Episode 236 - Chalicotheres

You're listening to the Common Descent Podcast. Hello, David. Hello, Will. And hello, listeners. Welcome to episode 236 of the Common Descent Podcast. This episode, we are discussing callicatherers. I'm so excited. Yeah, this is a particularly odd group of fossil mammals that sometimes gets overlooked, I think partially because they're very strange and very mysterious. Yeah, certainly among the most famous, not famous fossil groups. Absolutely. These are the odd clawed persidactyls, hooved mammals with claws that were kind of shaped like horse gorillas. Yep. We will be discussing this topic as always because it was requested by a fair number of people lending to the most popular least known. Yes. Just so many people saying, please explain this. Yes. What is going on with these animals? This was requested by Jenna, Bill, Brett, Johan, Bia, Oswaldo, Patty, Aaron, Danielle, Jarrett, Desi, Noah, Robert, Rowan, and Graham. Also me, I also want you to explain what's going on with these animals. Happily. We'll be discussing what these creatures are, how the mystery that surrounded them and surrounds them still slowly was discovered and unfolded throughout history, and what are some of the ideas for how these strange animals might have lived. But before we get into that discussion, some quick announcements and then our news section. First announcement, as always, is that we have a Patreon. Our Patreon funds the podcast from top to bottom. It allows us to do all the amazing things that we get to do and focus more of our time and efforts on the podcast. And when you sign up, you get some extra goodies. This is bonus episodes, bonus content, live streams with us, gifts at certain levels. And one of those potential benefits is to have your name shouted out here at the beginning of the podcast. So this episode, we would like to welcome Kelly and Melissa. Welcome and thank you for your incredible support to all of our patrons. Dear listeners, if you would like to help not only morally but financially support our science communication efforts, find the link to the Patreon in the episode description. Absolutely. Another way you can send us support is we have a physical mailing address. You can see that down in our info as well. And we got some mail. We got a very sweet letter from Colt and some stickers from the fossil event that they organized thanking us for talking to their classes and their students. Yeah, we did a little talk to the community college group over there, and it was lovely. We were thrilled to be invited. Every now and then we get the opportunity to, like, zoom into a classroom and talk about paleontology and science communication, and it is tons of fun. It's so great. And the students had great questions. So it was wonderful. And thank you. Thank you for the letter and the stickers. Yes. Next up is we have some recent and upcoming events. Recently, we celebrated our nine year anniversary. We did a live stream and you can find that archived on our YouTube. So if you want to see any of the news and announcements that we talked about there for the upcoming year of the podcast, check it out. we announced some upcoming plans some upcoming projects some upcoming changes uh we won't reiterate them right now partially because you can go listen to it in there and also a second because as of this recording we haven't done it yet so i don't know what we said no i know we're planning to say but i don't know if anything changed we will have had said some interesting things as far as upcoming things are concerned coming up soon is the first episode of Poke-E, our special Speculative Evolution series. Poke-E will be releasing Saturdays, five episodes, five Saturdays, starting the first Saturday in February, a la Spook-E. Each episode, we will be turning our speculative evolution gears toward legendary Pokemon. It's so much fun. I'm so excited to put these out. They were so much fun, so definitely check in and share your thoughts about Pokemon's speculative evolution. One more big thing before we get into the news. As usual, the world goes on outside of this podcast, and every now and then we see an opportunity to use our podcast platform to shout out some people doing some good work. This episode, we want to give a shout out specifically to the Women's Foundation of Minnesota, which does a whole bunch of community-focused efforts for really good causes, including the Immigrant Rapid Response Fund that directs funds to organizations mobilizing and organizing communities to support and protect immigrants, provide human services to immigrant communities under attack, and provide legal services. We'll put a link down in the episode description. If you're able, check it out, learn about what's going on, and potentially lend some of your own support. Also, there's tons of other mutual aid organizations in Minnesota and in Minneapolis that are very active right now for helping communities deal with the difficulties that are going on in that part of the country. As we've expressed before, in difficult times and especially in times where the people who are supposed to be supporting and protecting us aren't doing that, we have the responsibility and the great opportunities to support and protect each other. Absolutely. So check that out. Support if you can. Share the link and take care out there, everyone. And then on a much lighter note, over the history of the podcast, Will and I have had the glorious opportunity to mispronounce words from all over the world. Oh, no. And I don't know that we've ever quite messed up Danish before. So this is – apparently the site isn't called Stephen's Clint, and our Danish listeners got a delightful laugh out of that, most likely. In Denmark, I am told by Sarah on Patreon – thank you, Sarah – that it is pronounced more like Stone's Clint. Oh, okay, okay. As Sarah said, who's Stephen? And I was stuck on, how did we miss a Clint? No, no, no. That one I nailed. That one, got it. 50% absolutely flawless. It was a stumble in the first half. It's Stone's brother, Stephen. Yeah, same last name. I know a Stephen Clint. Well, with our announcements done, we can now move on to our first section, the nude. Every episode, we like to gather up some recent scientific news, research studies into biology, evolution, and paleontology, and discuss them here so we can all stay up to date. But for our first bit of news, we have something special, don't we? We have guests. We have some news guests. So we're now going to cut to a discussion with Ben and Jacob of Let's Botanize to talk about their science communication efforts and the news part, their new book that's coming out. Yet another thing we haven't actually recorded yet. So, Will, in the edit, put that in here. Put that in right now. Hello, Ben. Hi, how's it going? Hello, Jacob. Hello. Welcome. Thank you both so much for being here. You have a book to talk about, but before we do that, please introduce yourselves for our audience. Yeah, absolutely. So we're both here as part of the organization Let's Botanize, but I'll introduce myself first. I'm Ben Goulet Scott. I work at Harvard Forest, running education programs out there, getting undergrads involved in ecology research. And in the evenings and on weekends, I'm one half of Let's Botanize, an educational nonprofit working to spread curiosity and appreciation of plants. Yeah. And I'm Jacob Suiza, the other half of Let's Botanize. During the day, I'm an assistant professor of botany and evolutionary biology at the University of Tennessee, Knoxville, where I study the evolution of plant form and function with a specific focus on the ferns, an amazing group of plants. And like Ben, in the evenings and on the weekends, on Let's Botanize. Great. So tell us what Let's Botanize is, what that's all about. Yeah, so Let's Botanize is first and foremost an educational nonprofit. It is, we are incorporated as a formal 501c3 with sort of many stacked missions, right? The sort of most narrow, the narrowest mission, if you will, is to spread the hobby of botanizing, which is a natural history hobby, sort of like birding, right? But for plant. And we sort of scale up from that, right? We think that the sort of broader mission of Les Botanized is to combat the climate and biodiversity crises through botanical education. And there's a sort of logical link there, right? Because plants are the foundation of all life on land without them. Life, as we know, couldn't exist. A care for plants is a care. Right. So so this idea of sort of linking an appreciation for these organisms with sort of stewardship, kind of the broad, lofty mission. But the bread and butter of Let's Botanize is science communication. So the way we spread the hobby and sort of attack this mission is by making short format video series and educational photo posts, primarily on social media. But we're diversifying the sort of ways we interact with people. And we actually just wrote a book, which I think is sort of the focus of our organization right now. Yeah. So this episode that this piece is going to be on comes out the last weekend in January. And I believe that means that the book will already be out by the time that people are hearing this. So tell us about the book. What what what are people looking for if they are looking for this book and what can they expect when they open it? Yeah. So the book is called Let's Botanize and it has a subtitle, 101 Ways to Connect with Plants. And it's the sort of the elevator pitch of the book is it's 101 short exercises to sort of tune your attention to looking at different aspects of plant life. So it's an exercise or a prompt, we call them. A prompt might be, can you find the veins in the petal of a flower? You know, that'll just get you looking, looking close at a flower, maybe realizing, hmm, I got to buy a hand lens and really take a close look at these things. But there are sort of exercises like that. And then after the prompt will be a few paragraphs of us writing about the biology, you know, maybe the development of petals or the evolutionary origin of petals, that sort of thing, expanding on sort of the botany behind those observations that you're making. Yeah. Yeah. Yeah. And the sort of overarching idea behind the book, right, is I have right here to sort of like give people a tangible way to sort of get into the hobby of botnizing. Right. So it's it's literally, as Ben was saying, sort of set up with these 101 prompts and you can sort of flip to any page, read the exercise, read the prompt, go do the prompt and then understand a little bit more about like what you're doing. Right. Why do we look at plants? How do we look at plants? What are the underlying processes, patterns and perspectives that we sort of take when we look at? Yeah, I really appreciate that approach to you. You sent an excerpt of the book for us to look at and these prompts like, can you find a plant growing on another plant? Can you find a climbing plant? And it really makes me it makes me remember a conversation that was had on Leave it to Us, our spinoff podcast, where our friend Ali, both Ali and Nora were asked for advice on how do you start understanding plants and how do you start getting to the plant? into them. And the advice that Ali and Nora both agreed on was you have to go out and look at plants. Yeah. You like pick a plant, pick a plant to follow, pick a thing to find. And this book feels like that advice in a book. Yeah, that's exactly right. It feels like if I had this book, not in my pocket because it's, you know, it's a full-size book, but like in my backpack, it's kind of like having a botanist friend to point out a cool thing and then explain the science behind that cool thing. Yeah, that's exactly the goal. Sometimes we joke that what Let's Botanize is trying to do is be the unofficial PR department for this hobby of botanizing, which was really popular in the 19th century in England, especially. But if you look at the Google word graph, the word botanize, we didn't make it up. It was peaked in popularity in 1830 or something like that. And we're trying to bring it back. You know, it's just the natural history hobby. I think it, you know, we saw like birdwatching have this huge boom in popularity during the pandemic, especially. And a lot of plant hobbies had a boom at that time to gardening, houseplants, foraging wild foods and botanizing. We think it's just this layer of another hobby that can be added on top of any of those. Yeah. And the other thing is, you know, sort of where to harkening back to your point about how do you start? Right. Like botanizing is all about active observation. Right. Which I think we can we can make the analogy to active listening. Right. It's I think we often take for granted, like, you know, you see, but you don't always observe and you don't always observe actively. And so what we really try to do with this book, as well as with the organization is, you know, guide, help guide people right towards that idea of active observation. Because once you start sort of taking time, actively observing plants, I mean, that's that's botanizing. You can learn so much from it. But the other thing that's I really like how you framed it. It's like having two botany friends in the field with you. That's exactly like when Ben and I wrote this book, what we were trying to do is like deconstruct how we think about plants. When we go in on a walk in the woods and grab a leaf, you know, and look at it with our hand lens or look at a flower closely or look at the bark of a tree or smell a leaf or crush it up and taste things. You know, like we tried to ask ourselves, like, what is going, what's the algorithm that's going through our mind when we're trying to ID something or when we're trying to understand, like, you know, what could this trait be adaptive for or how did it evolve if it was sort of drift, right? And that's what we tried to do. We tried to take that mental algorithm and put it into text with this book. Yeah. I also really appreciate that talking about like trying to get people to observe and the book being the PR for botanizing that the book is very engaging to look at that. It's got really nice images. It's not it's not just like a technical field book where it's picture description picture. It's engaging and it reminds me of like the animal books I got as a kid that have the info, but also are just full of cool pictures to where like I could absolutely see a, you know, a young person who likes plants or is getting into it just flipping through to look at the pictures and then on passes through reading a bit more each time and picking it up. And I like that it's that kind of book. Yeah, I guess it is a great point that we haven't addressed. but do you have a specific audience in mind right this isn't like a kindergartner's book right this is for you know slightly older readers but do you have sort of a target demographic or age range it's a great question so one thing about botany well it's true of all the sciences but it seems like botany in particular just love to come up with new vocab words cannot stop themselves so we we wrote a whole glossary in the back of this book. So you don't need to come with, you know, knowledge of the vocab already. And, and we're trying to, you know, have it be certainly accessible to high schoolers, maybe like precocious middle school or even, you know, trying to get into it. And especially because it is really heavily illustrated with photos. You don't need to necessarily read every word to get, I think, something positive out of it. But probably, you know, solidly high school and up. And then yeah, and anywhere, not anyone who's just curious to learn and or not even just learn you might already know a ton about plants but it's like a workout guide you know let me try yeah yeah and that's and that's one other thing about the book is it's so it's definitely as ben said geared towards yeah either precocious middle schoolers and up but even people who have advanced degrees in in botany this this book is for them as well right because it's like these prompts are they're evergreen maybe to use them on um right like even like you can sort of visit them not only different times of year depending on the prompt most prompts we tried to think about like okay in the winter in the temperate region like you know you're not going to be able to uh well depending on the plant you're not gonna be able to look at the petals of a flower and it's like witch hazel or something right but you know like we tried to really make prompts accessible across across seasons across climates across uh sort of geographic regions but you can also visit them not only like in a short temporal time scale but sort of a much longer one, right? Like on your botanical journey, you know, you might read prompt 42 when you're just starting out five years later, you know, finished your master's degree or your PhD and you read prompt 42 again with a whole different perspective, right? So they sort of like live on in different ways. Maybe you bring the book, you know, when you're going to the field in another country or on a vacation, you do a prompt in a different place with a plant that you've never seen before. So they're evergreen. Yeah. This is the kind of book I think that, like you were pointing out, people of basically any age could enjoy this. I know we have a lot of listeners that this feels like the kind of book that they would really like. This also feels like the kind of book that starts somebody on their scientific journey. Like this is exactly the kind of book that you're like, I remember when I was 12 and I had this book and I would walk down the street and I would look at all the flowers and I would look at the leaves. It is that kind of like scientist's companion product, which is very, very cool. I appreciate that a lot. Yeah, that's if we could have that effect on someone, it would be incredible. Yeah. So I have a friend who she's just finishing up her master's degree at University of Edinburgh. But I was talking to her and I realized she joined the Gesneriad Society at the age of 13. So Gesneriad is a group of very charismatic flowering plants. And so she she joined the society at the age of 13. Right. And so like I think about her at this young age, like joining this flowering plant society with a bunch of probably older people who cared a lot about plants. And like, yeah, maybe this book is for someone like her at that age, right, who was just really into plants. And this could sort of kickstart their journey. Yeah. Speaking as a person who finds plants interesting but does not even know where to start, I would find this book very helpful. Because this book, as a person who professionally sits inside and reads about things, the book that goes, look for this specific thing. Here's a picture of what it looks like. And here's what it means. That's awesome. That's so incredibly helpful. Yeah. And that's one thing. We really tried to, you know, there's sort of multiple dimensions of the book, right? There's, as you were pointing out, the visual aspect in the photos, most of which are actually ours. We both do a lot of macro photography, but there's also there's the action, the prompt of going out and doing it. And then there's that like there's that nugget of information about a paragraph of, you know, it's it's it's evidence based. Right. This is sort of it's it's rooted in scholarship. It's it's real academic information written in a very digestible form that anyone can understand. So we didn't sacrifice. One of the main sort of points of teaching philosophies of let's botanize is not to sacrifice sort of rigor for accessibility. But everything is always accessible. We work really hard to try to do that. So you definitely get even if you look at the picture, that's one thing. You do the prompt, that's another thing. You read the paragraph, that's another thing. And you're definitely going to learn some information from it. Yeah. Also, good thing about plants is that you can botanize anywhere. You can botanize from your desk, eating a banana. What the heck is this thing? Different layers of the fruit and everything. You know, we're just around plants all the time, whether you are conscious of it or not. Well, and I like because there is an excerpt early in the sample you gave us saying that, like, it's easy to see it as the stage. Yeah, that plants are just the background that animals are acting in front of and that this book is really trying to say if you just pay attention, there's a bunch of weird, cool, neat things that you might notice that you were just scanning past. You know, just just not even registering that you're walking by every day you go down the sidewalk or in your backyard or wherever it is. Or in your kitchen. Yes. Yep. Your houseplants. Yeah. We often say that no shade thrown on other natural history hoppies. We love them all. But we often say that botanizing is the most accessible. Right. Plants are everywhere. They don't move. For the most part, we're all actually quite familiar with their morphology and anatomy. Right. Think about wood and think about when you're cutting up a tomato or a cucumber or eating a salad or eating a fruit. Right. Like we understand different botanical parts sort of they're inexorably linked to our to our daily lives. And so, as Ben was saying, right, you can botanize. Yeah. And a pristine forest, you know, primary forest with, you know, huge trees and such. But you can also botanize on your sidewalk. You can botanize in your kitchen. You can botanize, you know, at your desk looking at the grain and the wood. Right. It's a very accessible natural history hobby. Yeah. So as you mentioned before, the book is sort of the big focus of Let's Botanize at the moment. Just briefly, what else is Let's Botanize working on? Are there any other things sort of in the works? What's coming up for Let's Botanize? Yeah, great question. So we keep doing our social media thing for now, releasing videos and photos regularly. We try to hit a weekly schedule with those. And another thing that we're really excited about right now is last, a year ago, last spring, we started an internship program. So trying to sort of take some of the things we've learned and developed in terms of doing science communication and have college student, one or two college students join us remotely as an intern and, you know, work with us, see behind the scenes a little bit and learn a little bit about our approach to science communication. That's awesome. I think one other thing we're really excited about is diversifying the way we interact with people. And so, you know, I think we all recognize the fragility of social media platforms for a variety of different ways. I mean, they're great, right? They've sort of created our organization in some capacity. And I think a lot of other science communicators, you know, can relate to that. But they're also, yeah, they're ephemeral and they're your beholdence to these, you know, large corporate fill in the blanks, whatever you want. and so we're really trying to think about what are ways that we can sort of diversify the way we interact with people so the book is a physical one and we're trying to write monthly blog posts and we're also just trying to think about cultivating creating botanical tools for people to sort of go out and do botany so there's a variety of different things we're thinking about and it's an exciting time I think for the organization Wonderful for all of our listeners who are intrigued and want more where can they find you let's botanize and where can they get the book yeah so social media we're on instagram tiktok youtube at let's botanize is our handle botanize with a z the american spelling the brits will do the s sometimes but yes and you can also check out our website is www.letsbotanize.org find all of our stuff housed there. And the book, I think it's available on all sorts of different platforms, certainly Amazon. You can buy it directly from the publisher, Hachette. But if you just search Let's Botanize 101 Ways to Connect with Plants, it'll pop up. Fantastic. We will find one of those links and we'll put it down in the episode description for our list. We'll put your website link down there. And if there's a convenient link for the book, We'll put that down there, too. Conveniently, the book and all of your efforts are under the exact same very memorable title. So listeners, just Google Let's Botanize with a Z and you will find it. You'll find it all. Ben, Jacob, thank you both so much for joining us. And congrats on this new book. We hope that it we hope that this sincerely is a lot of young people's first. Maybe even if not their first. I think that this book is going to carry some people into science in a really significant way. Absolutely. Thank you guys so much. I had the thought that this should be bundled with the David Atborough's Life of Plants or whatever that was. That means a lot to us. Yes. It feels like if you watch that documentary and then someone hands you this book, you're primed for this to be perfect. This is what you need to do is to put together a bundle that's that documentary and this book and then leave it to us. Yes. And it'll be a little collaborative plant bundle and we'll be here. Be a botanist. That's great. I love it. I love it. And some broccoli or something to stay healthy. It's wonderful. Thank you guys again for joining us. Congrats again. Listeners, it's Let's Botanize on social media and also the book. Find the link down in the episode description. And go enjoy the plants in the world around you because they're out there, whether or not I personally am paying attention to them. Absolutely. Thank you guys so much for having us. It was a lot of fun. Thanks for having us. Thanks again to Ben and Jacob for coming on to talk with us. Hey, we know we got a lot of plant fans in the Common Descent audience. Check them out at Let's Botanize. Yeah. And now, David, what's your news? I've got news about fungi, but maybe not. Interesting. Okay. This is research. This is the latest in the ongoing investigation into what exactly Proto-Taxides is. I heard. I got a glimpse of this. This is research by Corentin Leron et al. in Science Advances. We'll put a link in the episode description to an article on Science Alert by Mike McRae. Prototaxites is a group of very famous organisms that lived on land during the late Silurian into the late Devonian. They were part of the very earliest land ecosystems. And the reason that they're famous is not only were they diverse and widespread, they were the largest land organisms. at all for most of that time period. At their biggest, they were tree-sized. They were many meters, either tall or long, depending on what interpretation you're going with. We talked about Proto-Taxiides in our fungi discussion in episode 200 because that has been for a long time the best guess at what Proto-taxides actually is. But this has gone back and forth quite a bit. Proto-taxides was sort of tree trunk shaped or tree root shaped. It is clearly eukaryotic, right? Completed is multiple, a multicellular organism. The body is composed of different types of tubes that variously branch and contact each other. They have cell walls. so this is eukaryotic multicellular originally it was identified as a type of plant prototaxides me i think taxides is you or something But chemical studies isotope studies of the fossils have consistently found a mismatch with photosynthesis. That the isotope, the chemical composition does not match a photosynthesizing organism. Other suggestions have included that it might have been like a giant lichen with multiple symbiotic organisms working. But there also hasn't been any definitive evidence of a different organism in these specimens, even in the really nicely preserved specimens. And not an animal, both A, not shaped like an animal, but also it has cell walls, which is the thing that animals don't do. So having ruled out all the other options, that leaves fungi. And prototoxides being made of tubes, having cell walls, those are fungal characteristics, right? It's compared with hyphae. We talked in the fungus episode about the suggestion that it might have been like these root-like structures that we sometimes see formed among modern fungi. But this has been debated for a century, more than a century, with various different studies finding reason to group it with various different groups of fungi, or as a completely separate group of fungi, or as not a fungus at all. This study is the latest deep investigation into the composition and anatomy of prototaxides to try to sort some of this out. In this paper, the researchers did a close examination of three specimens of prototaxides tete from the famous Rhiney chert, excellent preservation of plants and fungi. These are, like most prototoxyde specimens, little fragments, little chunks, including one new one that is particularly large. It's several centimeters in size and well-preserved in three dimensions. Taking a close microscopic look at these specimens, the researchers identify them being composed of three distinct types of tubes. So the bundles, the sort of hyphae-like structures. They exhibit banding regularly across the tubes, and there are these collections of dense bundles of tubes, both of which are, the authors point out, are similar to the overall structure that we see in things like lungs and capillaries. the sort of shape you see in structures that are for the exchange of gas or nutrients or water that these might be specialized nutrient mobility structures in proto-taxides which they point out might be part of why they were able to get so big that they had this sort of sophisticated network that same this is around the same time that plants are evolving vasculature which allowed them to do the same. However, they also point out that these structures are not known in fungi. This is not something we see in fungus. Also, they point out that the microscopic and chemical composition of all these different tube structures is the same, which suggests they are all one organism, that there is no evidence here for a symbiont mixed into here for that lichen idea. So all of that, interesting insights into just the anatomy, the lifestyle of Proto-Texites. They also did a chemical analysis basically to figure out what molecules and elements is Proto-Texites made of. Yes. What's extra exciting about this is they were able to compare it with living, you know, groups of organisms. But also because the Reine chert has tons of fossil fungi, like confidently identified fossil fungi, they were also able to compare the chemical composition with fungi fossilized in the same environment. Yes, so that even if the fossilization process modified or shifted these chemical signatures, we should be getting the same modifications on these identified fungi. Yes, exactly. They also looked specifically for certain biomarkers of fungal chemistry. They looked for things like perylene and chitin, which are, in the case of chitin, ubiquitous. And that's one of the defining features of fungal composition. And as you just mentioned, they did account for what chemical evidence would we find after fossilization, right? What are we – we're looking for the products of these things. And they found none of it. They did not find a comparison between the fossil fungi and prototoxides. They found no chemical evidence for things like chitin, which does feel like kind of a big deal. That's – yeah. Fungi have chitin. That's one of their things. Yes, absolutely. And they took this chemical analysis and ran it into a statistical program. Basically, like, here's all the chemical information, put it into a statistical program with similar information for modern fungi and fossil fungi, plants, bacteria, and so on. And the analysis consistently separated prototaxides from everything else. not fungus not plant not bacteria none of those so as the authors put it based on these results prototaxides is best interpreted as a previously undescribed independent and extinct lineage of complex multicellular eukaryotes whoa which is to say not any of our known categories yes something that we do not have an example of, not a member of a group that is no longer around, a group we have no example of today. Yes. Now, it is important to point out, this is the latest study. This has been an ongoing back and forth for many, many years. There have been multiple prototaxides studies that have come out in the past several years that have linked prototaxides to various groups of fungi. So this certainly isn't the end of the discussion. This isn't like for sure this is some completely new thing. But it is pretty detailed evidence that prototaxides is something odd. Yeah, well, it feels like, no, we can't take this as the final comment on this situation. But it does feel like it might be fairly definitive on whether it's a fungus or not. That classic interpretation, they did not find any inkling of support for it being a fungus. So that at least, it's not an answer for what it is, but it might be an answer for what it isn't. Right. And it's possible – I think they did talk about it in the paper that, like, could this be just a really bizarre fungus? And they – if I remember right in the paper, they do – and I'm paraphrasing, but basically it doesn't – that's a lot of change to basically lose all of the defining attributes of the fungi. Could it be an early branch off the fungus lineage? This – the way that you put it is very astute. This doesn't actually answer what it is, but it does help us figure out what it isn't. And it doesn't seem to be a fungus. Yeah, my best guess, and I thought of this back when you're talking about its sophisticated tube networks for moving either air, water, or materials. And with it now seeming like it is potentially some unknown category of life that we are not familiar with, These were obviously Tyranid capillary towers that were used on early Earth, because I don't know who else they would be. And then they left, and they aren't in the fossil record ever since then. So they came down, they went, nothing tastes good here yet, we'll come back. That's so crazy. For any of our listeners who don't know what Tyranids are, we'll mean Zerg. Yeah. So that's what that does. Elasphemy. Elasphemy. So this is it's a fun update to sort of a state of the debate with Proto-Taxiades. As of this month, the most recent evidence is weighing in the direction of Proto-Taxiades being neither plant nor fungus nor bacteria. And if you're wondering, what does that leave? Great question. Yep. Yep. Yep. Which is like we've gotten questions like that before of, you know, could there have been multiple origins to life? Could there have been groups, you know, like there's groups, we have questions like that with the Ediacaran biota of were you predecessors to animals or were you something else that died off before animals ever showed up? And we don't have any example of that form of life. That's definitely something that can have happened, especially in those early years of Earth. It's just very hard to confirm that since we don't have any evidence of what that would be. Well, and if it is a separate branch of eukaryotes, then presumably it would have originated around the same time as the other branches of eukaryotes, which was 500 million years before this. So there should also – this is the other thing that makes prototaxides mysterious is there are several identified species of prototaxides, but then there's not a lot else like prototaxides. There are some other, I believe, like Silurian things that have a similar structure. The nematophytes, I think, is the sort of collective group. But outside of that, we don't have a lot of other prototaxides-like things. So for the moment, it's just sort of floating in the middle of nowhere on the family tree of life. Insane. Insane. Well, my news is not nearly as trippy as that, but is funnier to imagine. which is that according to this research the giant fossil kangaroos that once lived in australia might have been able to hop oh yeah this is research by megan jones et al in scientific reports and the article is a press release in sci.news so kangaroos you might have heard of them. Very famous hopping mammals, the largest hopping animals alive today. The red kangaroos can get up to be like 90 kilograms or 200 pounds. So that's the size of a grown human adult. That's my size. But there were giant kangaroos in the past. Even gianter kangaroos. Truly humongous. In the Pleistocene, there were giant members that sometimes doubled the size of today's kangaroos, with some reaching estimated sizes of 250 kilograms or 550 pounds. These have often been assumed to have been non-hopping kangaroos. Just too big. They seem like they're very heavily built. And it's just been kind of said that, yeah, these would have evolved out of being able to hop. And the studies that have suggested this in support of this idea, looking at the body, the anatomy of today's kangaroos and scaling them up, said that the cutoff for hopping ability would be 140 to 160 kilograms or 300 to 350 pounds. Yeah, we talked about this in episode 193 about hopping, that it has been, that has been the general consensus. There is an upper size limit to efficient hopping. Once you get past a certain point, it just is no longer considered energy efficient to jump around. Absolutely. But these studies were scaling up today's kangaroos to the sizes of the giant kangaroos. And it's been pointed out that the giant kangaroos are not shaped the same as today's kangaroos. They have different proportions, different anatomical features. So this study wanted to look at the actual anatomy of the giant kangaroos and ask the question, could these bones handle the stresses of hopping? Are they robust enough? And could they support ligaments strong enough to be elastic enough to support the hopping and bouncing of those movements? So they looked at the hind limbs of 94 modern and 40 fossil specimens, including 63 kangaroo and wallaby species. For each one, they used published estimated estimations of their weights and the length and diameter of the fourth metatarsals, which are the main hopping foot bones. They wanted to calculate whether or not they could stand up to the strains of hopping. They compared the heel bone structures in the giant and modern kangaroos to see how they stack up and looked at tendon attachment sites on the bone to see what that suggested about the robustness or the size of the tendons attached to those bones. It sounds basically like an automotive safety investigation where you're like, all right, let's give this thing a once over and make sure that it can handle the stresses of operation. Yes, exactly. And what they found was, first off, that the giant kangaroos are shaped quite differently from modern kangaroos. They have a number of features that stand them out. And that their metatarsals, the foot bones, were robust enough to resist the forces. So they seem to be strong enough to take on hopping and that the heel bones have attachment sites for tendons large enough to resist the loads that would be put upon them while hopping. This suggests that the back legs of these giant kangaroos could stand up to hopping, that they would not snap or strain or break under the repeated impact of hopping. Now, does this mean they were hoppers? That we can't say for sure. It is unlikely that they were regular hoppers because even with all of this at that size, and as you said, they would be inefficient energy-wise. They don't get the benefits of that long-term hopping that today's kangaroos get for that long-distance travel, but it is possible that they could have used it for sporadic hopping, so more like a kangaroo rat to avoid predators or something like that. That hopping could have been for short bursts to get away from danger and not long distance travel as much, but still a viable option for these giant kangaroos. We've talked a bunch in the past about one of the big conundrums in paleontology, the question of could an ancient animal do something and would it do that thing? Yes. And this is one of those scenarios where the general, sort of the conventional understanding has been that these animals couldn't hop, that it was just too stressful a motion for them. Well, it's kind of like elephants can't jump. Like an elephant cannot leave all four feet off the ground at once. They're too heavy. No matter what they do, they will never get all four feet off the ground at the same time. Right. Without the assistance of a cliff. Yes, exactly. But this research seems to suggest that that part, that these kangaroos could do some hopping potentially. So the next question becomes, did they actually do it? Yes, exactly. And so I propose to Australian Pleistocene paleontologists that you find some footprints. Yes, yes, yes, absolutely. We talked about footprint fossils of hoppers in episode 193. 193, and if I remember correctly, I don't believe there are any known kangaroo trackways, like fossil hopping trackways. Not that I've ever heard of. So someone someday is going to find a trackway of giant kangaroo feet. Well, and it feels like they'd be very identifiable because some of these giant ones also had like just one big toe. Like they had reduced their toe bones down. So you would be able to tell who it was. Those trackways will either be alternating left and right, or they will come in parallel pairs. Mm-hmm. Mm-hmm. Yeah. It's very interesting. Well, and, like, they note things, like, these bigger tendons are safer, but they store less energy. So it still is this interesting tradeoff that you would have still gotten bounce, but not as much bounce. You don't get the return on investment that the bouncing of kangaroos gets. Which is the iconic thing about kangaroos, the shape of the ankle and the foot allows them to preserve that energy and that momentum. It feels like when you skip. Yes, exactly. You're skipping, you're carrying your momentum into each step. Yes, that they have to bounce the first time, but then the impact of landing sets them up for the next bounce. Yes. These giant ones would not have gotten as much return each time they landed. But it's still possible that if they were ambushed by a predator, they might be able to sproing away to get away from that attack. Which also, a 500-pound, and these were like seven or eight feet tall, like standing up on their hind legs. That thing just Hulk jumping away, horrifying. But also adorable. I want to see it. The image in my head was of the thing what kangaroos today do where they jump up and then kick each other. Right? When we thought these guys couldn't jump, it felt safe. Just don't get punched. But no, if they could jump, that's a lot of fun. For cow! This is Australia. All right, add that to our paleo fighting game from the Q&A. Yes! Just thundering giant kangaroos with a kick move. Yes, that would be so cool. And with that... Speaking of giant weird animals... As I said, and to get even stranger, we will now discuss the Calicotheers and what is that? So, Calicotheres are one of those interesting fossil groups that I feel like are medium famous. Yes, I would agree with that, absolutely. Yeah, like, they are not some weird, super obscure group, like, you can find pictures and representation of them in museums quite regularly. They've been in documentaries. Yes, but they are not like the top popular fossil mammals. And part of that's because they are quite mysterious and somewhat rare. Yeah, they're a little bit too weird to be famous. Yeah, and there's a lot, there's still a lot about them that we don't know. So they are this kind of middle ground, have a long history in paleontology, have some notoriety, but there's still a bunch of scientific questions. And they are still most people. When I mentioned to the average person about a click of here, they don't know what I'm talking about. Right. Even people who are interested in paleontology. Yes. Like I wouldn't be surprised if a bunch of our listeners are not immediately familiar with this term. So, Will, I'll ask the question that I'm sure many of our listeners right now are wondering. What's a Calicather? Also, for the listeners out there, Calicather and Calicather, I've heard both pronunciations. Yes. Yeah. We will probably waver back and forth. Yeah. My default is Calicather because that's how I learned it. And both make sense. But, yeah, when I say it out of reflex, I go with Calicather. So this is a group of paracidactyls. So your odd-toed, hoofed animals, horses, rhinos, tapirs, these are members of that group, but they are not hoofed and are very strange. They are big plant eaters, you know, big-bodied plant eaters like the others. They have odd toes. They have three toes, but instead of hooves, they have claws. Yeah. And not just, like, technically prominent claws. Yep. Like, claw claws. Yeah, like, these are notable claws, and we'll talk about how notable they were as they were discovered. And they have very odd proportions. They have these longer front arms, and some of them have really long front arms. Mm-hmm. So they are these kind of bear or gorilla-shaped cousins of horses and rhinos with clawed feet and hands, but still were plant eaters. Very unusual animals. Yeah, they're often, you'll often hear when people try to explain what they are real quickly, and I think we've probably done this on the podcast, is refer to them as gorilla horses or sloth horses. I actually pulled up a picture for my own reference of a skeleton of a Calicather. And it's so – my brain wants so badly to interpret this as a horse because it looks – it's almost there. And if I scanned over this really quick, I'd probably go, horse. But the more you look at it, the more is wrong. This is a not horse. The skull's a little bit off to be a horse. The legs are just, like, they're just, even the slope of the back, the whole, it's just, it's a twisted horse. Yeah, and the experience you just went through is very much what the scientific history of these animals is like. This, I think, is maybe the thing that is most famous about Calicotheers. If they are famous, it is less for their own actual features and fossil record and more for how the scientific community has responded to them over time. It's kind of like hallucinogenia, the famous Cambrian fossil, which is a really cool animal that is most famous for confusing scientists. Exactly. Yeah. These have a very sorted history of how we've come to understand them because they were so unlike anything we had found at the time. Yeah. It also is because their fossil record is not great. It is not a particularly robust fossil record. They have a very long fossil record. They showed up in, like, the Eocene and were around until the Pleistocene. So a good 50 million years or so of fossil record. And they were wide-ranging. There are remains found in Asia, Europe, North America, and Africa. So they ranged across the entire northern hemisphere and dipped down into like Central America and Africa. Yeah, so about as widespread as horses. Yes, exactly. So we have the setup for a robust fossil record, and yet most remains are very fragmentary. So like just a few elements, some teeth, some claws, maybe a jaw, maybe some limb bones. There's very, very few complete specimens, and even most of those complete specimens are very crushed and in poor condition. So most groups within this overall lineage, we do not have a full body representation. So there's a lot of gaps in the fossil record, which made historically it very hard to figure them out. And even still today makes means that there's a lot of questions that we really don't have good answers on. So one of the things that was difficult to figure out was who they related to. Nowadays, we're pretty solid that they are parasidactyls. So odd toed umulets, they who they are most closely related to within that group has been debated and is not fully confirmed, fully decided upon. Mm-hmm. Generally, they are typically placed within a clade called the Ankylopoda. This also includes some of their relatives, the Lophiodontidae, which are a group of mammals from southern Europe during the Eocene. They've been argued whether they are closer to horses, the Hippomorpha, or closer to Brontotheres, which we talked about in the rhinos episode. Mm-hmm. Episode 129. Some have considered that they might have a mix of characters between Hippomorpha and Seratomorpha, which includes Tapers and Rhinos, and that they might be in their own lineage next to those two. So they're somewhere within Perissodactyls. Somewhere within there, some have divided their characters into primitive and derived characters that put them closer to the seratomorphs if it's the derived characters or closer to the hippomorphs if it's the primitive characters. Sure. So they seem to have kind of a mix. It seems like more often than not, things tend to lean that they are closer to horses than not. So they have some features that the Ceratomorphs lack in general and that almost all Calicotheres have. One specific one of the molars that is pretty consistent. There's still a few that don't have this feature. So somewhere within there, probably leaning toward horses. But how close is probably still going to be debated until we get even more nice specimens. Yeah, that kind of confusion often happens either when you have a lineage that is ancient, right? This is an early split, so it probably split at a time when the horse and rhino lineages had not become very different yet. Yes, exactly. technically it's closer to one than the other, but at the time when that divergence happened, there wasn't much differentiation. And in this case, we have fossils of them back to the Eocene. So, Calicotheers are about as old as horses and rhinos. This kind of condition can also happen if you have a bunch of conversion devolution, where maybe they are closely related to horses, but have evolved a bunch of rhino-like features. And in this case, with Calicotheers, It's probably both. They are an early branch and they probably have been convergent in a bunch of features with their relatives. And you've got the other two factors that they're also a very specialized, like they're living in a very different way than horses or rhinos. So they've developed unique features that muddy the comparisons. Sure. The turtle problem. The turtle problem. And their fossil record is stinky. Yes. The bat problem. Yes. So we have this this combination of things that makes this a very mysterious group in trying to just pin them down clearly. So let's talk a little bit about how weird they are. I would love to. What are they? Generally, as we introduced, these are large bodied herbivores. So typically they're going to be pretty big. There are smaller members that go down to like the size of a taper or maybe sheep sized. But many species were like horse, bear or bigger. Like some of them got quite large. They have prominent forelimbs, you know, so big, robust forelimbs, a very horse-like head with a fairly horse-like neck. So kind of elongated necks. They don't have short necks like a bear. They have necks that come off the body a bit. There are three toes on each foot with claws on all the feet. So far clawed horse Clawed horse Then we get two separate morphs of click of the ear There are two subfamilies within the group There are earlier members before the subfamily split and we get into that later But the two main subfamilies are the click of the ear and a and a schizo theory. These two have notably different body types. The Calicothernae are the famous shape. And include Calicotherium, which is the name that led to this whole group. Sure. Full gorilla horse. Full gorilla horse. These have very long front limbs with very short back legs. Their front limbs are often like twice the length of their back legs. That's a wild, that's so, that's a wild shape for anyone. Yes, like that is extreme, period. That's, especially on land. If you're in the ocean, sure, absolutely. That happens a whole bunch. But for an animal on land, like gorillas are shaped like that, but they're shaped like that because they climb. Well, and that's the thing is like the only group where I can think of proportions that I see stuff like that regularly are apes. Yeah, but that's a whole different thing that they're doing. Because you have animals today like hyenas, right, who famously have that sloped back. And there are some dinosaurs like the brachiosaurs who have longer arms. But they're a bit longer. Yes. Generally speaking. Twice as long is nuts. Yeah. So very long, very gorilla-like front arms. They also had very mobile arms, mobile shoulder joints, very hook-like claws. They had shorter necks, so they seemed to be very gorilla-shaped in many, many regards. These are only known from Europe and Asia. They did not reach the Americas, so we did not get any of the really cool gorilla-shaped ones. We did still get some neat ones, but not the cool gorilla ones. And some of these still got quite large. Anisodon stood about one and a half meters or five feet tall and weighed like 600 kilograms. So like 1,300 pounds. So horse-sized. So horse-sized, but gorilla-shaped. Yep. Also, we do keep saying gorilla as the comparison, but I think that that does ignore the fact that it has claws, which is a really important, because gorilla horse does a lot of the job, but both of those do overlook the fact that all of its hands and feet have claws on them. Yep, yep. Though to reinforce that comparison, based off of the anatomy, it is likely they knuckle walk. Yeah, that I've heard, and I wasn't sure if that was going to come up in this episode as like, actually, we don't think that anymore. Yeah, it does seem that the Calicothyronae knuckle-walked, at least generally speaking. So knuckle-walking, dear listeners, is a behavior that is really a gorilla thing. I think chimps do it, but, like, I think gorillas and chimps are the species that do this. Yeah, yeah. Which is walking not with the hands flat on the ground, but with a fist, right? That you've made a fist or at least curled up the fingers and you're walking on the curled fingers. Yes, exactly. Which is pretty – I don't know of any other groups that do that because this has come up with early hominins. There have been some early human ancestors that have been suggested to knuckle walk. But some researchers have looked at that and gone, well, but knuckle walking is really distinctive to, like, gorilla-style life. And it might be unlikely that any other apes were even doing it. So if these guys were knuckle walking, that's bizarre. That is really interesting. The biggest indication for it is that it doesn't seem they would have been able to put their palms flat with the way the claws are curved. Sure. Well, because you're an ungulate that evolved claws. Ungulates, dear listeners, are the hoofed animals who walk on their tiptoes, like a ballerina on the very edge of the toe. So I guess if you're going to evolve claws, you have to bend those toes one direction. Yeah. Yep. And backwards seems as good as any, I guess. So they seem knuckle-locked. Now, all that being said, the other group, the schizothyrenae, don't seem to knuckle walk. Their claws were retractable. What? What? Yeah. I didn't know that. They seem to be able to bend them back. Maybe probably not as much as a cat where, like, they hid away, but enough to walk digitigrade on the flats of their fingers. So, I don't have a comparison for that. That's not, that's, so retractable in the way that like velociraptors claws are retractable, those big claws where they can lift it up. They're not necessarily, like you said, when you said retractable and I was like, like a lion? Yeah. Okay. Probably not that much. Right. But enough that they're not digging into the ground with each step that they can walk, you know, relatively flat footed. Incredible. Holy cow. Yeah. And that fits because this group is not gorilla-shaped. They are much more even in the length of their front and back legs. So still had prominent front limbs, you know, so they're not just equal, but much think more like a bear than a gorilla. And they seem to be much more for walking around on all fours and better at that. This group was also more widespread, found Asia, Africa, and North America. Okay. So this is the group that made it over here. It also includes the biggest members. Things like ankylotherium got up to be like two meters at the shoulder, six and a half feet. But things like moropus, which is one of the most famous because it is the most common known from here in North America. That's the one, the skeleton that I pulled up as a picture for a reference because we have full skeletons to look at. Exactly. This is one of our best known. It's also among the largest at 2.4 meters at the shoulder, 8 feet tall, and body mass estimated at over 1,000 kilograms or a ton. Here's the thing that I don't like that you've described, that the ones that are eight feet tall at the shoulder are the ones that don't have preposterously long front arms. No. Because if you had said the other ones were eight feet tall, I'd be like, okay, but like, but you know, they're like holding themselves up really high. No, these ones are bear-shaped. This is just a bear-shaped animal that is eight feet tall on all fours. Exactly. Yep. So it's like a tall rhino, basically. That size range is very, like, modern rhino-sized, but a tall version of that. Yes, precisely. So these had some big members, and they were shaped different in a couple other ways. They had longer necks and faces that sometimes hinted at maybe having mobile lips or even a long tongue. So they seemed to be much better at reaching with the neck and face than the other group. Cool. That is a thing that actually makes a whole lot of sense because especially like rhinos and tapers are very notable for like tapers have a trunk, but even rhinos have very mobile lips. Horses have very mobile lips, very flexible tongues for grabbing at food. So that I'm fine with. I'm OK. Accepted. All right. Now I'll make them weird again. Some of them, so we have enough of some species that it does seem like there's a good case for sexual dimorphism. Like we'll find very distinctly different sized members. So it does seem like males were probably larger than females in many species of chlycothera. And some have bulbous heads, inflated portions of the cranium. Most aren't like ridiculous. and chylotherium has slight inflation of the frontal bone of the skull to make kind of a dome, but tylocephalolonyx is the dome-headed callicother, has a very prominent dome, and only some members have it, so it seems like, again, this might be a sexual dimorphism thing, so some of them had dome heads. Huh. Yeah. So far, this seems like a prehistoric animal that was made up by a child. Right? And, like, you're just combining your favorite part. This is funny because I was actually, when we were talking about them being odd and kind of famous but not really understood very well, I was thinking about our conversation in episode 230 about pachycephalus sorts. Yep, yep. In a very similar way. This is another thing that's really interesting because, as we have discussed previously, we talked about this in episode 140, Arteodactyls do a lot of head ornamentation, horns and antlers and domes and stuff, but perissodactyls don't do it the same way, right? Rhinos are really the one exception, but even then their horn is a completely different thing than at the top of the head, the bony ornamentation. So that is really interesting to have a perissodactyl potentially headbutting. And this is found only in the schizothernae, so the all fours long-necked groups. It's not clear how they use these. It has been compared to the dome heads of pachycephalosaurs, but their necks don't show any evidence of reinforcement for head butting. So others have suggested that maybe it was more like giraffes, where they're swinging it at each other, but not at each other's heads. Sure, that would make sense. And it seems like in these two groups, at least, that it did evolve independently because they are not super closely related members. So it seems like this is a common feature that arised multiple times potentially in the group. Fascinating. What an odd group of animals. Oh, yeah, they are. That's so well. And it's, you know, it's funny because we have, you know, in our modern world, perisodactyls are three groups horses rhinos and tapers and all three of them are pretty similar in terms of their notability their diversity right like there's a few different major forms of horses there's a couple different major forms of tapers there's rhinos they're all quite distinct from each other so they feel like a real set of options kind of like a few years in my head have always been like, and then there were like these couple of weird fellas, but no, they were a diverse, widespread group that included multiple different morphologies and lineages that were doing different things. This was the other major group of parisodactyls. Yeah. For about much of the Cenozoic. And they lasted up until very recently. So they were doing quite well until the end, basically. Yeah, yeah, they're casualties of the megafaunal extinction, right? Yep, so they went out with a lot of other big mammals. They were one of the groups we lost in the megafaunal mass extinctions. Yeah, episode 25. And boy, what a loss. What, that's a real shame. Put them right next to ground slots. Yep, mm-hmm. In more ways than one, potentially. So on the note of how strange they are, this strangeness was a big factor in how we became familiar with them throughout the history of their discovery. They were discovered in the 1820s. So about 200 years ago, the first specimens were found, but they weren't found all at once. The first discovery was by Cuvier. Okay. Famous scientist discovered large claws, some large claw bones, and noted immediately how unusual these claws were. He compared them to other claws in the museum collection and came to the conclusion that the only claw that it is at all analogous with is the pangolin. Huh. Yep. That's the only claw it remotely resembles. Ergo, it must be similar, but much larger. A giant pangolin. A giant pangolin. There's a quote from the paper. It says, what size it must have been. And scaling up said that it would have been a pangolin about 24 feet long. Now, this, I am a little bit mad at Cuvier for floating this idea, which is awesome. Right? That'd be so cool. Like, I can understand why he wanted that to be the answer. That'd be awesome. And he was basing this off of a couple of lines of thinking. The comparison, comparative anatomy, also the laws of comparative osteology, which he was a proponent of, that we can draw conclusions from a lone fragment, and said what a great example this is of how we can draw a larger conclusion from so little, and was basing off this notion of harmony within nature. He'd already studied giant ground slots, and if there could be giant slots, why not giant penguins? Sure. It makes sense. Yeah. The next Calicotheer discovery was teeth and jaws by a German paleontologist, Johann Jacob Kaut, who identified them as a new form of pachyderm, an elephant. Yep, yep. Once again, a giant clawed elephant. Yeah, right? These signs just coming up with awesome speculative evolution. Though at this point, no claws, just teeth and jaws. So he thought, aha, that this was just some new form of elephant. A strange one, to be sure. He named it Calicotherium, the gravel beast, and described it the size of about a Javan rhino. He did discover claws similar to Cuvier's giant pangolin in the same material, in the same area, but he associated them with a different beast, Dinotherium, which is an elephant. Yep. But at that time, he was describing it as a giant mammal, kind of hippo-ish, marsh creature, and that it mixed identate, which is anteaters and the group that we used to think pangolins were in, and hippo-like creatures. So didn't actually have that categorized as an elephant at the time. So for quite a while, more material was being found throughout the 19th century, but they were either associated, if it was teeth and jaws, with Calicotherium, the gravel beast, or Cuvier's giant pangolin if it was claws. Interesting. And as more material was found, we also started to find leg bones. More species were named off of those. And Calicotherium, the crooked beast, was named off of some of those. Macrotherium, the large beast, was another one. These are now Calicotheers, but at the time they were grouped on one side or the other. These were named off of limb bones, I believe. And they were still placed with the Ididhants, the anteaters and pangolins, that they were somewhere in that large, clawed creatures. And people were still noting how strange they were. There's another quote that the jaw, fraction, and teeth were belonging to one of the most remarkable and aberrant pachyderms, that this was a weird elephant. Yeah. Yeah, really an instance of finding the best fit and knowing even then that this does not seem like a great fit. Yes, absolutely. This is super weird. If this is an elephant, this is a bizarre elephant. It wasn't until the end of the 19th century, 1880s and 90s, that scientists started to link the two because they were being found in the same material over and over. So often if you found one, you found the others nearby or in similar age material. They just weren't associated until a bit later. Multiple scientists came to this conclusion separately and kind of simultaneously. Like it was a lot of people started going, you know what? Maybe there's a reason they're always next to each other. Yeah, these teeth and jaws and these claws. Yeah. Coexisting. Exactly. And finally, in 1892, a compressed, mostly complete skeleton was found of macrotherium, showing the claws of macrotherium and the head of clicotherium. And they got the proof that they go together and the group of clicotherium was set forward. It's a fun, this has happened a number of times in paleontology, where you have, you finally found a complete specimen and you go, oh, and then you just get to merge two groups. Yes. And you go, actually, both of these groups, same thing. All pile them together. Absolutely. This kind of rocked the paleontology world at the time, because not only was this a major like update on, oh, okay, okay, reframing how we're looking at everything. But also it was an extremely unusual creature. Yes. One of the most bizarre fossil creatures we'd found at that time, you know, that we knew of. And it kind of shook, you know, the way people looked at things. A lot of people noting it as a textbook example against the Cuvier notion of correlation of parts, that all parts of an organism work together in a very concise way. this creature seemed like an affront to that of, well, but you've got plant-eating face, and then these massive claws. Those don't go together. So obviously that idea does not hold always. It also gained a lot of popularity just for how strange they were. There's a bunch of great quotes. One paleontologist called them wonderfully aberrant and as grotesque a creature as could well be imagined. And Osborne called them the most unique mammal of the Miocene period. Cool. So people were getting attention there, and it became kind of a cautionary tale. A lot of paleontologists at the time started noting it as, this is why we need to be more careful about over-assuming based off of limited data. Yeah. One professor of geology at Princeton, William Berryman Scott, said, The tale of these discoveries ought to put an end to the foolish notion that the paleontologist can reconstruct a lost animal from a single bone or tooth, but it will not. And so it became this lesson that was put forward of, we need to not do the click of theory again. If you've only got one piece, you don't have enough yet. And it was an important step. It's an interesting step in the process because that's a question that you still get today. People ask all the time. They're like, well, how can you tell what it is just from a single tooth? And the answer is we can if we have – if we already know this animal. Yes, exactly. If you find a T-Rex tooth, that's a T-Rex. We know that animal super, super well. But if you find a claw that doesn't match something that we've already found, you can't say, well, this claw looks the most like a bear. Therefore, this is a bear. And that doesn't work. And in this case, you found a claw before you had understood any of the rest of this animal. And nowadays, if we find a lone calicather claw, we can go, okay, that's a calicather. Because this is what their claws look like. But back in before we knew that, you can't make that kind of extrapolation. Yes, precisely. So this became kind of a major milestone in paleontology as a science as really being one of the big moments noting how we should go forward. Now that we had the whole animal and what they were, who they related to became the next big debate. we already talked about that who they're related to within pyrsodactyl is hard to tell at this point they were trying to figure out what kind of mammal it was period right if it was an anteater or an elephant yep those two were still up you know they interpreted as maybe being kind of a link between those two and most people did not go with that but some people suggested it sure Pretty early on, a lot of people rejected the pangolin and anteater-like traits as being coincidental, not because of who they're related to. Sure, just big claws. That they have similar claws, but it's not because they are in that group. But so many of the specimens were so poorly preserved, we did not have a really great way to identify them until more specimens were found. And then finally, a full study of Moropus came to the conclusion that the characteristics that link them to Parasidactyla are more dominant than any others, particularly that the skull is very similar and seem to be combining features of horse rhinos and tapers. Yeah. And that's something that, and this is another one of those great examples of the benefit of finding complete specimens, because if you look at the complete skull of a calicothera, that's a paracidactyl. Yep. Like, it looks like a horse skull. It's very, very clearly in that category. But until you have the whole thing to look at, it can be hard to know that. Yes. So the group Calicothyroidia was named in 1913. So finally, we had Calicothyres as a group. And findings of even earlier members, like Eomeropus, which seemed to have features even more similar to earlier parisodactyls, but still clearly a Calicothyre supported that evidence. And then the final bit of mystery was that many people noted that they dated to very, very recently. And so the question came up of were they still out there? So there was a time where it was held that there might still be Calicotheus somewhere. And, of course, they pointed to Africa. Sure, because that's where you put mystery things when you're a European scientist in the 1800s. So, yeah, a very roller coaster of a history because of both how strange they were, how they were discovered and the kind of fossil record they have. What an incredible time it was in like the 17, 1800s when people would find these skeletons and then wonder seriously if it was out there somewhere. Yeah, absolutely. I think I've heard this might be apocryphal. This might be, like, not a true story, but I do remember hearing the tale that Thomas Jefferson sent Lewis and Clark out across North America expecting to encounter ground sloths. Yeah. Or mannets or something. It's like, hey, we found these bones. While you're out discovering this landmass, while you're out exploring this untouched place that no people have ever been to, watch out because there might be elephants and giant sloths out and around. Yeah, and that's exactly how I heard is that it was a warning of, hey, just so you know, there might be things with claws this big. Just be prepared. and then all they found were grizzly bears and those weren't terrifying at all they found grizzly bears and bison and they said don't worry we know how to deal with these and then they did also they found humans and also they dealt with them the same way yep uh but yeah calicatherers have this really interesting footprint in the history of paleontology and serve as a really As you said, one of the most famous things about them is how misunderstood they were and how we overcame that and the lessons that paleontology took from that experience. Yeah. You got to love a group of animals that's so strange they change science. Yeah. That's awesome. That's like when you – it's like stories of finding another planet. And astronomers go, oh, okay, so we were a little bit wrong about the solar system. Yes. Like, this thing here means that my equations were wrong, so we have to, like, recalibrate. We found a thing. Caligotheos are like that, where it's like, oh, okay, we're wrong about some stuff because this exists. This means that we must be wrong about some things. Well, and they were found at, like, such an interesting time because there was also a note from Cuvier with the first discoveries that said, like, this is such a this is such obvious proof that there were creatures on our planet unlike any today and that some cataclysm caused them to disappear like they were also reinforcing ideas of extinct groups and extinction events because they were so obviously not anything analogous to what we have today yeah and especially if you were finding them in europe where it's like because again, it was very easy, especially at that time, for European and American scientists to go, well, in Africa somewhere, or in South America somewhere, in the depths of the Amazon, or in the Congo, or places that hadn't been thoroughly explored or understood by Western scientists, it was easy to point over there and go, ah, who knows what could be in there. But if you were finding these fossils in Europe, that's like, well, we have a pretty good handle on Europe at this point in time. Whatever this is, it does not live here right now. Yeah, precisely. So they stood out quite clearly. Cool. Well, next, we can discuss where Calicotheers came from and how they came to be. But that will be after the break. How did this happen? Well, who did this? Who did this? Just like in Diddy Kong Racing. stay tuned so in the n64 game diddy kong racing there were a bunch of cheat codes that you could enter and there was one that you could enter to play the credits and the code was right yeah yeah So, Will, who did this? So, Calicotheres as a group get their origin pretty early on in the age of mammals, back in the Eocene. The earliest identifiable Calicotheres can date back to about 46 million years ago. Okay. These are from Asia and are going to be primitive members like Potomoropus. So this, as well as other lines of evidence, seems to support that they started in Asia. Interesting. So they're an Asian group. The early Calicotheres are often referred to a family called Eomeripidae. This group ranges from about 46 to 33 million years ago. They are very clearly Calicotheres, or at least closely related to the true Calicotheres. These are in Calicotheroidea. They have similar bodies. They do have claws on their feet, so they might be the immediate ancestors to the later true Calicotheres, as we think of them. They did tend to be much smaller, so like sheep-sized, so not as big as later members. There is at least one member that I found notes on, Litholophus, which is considered to be one of the more basal members of the group, earliest and more primitive, so to speak. It's very similar to other basal members of parasidactyl groups, and its feet seem to end in hooves, not claws. Oh, interesting. So it does seem like the early, earliest members of click theories also had toes more similar to a taper or a rhino. Yeah, which makes sense. That's what you would expect to be the case. And in fact when you said that those earliest ones had claws my thought was oh wow so the claws evolved early early on Yeah yes And it does seem like they still were a barely early feature That the only one I found mentioned and most other things I found talking about it said we don know whether the earliest members So this is the only one I saw mention of, so it might be the only one we know, or that might be not as for sure about this creature. Right. It might be a close relative that had retained hooves, yeah. But maybe the very earliest members had hooves still, but the other early Klykitheers and Klykitheer ancestors seem to already be clawed. Past that origin, I did not find much else information, considering that we are still debating exactly who they're related to. We don't know which group they evolved from or evolved, you know, split off from. And we don't seem to have any specimens older than these origins. So it's likely that we just don't have that info yet. But Asia origin, by the late Oligocene, we see the splits, or at least by that time, the two subfamilies have split, the Calicatherinae and the Schizotherinae. These are linked together in the derived Calicatheres, or the family Calicatheridae. Sure. True Calicatheres. true Calicothears. It's not yet clear how or exactly what the Diamond Epic was with that splitting. So we still don't have a ton of information on exactly when they showed up. But the first Schizothyrenae appeared in the Oligocene in Asia and North America. And the first Calicothyrenae are known from the early Miocene in Asia and Africa. And the Miocene is when we see them reach their greatest diversity, but it seems like they were never common animals. Yeah, that is, yeah, Miocene is what I associate them with. That's when I think, yeah, around, you know, 10 to 20 million years ago, Calicotheres were a big deal at that time. But even then, not particularly common, and we still don't have a great fossil record of them. Exactly. So they seem like even during the time, you wouldn't have come across a Calicothera very easily if you were on safari, that they would have been a fairly rare member of the environment. Now, for their dispersal, they ranged quite wide. They started in Asia. We see the first members up here in North America in the Middle Eocene, but these would have been the basal, you know, Eomeropus and stuff. So not the true click appears yet. But we do see members of the overall group in North America almost as early as their origins. So they were spreading around. It just wasn't the iconic groups yet. Interesting. That is interesting because horses and rhinos start in North America, which would mean either they spread out, gave rise to Calicatherism, and some of them came back. Or we haven't found those earlier ones who did actually start in North America before they spread over to Asia. Yes, yes. They didn't reach Europe until the middle Oligocene abouts. Then we see the advanced Schizotherians moving into North America in the Oligocene-Miocene boundary and eventually spreading down into Central America. And then both subfamilies did make it to Africa, but not at the same time. the exact timing seems to be not quite clear. Anglotherium is an African and Eurasian member, and based off the evidence, it seems like they moved from Eurasia to Africa, and that had to be at least 10 million years ago in the Miocene that that happened. But exactly the timings don't seem to be as clear with Africa. So they were a widespread and at least relatively successful group. Yeah. And this was one thing noted in the like history and the people studying in the past that they we could not write them off as just some anomaly. You know, they weren't just weird because it's this one off weird thing that happened. They were being weird for millions and millions and millions of years all around the world. So surely this had to be a successful way to be an animal, which led to questions about what kind of animals were they? How did they live? How did they move? What were they? What were they doing? This is the moment I've all been waiting for. Yep. The first ideas very much stemming from the comparison to pangolins. But even after that, it was clear that they weren't pangolins. The idea that they were diggers held on for quite a while. Sure. Big claws. Big claws, their claws are superficially quite similar to pangolins, and features of it, they have a notable bony core with a deep cleft in them, which is a feature we also notice in Ant Eaters and the Bandicoot and Moles. They seemed like digging claws. So the idea that they were diggers held on early on, before they were identified as herbivores, it was thought that they were probably just eating like an ant eater, you know, digging into nests of insects and gobbling up grubs and ants and termites and stuff. Once we knew they were plant eaters, it was suggested that they were digging for roots and tubers and truffles and things like that. And even when we moved away from them being eating underground things, the digging idea still held on. So once we thought maybe they're browsing more, they're eating above ground plants, but maybe they're digging for water, you know, to find a watering hole or to supplement their diet with roots and stuff. The idea of them being diggers held on for quite a while until 1923 is the latest suggestion of digging behaviors that I found. But anatomical studies of the skeleton show that though the claws look like diggers, the arms do not. Sure. That makes sense. Yeah, you can't dig with just claws. Exactly. Give a baby a shovel, and it's not going to do much digging. Or if you put a shovel on a bendy handle. On a pool noodle. Exactly. You're not going to dig, even though you've got a great shovel head up there. So it did not seem like they have any digging adaptations in the skeleton. So it's unlikely that they did really any digging whatsoever. We can't rule out that none of them dug ever, but it's not likely. And like, I can dig, you know, like, you know, but I'm not specialized for digging. Yes. So as more research came around, more and more evidence supported that they are browsers, you know, so they are eating plants, you know, leaves and stuff, low-lying branches, that they are eating foliage, not grazing the grass, but eating the stuff in the trees and bushes. Based off of their anatomy, the idea of them being bipedal browsers came up, that they stand up to reach higher branches and maybe like prop themselves against the tree with their clawed forelimbs to reach up and get to things. We see bears do that. Exactly. Yep. Yep. And it's been suggested for ground sloths as well. Yep. This, you know, also thing of like antelopes that come up and stand up to get into trees, but them having these claws like those other groups to hold on and balance themselves. We do note things on their hips that seem to suggest some stresses from standing on behind limbs. They've got they've got butt calluses. Yep. From when they're sitting down. And that's the thing is between the two groups, we do have those very different body types. So they both seem to be browsers, but they were probably browsing in slightly different ways. Sure. The Klycotherians were likely browsing much like a gorilla or a panda. And they were sitters. Sit down, reach up, pull plants to you and eat it. And they have adaptations that seem like specializations for long-term sitting, things we see in other primates and apes. Amazing. The idea of a horse that has evolved to sit and pick up food with his hands. Yep. Wild. The schizotherines have those longer necks and seem to be more quadruple, but still had a lot of adaptations in the back legs and the hips that suggested they could raise up on the back legs, but not likely as for sitting, but standing up to reach food, going up the tree. So this is more like those antelopes that stand up on their hind legs. Maybe still pulling things with the arms a bit, but having a long neck and mobile lip and long tongue based off of the structure of the jaw and skull, it seems very likely they had some sort of structure there for reaching further up into the tree. Which would explain that. That's an interesting tradeoff to notice, that the group with the less prominent front arms seems to have longer necks and more flexible lips and tongue. Interesting. Yes. Yep, yep, yep. So likely browsers. This is supported by studies on the teeth. The micro wear on their teeth support a browsing diet. Their molars are not super robust, you know, like a horse's. They're, you know, a bit shorter and often seemed more unworn, which also led to the idea they're eating softer vegetation, not grass, which is very abrasive. studies on the teeth have revealed that yep all click of here seem to be browsers we don't have any that seem like they were eating anything surprising for the group more basil members seem like they were eating things similar to early horses and that they were like fruit eaters and eating very soft foods okay while the click of the renaid generally there's you know a few members in both sides that have some features, but generally speaking, our gorilla-shaped ones were eating tough foods. They tend to have shorter teeth and less exaggerated molars. The wear on their teeth, things like pits, the amount of pits, the size of the pits and teeth, and big scratches suggest they were eating things like fibrous fruits, seeds, pits of fruits, and nuts. Even though they had relatively short teeth, it seemed like they were eating fairly tough food. And then the schizotherines had more robust molars and seemed to be eating also tough but different tough food slightly. They had large pits, but as they said, the gouging is more prevalent than puncturing, suggesting that they were eating food like twigs and bark. Sure. So all seem to be browsers and specialized for fairly tough foods, not just soft leaves. Yeah, which is also true of gorillas. Yeah. They eat relatively tough materials. They also show interesting relation with that in the click of the urinate, they lose the upper incisors and retain the lower incisors. Like a deer. And that we see similar things in things like meropus, which they compared to having very ruminant-like dentition, that no upper incisors, prominent lower incisors for nipping off food, and a large diastema, a gap between the front and back teeth, which is part of the evidence that supports them having a long tongue, is the shape of those teeth and jaw. So we've got these browsing animals, browsing in different ways and eating different parts of trees and brush and seemingly living in different environments. Sure. That makes sense that they are specialized for different habitats. Absolutely. When we look at the two subgroups, we see both that their fossils are found in deposits that indicate different ecosystems and that they seem to be specialized for different environments. The Calicotherians mostly lived in moist, canopied forests. Yep. Same places we find gorillas. Yep. Very expected. I was going to say, it's got to be that the Schizotherians are living in open habitats. Yep. And the Calicotherians are living in more dense forests. That has to be what it is, right? Absolutely it is. Absolutely it is. The environments they're found in support that. schizotherians live in a it's still forest and woodland but also savannah so more open less jungly yes by the way listeners the reason that i say that is because the schizotherians are more horse-shaped they're more walking adapted they've got those long legs the long neck whereas being able to sit down and reach up and grab stuff with your hands is a forest thing that's just a forest thing to do. That's a thing you do when there's lots of food around and you can sit within arm's reach. Yes, exactly. And they compared also that like Moropus and many Schizotherians have an anatomy very similar in proportion to an Okapi. With slightly longer front legs, long neck, forest dwelling. Okapi is the cousins of giraffes, the forest giraffes. Episode 159. If they also had that longer tongue, it may have been that they lived very similar to Okapi's, but with the ability to hop up on the back legs a little bit. I'm so glad you brought up Okapi's, because this whole discussion I've been trying to come up with a comparison for the Schizotherians, and it's Okapi's, absolutely, with the long tongue, and they're kind of sloped in the shape of the body, which giraffes also are. And I even thought about saying that Schizotherians are on the road to giraffe-shaped. Yeah. They've even got head ornamentation. They've got bulbous heads. And I, like so many, forgot that okapis exist. Right? And this was noted even like even the earlier days, someone finally went, it's kind of like an okapi. And all the other scientists went, right, okapis exist. Yep. Yep. So, yeah, it's likely that we had the gorilla calicotheers and the okapi calicotheers. living in similar environments to those two animals. Fascinating. This also is notable in the fact that not only do they seem to be living in different environments, they are very rarely found in the same fossil site together. Interesting. I was wondering. I was wondering that. It was thought by some that they could not coexist because of how different they were environmentalized or that they would compete because they're both browsers, you know, clawed browsers, and that they might be eating too similarly. But we do have a few very rare instances of them being found in the same fossil deposit. So it does seem possible that they maybe have overlapped and coexisted, and that maybe there could have been lack of competition because they were different kinds of browsers. Yeah, or maybe there were certain, like, border habitats, where, like, mostly this group is living to the east and this group is living to the west, but there's this in-between area where they both can find food. But generally speaking, if you find one, you don't find the other group in that same place. Interesting. It also seems like just based on the rarity of their fossil finds, it seems intuitive to me that they were either not very abundant animals, that there just weren't that many of them. I'm thinking like tapers, to use some of their close relatives. Tapers are just not that common in terms of animals, and they're also not gregarious. tapers rhinos this is also true of where generally speaking you're gonna find if you find one you're gonna find one at a time and it's interesting that calicotheres have such a sparse fossil record given that the fossil record of rhinos and tapers is actually pretty good but that being said the examples that come to mind off the top of my head are examples at certain fossil sites where you get an abundance of them. Yes. Where maybe they were being more social, more gregarious in their lifestyles. Yeah. And I did find it noted that even in fossil sites where we find members of similar sized mammals, that we find very few chlycotheres, suggesting that they were very rare in their environments and that they were not living in groups or herds, which would make them fairly unique out of the group as it seems they, at least of the species we have so far, never evolved herd behavior. And we do have examples of other members, you know, in every group just about that had grouping of some sort at times, but it seems this group didn't do that. Interesting. What an interesting and strange group of animals. They're so delightfully bizarre. I love them. And then finally at the end, their extinction, I don't have much info on. They went extinct in the early Pleistocene, right around the same time as other big bodied mammals during the megafaunal extinctions. I didn't find any specific insights on, particularly, it seems like it's probably the same reasons that many other species were going extinct. Sure. Well, and if they're disappearing in the early Pleistocene, they're ahead of the curve a bit. They're actually disappearing before the bulk of our megafaunal extinctions at the end of the Pleistocene. We do see that chlycotheres in general start to decline in the late Neogene. So in North America and Europe, they start disappearing by the end of the Miocene. And then the latest North American chlycotheres is Meropus, which is extinct by 13 million years ago. And then the youngest clikatherines we have are some clikatherines in the early Pleistocene of China and Myanmar, and at least one schizotherene and chylotherium from early Pleistocene in southern Africa, and maybe early Pleistocene of China. Yeah, so they were, it sounds like, potentially gone by, you know, halfway through the Ice Age. Yeah, so they were some of the early members going out. Like I said, I did not find any mention as to, like, why we think they went out before other groups or why they were declining before the bulk of the megafaunal extinctions, just that they seem to be to kind of peter out starting around the end of the Miocene and continuing from there. Well, and a quick double checking of my categories here. the late Pleistocene officially starts pretty late into the Pleistocene. So they were perhaps closer to those other megafaunal extinctions than it initially sounded. Yeah, from the dates I was looking at, it looked like they still fell within the brackets for it. Well, and it also is a group that is famously not abundant. Yes. So it's really hard to know. you know it wouldn't be particularly surprising to find caligather fossils that are later than we currently have that yes you know in a few years we'll find one that oh they actually did make it a little bit later in this or that place yeah well with a grant with a group like this it's very difficult to know because when you have such a spares fossil record there's not enough to find good trends. Yes. Right. When you have an abundant fossil record, when you're like a lot of the other ice age, megafauna or things like megalodon, where this comes up, where like this has an extremely abundant fossil record and then it ends. Yes, exactly. Calicotheers are tough because they have a sparse fossil record and then it stops. Just like it peters off and that makes it hard to know for sure the details. Yeah, and so it's, yeah, there's could have been island members hanging around somewhere or doing something, but even though they were widespread and around for a very long time, they were never dominant members of their ecosystem. They were never, you know, grouping in large herds. So it's, yeah, I think the idea, like, kind of like how bears are today, where they range quite widely and not probably, maybe not as rare. I don't know how the comparison would be, but you're not going to find a herd of bears. And you could be in an area for quite some time and never see a bear, even though they do live there, because there's only a handful of bears on this mountain. Yes. And so that is a kind of group that can actually disappear surprisingly quickly when things change, if it's no longer fitting for, especially because these were big animals. What a fascinating and mysterious group of mammals. I love, I always thought they were cool. I love them so much more now that I've learned all about them. Yeah, that's very neat. Yes. Hope you all enjoyed our analysis of Calicotheres. If we didn't mention, like, a favorite member or, like, a favorite example or something, let us know. If there's other things you think are cool about this group, chime in. You can go onto the Discord and let us know your thoughts about this weird group. Before we wrap up the episode, we have one last thing, which is our patron question. Every episode, we like to answer one of the questions submitted to us by one of our patrons, which you can do if you sign up at certain levels. What's our question for today? This episode's patron question comes from Dr. Foramtastic, who asks, Do you have a favorite example of convergent evolution? Something weird or improbable or just really cool? As a reminder for our listeners, convergent evolution episode 70 is the phenomenon where two distantly related or at least not very closely related groups of life evolve surprisingly similar features, typically for very similar functions. I know Will has favorite examples of convergent evolution. Absolutely, I do. And I felt like this was a this is a very fitting question for this episode because callicotheres are so clearly convergent with other animals. We mentioned gorillas and okapi and that they have this body shape that is for a very similar lifestyle, but wildly different group. Of course, crocodilians and the croc shape is my favorite top example. This is not a particularly weird or unusual one. That one is kind of one of the standards. I think my favorite weird one is IIs and woodpeckers. Oh, yeah. That is one of my favorite examples of convergent evolution. Woodpeckers, famously, peck into the bark of trees to get at grubs underneath, and they have a long barbed tongue that they fish into the hole to get out the larva. I.I. are primates, lemurs, that have chisel-like teeth, and they have this long, skinny, dexterous finger that they tap on the wood to listen for the grub in the hollow spaces, and then they bite a hole into the bark, and then they fish it out with that long finger. So all the same steps as a woodpecker, but with different devices, and a completely, you know, one's a bird and one's a primate. Yeah. One of my favorite phrases that I have said many times on the podcast is the way that I like to describe mosasaurs, which are lizards that are convergent with whales, which is just phenomenal. And I love it so much. Another example that comes to mind, and I don't actually remember the details of this, which is to say it could be wrong. But I'm pretty sure that there are so humans, people who live in places like Tibet have been noted to have certain adaptations in their body systems that seem to be better for high altitude lives. And I think these are like genetic differences that have been noticed that affect the way like the blood absorbs or utilizes oxygen, stuff like that. There are some of these high altitude adaptations in humans. And I believe extremely similar adaptations have been noticed in dogs in those same areas that the humans and their dogs are both having the same adaptations, which is very cool. I do love when we find stuff like that where it's like we're trying to figure out whether this group lived this way. And then we realize, oh, your ear bones are the same as this other group that lives this way. And like you don't look like that group in other ways, but your ears do, which suggests you were swimming the same way. Or what I love those little ones that you go, well, what adaptations does that group have to survive there? oh, their blood vessels are weird or their, you know, gut is unique. And then you find out, oh, yeah, the other one's doing the same thing. I love it. Yes. But probably my top favorite example of convergent evolution, which is, feels like there's a reason I've made sure to say a couple others first, because this feels like such a boring answer. I think, I am on record having said, I think the most ridiculous thing that evolution ever did was evolve flight. And the fact that it evolved four times in four separate unrelated groups of animals is preposterous. That's magic. That is absolutely ridiculous. It's one of those where if we didn't have flying animals today, I think we would be utterly incredulous at the idea of an animal flying. Absolutely. That if it wasn't so common that if someone from another planet came and went, oh, you don't have any birds, we'd be like, of course not. Gravity exists. You don't. That doesn't make any sense. You're probably wrong. Yeah. Yeah. The fact that it's common is insane. Yes. Very cool. Thank you for that question, Dr. Foramtastic. And thank you for your support on Patreon. done. Absolutely. If any of you out there have a favorite example of convergent evolution, absolutely share it with us. Go into the Discord or make a comment about your favorite example of convergent evolution. I would love to see everybody's. With that, we can wrap up this episode about one of the coolest and weirdest groups of mammals that ever existed. If you want to learn more about Calicotheers and their awesome features, and if you actually want to see some pictures of them, check out the blog post. There'll be links and images there. Don't forget, if you missed our anniversary livestream, you can find it on YouTube and see the announcements we've made coming up for this year. Also, coming up shortly is the first episodes of Poke-E. Woo-hoo! Poke-E all through February and beyond. So check in for that. It was a ton of fun coming up with realistic Pokemon. Thank you to everyone who requested this topic. Thanks again to our new patrons. Welcome. And top thanks to our tippy-top patrons, Sarah May, Jeff Ellington, and Danielle Loves Bugs. Thank you to all of our supporters and all of our listeners and everybody. Yeah. Welcome to, it's a whole new year. 2026, all sorts of cool stuff's happening. It's good stuff. Stay tuned for another year of all this nonsense. next episode Darwin Day yeah and that will be in a fortnight because we're not changing that this year that's gonna we've re-upped for that subscription for another year so you can expect that to be standard and with that I don't have anything else to say I don't have anything else to say make a pun about callicatheers and then play the music this is one of those where I could have listed basically every species that I think we know, but I didn't have anything notable to say about a bunch of them, because it's like, and then there's this species, which is a name. Which is a pile of crumbs. Yep, yep. At least each genera, like each genus of Klykithere, there's like a dozen-ish. So this is one of those rare instances where this is definitely not all the info about this group, but this is probably a good chunk of it. A decent amount of what's out there. Bye, everybody. Bye. which we found at ocremix.org. Thanks again for listening. We hope you'll join us next time.