.099 he was essentially just digging through thousands 00:28:57.099 --> 00:29:00.799 of years of ancient owl toilets. That is factually 00:29:00.799 --> 00:29:03.880 correct, yes. He described finding these distinct 00:29:03.880 --> 00:29:06.900 layers of red to yellow, unconsolidated sediment. 00:29:07.099 --> 00:29:10.039 Loose dirt? Loose, dry dirt that was absolutely 00:29:10.039 --> 00:29:13.220 packed with thousands of microbones. So let's 00:29:13.220 --> 00:29:15.519 use that data to reconstruct the scene. Let's 00:29:15.519 --> 00:29:18.619 imagine it's, say, 2 ,000 years ago on Barbuda. 00:29:18.680 --> 00:29:20.980 OK. We're standing outside the caves at Two Foot 00:29:20.980 --> 00:29:24.259 Bay at twilight. What are we seeing and hearing 00:29:24.259 --> 00:29:26.380 around us? Well, first of all, it's a very busy, 00:29:26.559 --> 00:29:29.960 very noisy ecosystem. It is not quiet. OK. Based 00:29:29.960 --> 00:29:32.079 directly on what we found in those owl pellets, 00:29:32.359 --> 00:29:34.700 the ground all around you is just alive with 00:29:34.700 --> 00:29:37.619 reptiles. Lots of lizards. Everywhere. You have 00:29:37.619 --> 00:29:40.480 thecidactylus rapicata. Thecidactylus, what is 00:29:40.480 --> 00:29:42.940 that? The common name is the turnip -tailed gecko. 00:29:43.059 --> 00:29:45.319 Turnip tails. There are these big, chunky, very 00:29:45.319 --> 00:29:47.799 vocal nocturnal geckos. So you hear them barking 00:29:47.799 --> 00:29:50.819 and clicking. OK, clicking geckos. You also have 00:29:50.819 --> 00:29:52.910 fast -moving ground lizards. It's darting through 00:29:52.910 --> 00:29:55.950 the leaves, like fallidocilis grazoldi. Try saying 00:29:55.950 --> 00:29:59.109 that three times fast. I won't. And up in the 00:29:59.109 --> 00:30:02.549 branches, you have anolis litchi, the large tree 00:30:02.549 --> 00:30:05.130 anoles. So there is just constant rustling in 00:30:05.130 --> 00:30:07.829 the dry leaves. The ground is moving. And what 00:30:07.829 --> 00:30:10.890 about the birds? The limestone cliffs and caves 00:30:10.890 --> 00:30:14.380 would be echoing. The pellets show huge numbers 00:30:14.380 --> 00:30:17.220 of seabirds nesting right there, especially shearwaters. 00:30:17.500 --> 00:30:20.519 The puffinous species. Right. And shearwaters, 00:30:20.579 --> 00:30:23.039 if you've never heard them, they make this incredibly 00:30:23.039 --> 00:30:26.279 eerie, ghostly, wailing call when they return 00:30:26.279 --> 00:30:28.279 to their nests at night. It sounds like a crying 00:30:28.279 --> 00:30:30.180 baby or something, doesn't it? Like a crying 00:30:30.180 --> 00:30:32.720 baby or a ghost moaning. It's very unsettling. 00:30:32.859 --> 00:30:35.420 Creepy ambience. Very. Now, add the bats. The 00:30:35.420 --> 00:30:37.660 sediment is full of bat bones. So the sky is 00:30:37.660 --> 00:30:40.799 full of them. Huge swarms of mormoups and nautilus 00:30:40.799 --> 00:30:43.000 bats sw - whirling around the cave entrances 00:30:43.000 --> 00:30:46.259 at dusk, catching insects. And frogs. Yes, the 00:30:46.259 --> 00:30:49.400 tiny whistling frogs, Aliferidactylus johnstoni, 00:30:49.400 --> 00:30:51.519 calling constantly from the damp spot. So it 00:30:51.519 --> 00:30:54.119 is an absolute cacophony. It is wild. We've got 00:30:54.119 --> 00:30:56.599 peeping frogs, squeaking bats, wailing ghost 00:30:56.599 --> 00:30:59.099 birds, clicking geckos. And moving through the 00:30:59.099 --> 00:31:01.740 middle of all this noise and chaos is our giant 00:31:01.740 --> 00:31:04.980 capillutomys. The king of the ground. It's big, 00:31:05.279 --> 00:31:07.960 and compared to a skittish mainland rat, it's 00:31:07.960 --> 00:31:10.819 probably relatively slow moving. It has no reach. 00:31:10.640 --> 00:31:14.299 It's just lumbering along, foraging for tough 00:31:14.299 --> 00:31:16.559 seeds. Maybe occasionally raiding one of those 00:31:16.559 --> 00:31:18.559 shearwater nests on the ground to eat an egg. 00:31:18.799 --> 00:31:20.960 And of course, occasionally getting snatched 00:31:20.960 --> 00:31:23.700 up in the dark by a very ambitious burrowing 00:31:23.700 --> 00:31:26.960 owl. Which frankly is impressive, because burrowing 00:31:26.960 --> 00:31:29.779 owls are not huge birds. They are relatively 00:31:29.779 --> 00:31:32.920 small, long -legged owls. So taking down a cat 00:31:32.920 --> 00:31:35.460 -sized rat is a big deal. It suggests the owls 00:31:35.460 --> 00:31:38.000 were probably mostly hunting the juveniles, the 00:31:38.000 --> 00:31:41.450 younger rats, because of full -grown, heavy adult 00:31:41.450 --> 00:31:44.650 ecboltomus might literally be too heavy for a 00:31:44.650 --> 00:31:47.250 burrowing owl to lift. But the sheer number of 00:31:47.250 --> 00:31:50.309 bones shows that this rat was a staple, everyday 00:31:50.309 --> 00:31:52.690 food source. It was the primary protein bar of 00:31:52.690 --> 00:31:54.670 the island ecosystem. Everything relied on it. 00:31:54.789 --> 00:31:57.069 It really paints such a beautiful picture of 00:31:57.069 --> 00:31:59.789 a highly functional, entirely self -contained 00:31:59.789 --> 00:32:02.069 world. It does. You know, we so often think of 00:32:02.069 --> 00:32:05.150 islands as these fragile, broken ecosystems just 00:32:05.150 --> 00:32:07.450 waiting for humans to arrive and mismanage them. 00:32:07.789 --> 00:32:09.970 But this was working perfectly find without us. 00:32:10.210 --> 00:32:13.269 It was a perfectly balanced equation. The lizards, 00:32:13.450 --> 00:32:16.410 the giant grinding rats, the owls, the bats. 00:32:16.829 --> 00:32:19.349 They had all been dancing this intricate evolutionary 00:32:19.349 --> 00:32:21.849 dance together for thousands of years. Until 00:32:21.849 --> 00:32:24.089 the music completely stopped. Until the music 00:32:24.089 --> 00:32:26.750 stopped. And this brings us to the harsh reality. 00:32:27.309 --> 00:32:30.490 Section five of our outline. The extinction event. 00:32:30.670 --> 00:32:33.250 The end of the line. We know, obviously, that 00:32:33.250 --> 00:32:36.390 eclatomace is gone today. The big question is, 00:32:36.509 --> 00:32:38.900 who killed it? Well, in paleontology globally, 00:32:39.420 --> 00:32:41.940 we argue about extinction causes all the time. 00:32:42.039 --> 00:32:44.359 Was it an asteroid? Was it a volcano? Was it 00:32:44.359 --> 00:32:47.460 climate change? Right. But when you are studying 00:32:47.460 --> 00:32:50.299 the extinction of endemic Caribbean mammals, 00:32:50.740 --> 00:32:53.400 the answer is almost always painfully the same. 00:32:53.799 --> 00:32:56.279 And the definitive evidence for that answer is 00:32:56.279 --> 00:32:58.259 buried right there in the dirt of those caves, 00:32:58.380 --> 00:33:01.140 isn't it? It is written clearly in the stratigraphy, 00:33:01.380 --> 00:33:04.039 the physical layers of the cave floor. Walk us 00:33:04.039 --> 00:33:06.140 through those layers because this is fascinating. 00:33:06.259 --> 00:33:09.079 Think of the cave floor deposit as a giant layer 00:33:09.079 --> 00:33:11.940 cake of history. Okay, a cake. The thickest, 00:33:12.220 --> 00:33:14.900 bottom -most layer of that cake is that yellow 00:33:14.900 --> 00:33:17.000 to red loose sediment we just talked about. The 00:33:17.000 --> 00:33:20.140 owl pellet layer. Right. That thick layer represents 00:33:20.140 --> 00:33:23.960 the old world. It is absolutely packed with the 00:33:23.960 --> 00:33:27.599 bones of Ekbuldemiz, the native geckos, the local 00:33:27.599 --> 00:33:30.019 bats. And chronologically, how much time does 00:33:30.019 --> 00:33:33.440 that yellow layer cover? It spans many thousands 00:33:33.440 --> 00:33:36.140 of years. It dates from the late Quaternary, 00:33:36.299 --> 00:33:38.720 the Pleistocene Ice Age, all the way up through 00:33:38.720 --> 00:33:40.779 the Holocene. Meaning it continues right up through 00:33:40.779 --> 00:33:42.940 the arrival of the very first humans in the Caribbean. 00:33:43.099 --> 00:33:46.779 Yes, that's a crucial point. The giant rat actually 00:33:46.779 --> 00:33:49.940 survived the first waves of human arrival. Who 00:33:49.940 --> 00:33:52.539 were they? The Amerindians, primarily the Saladoid 00:33:52.539 --> 00:33:55.420 peoples, they arrived in Antigua and Barbuda 00:33:55.420 --> 00:33:58.799 roughly around 2500 BCE. So they shared the island. 00:33:59.240 --> 00:34:02.319 They did. We actually find Ekwodamese bones mixed 00:34:02.319 --> 00:34:04.500 into the archaeological middens, the ancient 00:34:04.500 --> 00:34:06.420 trash heaps of these indigenous peoples. Meaning 00:34:06.420 --> 00:34:08.219 they were hunting and eating the giant rats. 00:34:08.400 --> 00:34:10.940 They were. It was a large, meaty animal. But 00:34:10.940 --> 00:34:13.519 hunting them didn't wipe them out. No. The overall 00:34:13.519 --> 00:34:15.860 population of the rats might have dipped slightly, 00:34:16.059 --> 00:34:18.179 but they had coexisted for a very long time. 00:34:18.780 --> 00:34:20.980 The indigenous hunting and agricultural practices 00:34:20.980 --> 00:34:23.739 were relatively low impact compared to what came 00:34:23.739 --> 00:34:26.360 later. They didn't completely clear cut the habitat. 00:34:26.619 --> 00:34:29.480 Exactly. The giant rat and the indigenous humans 00:34:29.480 --> 00:34:32.800 shared those islands for over three millennia. 00:34:33.119 --> 00:34:34.800 OK, so looking back at our soil cake, we have 00:34:34.800 --> 00:34:38.460 this thick yellow layer showing humans and giant 00:34:38.460 --> 00:34:41.300 rats living together. Then what happens is you 00:34:41.300 --> 00:34:43.159 move up the dirt. Then you hit a very sharp, 00:34:43.260 --> 00:34:45.800 very sudden line in the soil. The yellow dirt 00:34:45.800 --> 00:34:48.900 just stops abruptly. And right above it, sitting 00:34:48.900 --> 00:34:52.480 on top, you get a distinct layer of very dark, 00:34:52.800 --> 00:34:55.309 organic, rich sediment. The dark layer. That 00:34:55.309 --> 00:34:57.530 sounds incredibly ominous. It is the stark boundary 00:34:57.530 --> 00:35:00.449 line of the colonial era. And in that dark sediment 00:35:00.449 --> 00:35:04.250 layer, Ekboldimis just vanishes. The bones disappear 00:35:04.250 --> 00:35:06.929 completely. It is entirely absent from the upper 00:35:06.929 --> 00:35:08.909 record. And what replaces it in that dark soil? 00:35:09.170 --> 00:35:11.969 Raddus. Raddus. The European rats. Specifically, 00:35:12.210 --> 00:35:14.889 Raddus raddus, the black rat, and Raddus norvegicus, 00:35:15.110 --> 00:35:17.309 the brown rat. The ship rats. And crucially, 00:35:17.590 --> 00:35:20.030 raddus does not cross oceans by rafting on random 00:35:20.030 --> 00:35:23.030 mats of vegetation. No. Raddus travels comfortably 00:35:23.030 --> 00:35:25.510 in the holds of massive wooden sailing ships. 00:35:25.809 --> 00:35:27.849 The sudden appearance of Raddus bones in that 00:35:27.849 --> 00:35:30.610 upper layer is the definitive geological marker 00:35:30.610 --> 00:35:34.409 for the arrival of Europeans post -1500 AD. It 00:35:34.409 --> 00:35:37.889 is amazing. in a sad way, that the geology is 00:35:37.889 --> 00:35:40.389 that incredibly precise. Yeah. You can literally 00:35:40.389 --> 00:35:42.349 drag your finger up the cave wall and see the 00:35:42.349 --> 00:35:44.730 exact moment Columbus and the subsequent colonizers 00:35:44.730 --> 00:35:47.670 arrived. It is a stark, devastating line in the 00:35:47.670 --> 00:35:50.769 earth. One world ends entirely, and a completely 00:35:50.769 --> 00:35:53.610 different one begins. So why exactly is the European 00:35:53.610 --> 00:35:56.170 rat such an unstoppable killer in this scenario? 00:35:56.550 --> 00:35:58.929 I mean, think about it. Ekbultemis is a giant. 00:35:59.150 --> 00:36:01.269 It's the size of a cat. Rattus is relatively 00:36:01.269 --> 00:36:04.110 small. Sure. In a one -on -one cage match, I 00:36:04.110 --> 00:36:07.230 am absolutely betting my money on the giant Caribbean 00:36:07.230 --> 00:36:09.449 rat. And in a pure physical cage match, you'd 00:36:09.449 --> 00:36:12.510 be right. Agultamese wins easily. But evolution 00:36:12.510 --> 00:36:15.010 and extinction isn't a cage match, it is a numbers 00:36:15.010 --> 00:36:17.590 game. A numbers game. And Rattus is the ultimate 00:36:17.590 --> 00:36:20.309 biological cheat code in the numbers game. How 00:36:20.309 --> 00:36:22.929 so? Unpack their strategy. First and foremost, 00:36:23.630 --> 00:36:26.449 rapid reproduction. They breed fast. Insanely 00:36:26.449 --> 00:36:29.980 fast. An island giant like Ekbultemes, having 00:36:29.980 --> 00:36:32.820 lived with zero predators for millions of years, 00:36:33.079 --> 00:36:36.260 almost certainly evolved a very slow life history. 00:36:36.539 --> 00:36:37.920 Because they didn't need to replace themselves 00:36:37.920 --> 00:36:40.559 quickly. Right. They likely had fewer babies' 00:36:40.619 --> 00:36:43.699 poo litter, a much longer gestation period, and 00:36:43.699 --> 00:36:45.760 took a longer time to reach sexual maturity. 00:36:45.840 --> 00:36:48.739 Whereas the European rat... Explodes in population. 00:36:48.980 --> 00:36:51.860 The giants simply could not reproduce fast enough 00:36:51.860 --> 00:36:53.900 to sustain their numbers under new pressure. 00:36:54.019 --> 00:36:57.469 They just swarmed them. Swarmed. Second... Rattus 00:36:57.469 --> 00:37:01.130 is a highly aggressive, hyper -adaptable generalist. 00:37:01.429 --> 00:37:03.869 They will eat literally anything. So they stole 00:37:03.869 --> 00:37:06.590 the food. They absolutely would have outcompeted 00:37:06.590 --> 00:37:08.610 Iqbaltomys for the seeds and plants it relied 00:37:08.610 --> 00:37:12.369 on. But much worse, European rats are notorious 00:37:12.369 --> 00:37:15.550 egg and nest predators. They likely hunted and 00:37:15.550 --> 00:37:18.070 ate the juvenile Iqbaltomys right out of their 00:37:18.070 --> 00:37:19.949 nest before they could ever grow into giants. 00:37:20.010 --> 00:37:22.050 So they cut off the next generation. And finally, 00:37:22.349 --> 00:37:25.690 perhaps the most deadly factor, disease. Biological 00:37:25.690 --> 00:37:28.639 warfare. Almost certainly. Bratis carries a whole 00:37:28.639 --> 00:37:31.800 host of continental pathogens, fleas and viruses 00:37:31.800 --> 00:37:35.400 that the native isolated island rodents had absolutely 00:37:35.400 --> 00:37:38.679 zero immune defense against. It's the exact same 00:37:38.679 --> 00:37:41.199 tragic story as the human populations of the 00:37:41.199 --> 00:37:43.920 Americas encountering European diseases. It is 00:37:43.920 --> 00:37:46.579 a terrible parallel. Yes. So the extinction wasn't 00:37:46.579 --> 00:37:49.079 a giant battle. It wasn't a bang. It was just 00:37:49.079 --> 00:37:52.260 a whimper, a slow choking, inevitable squeeze, 00:37:52.539 --> 00:37:55.440 a deadly squeeze, but one that happened incredibly 00:37:55.440 --> 00:37:58.900 fast in geological. time. Within just a few short 00:37:58.900 --> 00:38:01.860 decades of European ships dropping anchor, a 00:38:01.860 --> 00:38:04.420 unique biological lineage that had successfully 00:38:04.420 --> 00:38:07.480 survived for millions of years was completely 00:38:07.480 --> 00:38:10.489 wiped out. And it wasn't just limited to Antigua 00:38:10.489 --> 00:38:13.150 and Barbuda, was it? The outline mentions this 00:38:13.150 --> 00:38:15.969 mysterious, undescribed species bee showing up 00:38:15.969 --> 00:38:18.170 elsewhere. Yes. And this is where the scale of 00:38:18.170 --> 00:38:19.849 the tragedy really widens. What did they find? 00:38:20.030 --> 00:38:22.309 In recent years, archaeologists digging in middens 00:38:22.309 --> 00:38:25.230 on other islands, specifically Guadalupe, Montserrat, 00:38:25.389 --> 00:38:27.710 and Marie Galante, have found the scattered bones 00:38:27.710 --> 00:38:30.949 of a very similar massive rice rat. Also labeled 00:38:30.949 --> 00:38:34.150 undescribed species bee. Exactly. The morphology 00:38:34.150 --> 00:38:37.590 is so close that it strongly suggests that either 00:38:37.590 --> 00:38:40.670 Agbultimus itself or its very, very close cousins 00:38:40.670 --> 00:38:43.730 were actually the dominant ground mammals across 00:38:43.730 --> 00:38:45.969 that entire section of the Lua chain. They weren't 00:38:45.969 --> 00:38:48.269 just a localized fluke. They were a regional 00:38:48.269 --> 00:38:51.170 empire. They were a massive evolutionary success 00:38:51.170 --> 00:38:53.670 story. They had conquered multiple islands. They 00:38:53.670 --> 00:38:56.030 were everywhere. And they all fell to the exact 00:38:56.030 --> 00:38:59.159 same enemy. The dark sediment layer is found 00:38:59.159 --> 00:39:01.900 in the caves of all those islands. The story 00:39:01.900 --> 00:39:04.659 is identically grim across the board. The wooden 00:39:04.659 --> 00:39:08.059 ships arrive. The European rats disembark. The 00:39:08.059 --> 00:39:10.760 native giants completely disappear. It really 00:39:10.760 --> 00:39:12.840 brings us right back to the start of this entire 00:39:12.840 --> 00:39:15.960 conversation. The profound irony of this animal's 00:39:15.960 --> 00:39:18.159 existence. It is deeply, deeply ironic. If you 00:39:18.159 --> 00:39:19.679 just take a step back and look at the resume 00:39:19.679 --> 00:39:22.190 of the species. Let's review it. It starts out 00:39:22.190 --> 00:39:25.389 as a small, shivering rat in the high, misty 00:39:25.389 --> 00:39:28.070 cloud forests of the Andes. It gets swept into 00:39:28.070 --> 00:39:30.949 a raging river, survives a brutal, seemingly 00:39:30.949 --> 00:39:33.409 impossible Sinbad voyage across the ocean on 00:39:33.409 --> 00:39:36.269 a tangle of roots, a literal miracle of survival 00:39:36.269 --> 00:39:39.590 at sea. It washes ashore, a cast away. It conquers 00:39:39.590 --> 00:39:42.750 an entirely new alien landscape. It fundamentally 00:39:42.750 --> 00:39:45.949 changes its own biology. It reshapes its skull, 00:39:46.289 --> 00:39:48.750 alters its teeth, and blows up its body size 00:39:48.750 --> 00:39:51.170 to completely master that limestone terrain. 00:39:51.510 --> 00:39:54.489 It survives massive Caribbean hurricanes. It 00:39:54.489 --> 00:39:56.809 survives the rising sea levels at the end of 00:39:56.809 --> 00:39:59.349 the global ice age when the islands shrink. It 00:39:59.349 --> 00:40:01.869 even survives the arrival of the first spear 00:40:01.869 --> 00:40:04.170 -wielding human hunters living alongside them 00:40:04.170 --> 00:40:06.789 for thousands of years. It survives all of that. 00:40:07.099 --> 00:40:10.480 But it could not survive the year 1500 AD. It 00:40:10.480 --> 00:40:12.820 could not survive the globalization of the common 00:40:12.820 --> 00:40:15.980 rat. And now, the final, most bitter irony of 00:40:15.980 --> 00:40:19.420 all? It can't even survive the rigid bureaucracy 00:40:19.420 --> 00:40:22.079 of human science. It sits quietly in a museum 00:40:22.079 --> 00:40:24.800 drawer, permanently unnamed. A literal ghost 00:40:24.800 --> 00:40:27.159 species. It really is a poignant reminder that 00:40:27.159 --> 00:40:29.460 extinction doesn't just physically erase the 00:40:29.460 --> 00:40:31.900 living animal from the earth. Sometimes, it eventually 00:40:31.900 --> 00:40:34.380 erases the very memory of the animal from our 00:40:34.380 --> 00:40:36.599 records. Which is terrifying. Think about it. 00:40:36.969 --> 00:40:39.969 If Clayton Ray hadn't been incredibly diligent 00:40:39.969 --> 00:40:43.469 in the 1960s, if he hadn't written that specific 00:40:43.469 --> 00:40:46.389 brilliant thesis, we wouldn't even know enough 00:40:46.389 --> 00:40:49.130 today to call it undescribed species B. It would 00:40:49.130 --> 00:40:51.909 just be a box of weird oversized bones gathering 00:40:51.909 --> 00:40:55.170 dust on a shelf. Just a geological anomaly nobody 00:40:55.170 --> 00:40:57.269 bothered to look at closely. And that is the 00:40:57.269 --> 00:40:59.489 one thought that I really cannot shake as we 00:40:59.489 --> 00:41:02.289 wrap this up. We only know about this specific 00:41:02.289 --> 00:41:05.599 ghost because Ray was diligent, but How many 00:41:05.599 --> 00:41:07.800 other drawers are out there? Oh, that is the 00:41:07.800 --> 00:41:10.519 big open question in paleontology. I mean, every 00:41:10.519 --> 00:41:13.840 major natural history museum in the world, London, 00:41:14.119 --> 00:41:16.679 Paris, New York, Washington, D .C., they all 00:41:16.679 --> 00:41:19.960 have massive labyrinthine basements full of what 00:41:19.960 --> 00:41:23.159 they call unprocessed material. Millions of specimens, 00:41:23.480 --> 00:41:25.940 boxes of bones collected hastily by explorers 00:41:25.940 --> 00:41:28.960 in the 1800s, fragile fossils dug out of quarries 00:41:28.960 --> 00:41:31.199 in the 1920s that got packed away during a war 00:41:31.199 --> 00:41:33.000 and never opened again. They're all just sitting 00:41:33.000 --> 00:41:37.349 there in the dark. waiting for a story. Exactly. 00:41:37.710 --> 00:41:41.050 How many other forgotten ghost species are currently 00:41:41.050 --> 00:41:44.250 hiding in plain sight? How many other impossible 00:41:44.250 --> 00:41:47.130 Sinbad voyages are locked away in a steel cabinet 00:41:47.130 --> 00:41:49.630 right now, just waiting for a curious grad student 00:41:49.630 --> 00:41:51.989 to pull open the drawer, take the millimeter 00:41:51.989 --> 00:41:54.590 measurements, and finally write the right paper? 00:41:55.170 --> 00:41:58.460 We tend to romanticize exploration. We think 00:41:58.460 --> 00:42:01.159 it means going out into the unmapped jungle with 00:42:01.159 --> 00:42:03.219 a machete and a pith helmet. But sometimes the 00:42:03.219 --> 00:42:05.460 most important exploration is just going down 00:42:05.460 --> 00:42:07.559 into the climate -controlled basement with a 00:42:07.559 --> 00:42:10.239 pair of digital calipers and a strong cup of 00:42:10.239 --> 00:42:13.139 coffee. The history of life on Earth is far from 00:42:13.139 --> 00:42:16.320 finished. It is still being written, and a huge 00:42:16.320 --> 00:42:18.780 chunk of it is going to be found quietly waiting 00:42:18.780 --> 00:42:21.079 in the archives. I couldn't agree more. Well, 00:42:21.500 --> 00:42:24.929 here is to epitomies. The cast -up mouse. May 00:42:24.929 --> 00:42:27.190 it one day finally get its official name on the 00:42:27.190 --> 00:42:29.989 deed. Here, here, I hope so too. Thanks for taking 00:42:29.989 --> 00:42:32.110 this deep dive with us today. It was my absolute 00:42:32.110 --> 00:42:33.889 pleasure. And we will catch you all on the next 00:42:33.889 --> 00:42:34.050 one.