Sauropod Shindig

This episode is brought to you by the Colorado Northwestern Community College. Join them for two weeks digging up fossils like dinosaur bones in northwest Colorado this summer. For details, go to cncc.edu slash paleo26. It's that time of year where you can get an exclusive patch from us, but only if you're a dino-it-all in our Patreon community. For the first time ever, we're doing a sauropod this year, Bajotosaurus, and it turned out great. If you want to see it, head over to patreon.com slash I Know Dino, and if you want to get it, make sure you join at our Triceratops tier or above by February 28th. Hello and welcome to I Know Dino. Keep up with the latest dinosaur discoveries and science with us. I'm Garrett. And I'm Sabrina. And today in our 559th episode, It's a sauropod shindig. We're doing shindig again? Well, this was a request from Weiser. Sauropod shindig, and then Morgan, these are our dino-it-alls, said it was very fitting since sauropods are often discovered from long bones, so to find them you have to dig up shins. A shin dig, I get it. Yeah. So we're talking all about the group sauropods, Plus, there's five new sauropods. There's new sauropod nesting sites and embryos, sauropod speeds, and sauropodomorph tail weapons, and more. I guess a shindig sounds better than a tibia dig. Yeah. Rolls off the tongue better. Yeah. We also have dinosaur of the day, Cediosauruscus, a sauropod with a long history. Not to be confused with Cediosaurus. That's what I was going to say. Don't worry, they're intertwined. Kind of. And our fun fact is that some sauropods could rear up for long periods of time. Whoa. Mm-hmm. I'm excited to see how we know that for sure. I'm excited for this whole episode. But before we get into this episode, we need to thank some of our patrons. You already mentioned a few who suggested this episode, but I need to correct a patron shout-out from last week. I thank Sophia, but I missed the dinosaurifying part of their name, which is Sophia Antuosaurus. So thank you very much for joining. And then we have a new patron to thank this week, and that's Leon. And then rounding out our shout outs, we've got Samisaurus and Canonicus, Irapdosaurus, Jessica, Beagle, Jesse, Ray, Will, Collie, and Michael. Thank you so much for being a Dino-It-All and being part of our community. And look out for our Bajadasaurus patch next month. Yeah, not too late to join. Yes, it's not. If you want to get yours, make sure you're at the Triceratops tier or above at patreon.com slash I Know Dino. All right, time for our sauropod shindig. So I'm going to start with sauropodomorpha. They're the lizard-footed forms that include sauropods and their ancestors. But the only thing they have in common with lizards is they both have five toes. Yes. The soros. The sauropods were the largest land animals to ever live. They're one of the most successful dinosaur groups. And they lived a long time. The earliest members of sauropoda evolved in the late Triassic, and then they lived until the late Cretaceous. They were there the whole time. Yeah, again, late Triassic is when dinosaurs came around, even though it was in the middle or before the middle of the Triassic, just because Triassic time periods are named in a non-intuitive and confusing way. The late Triassic is almost all of the Triassic. The early sauropodomorphs walked on two legs, and they were omnivores or even carnivores. They might have been basically the earliest dinosaurs, depending on what you think of thylosaurs. Oh, yes. So for example, Pladeosaurus is a sauropodomorph. It was large for its time in the late Triassic. It walked on two legs. It could walk on all fours, but it had a relatively long neck and tail, and it had big thumb claws. The sauropodomorphs had a system of air sacs in their vertebrae. They had hollow bones, which helped reduce the weight of their long necks and allowed for single-direction airflow, so it was possible to get enough oxygen. This is similar to birds, which use their air sacs to keep cool and helps them stay light. And that's why sauropods and theropods are often lumped together into psorischia. Because they have that common trait of the air sacs. I just wanted to bring up that sauropod are the lizard-hipped dinosaurs, but sauropod means lizard foot. Yep. Yeah. Psorischia is lizard hip. Yes. And this group was named by O.C. Marsh in 1878. So as for those lizard hips, that means that their pubis pointed forwards, like in lizards, and like you were saying, Garrett, that makes them part of the group psorischia with the theropods. Sauropods are known for their long necks and tails and the small heads and the large columnar limbs, usually, and for being so large, usually, because they are the largest herbivores of all time. Oh yeah, that's true, because whales are carnivores. So that makes them the largest herbivores, period, including things in the ocean. Yes. What an amazing title. The earliest known sauropods are from the early Jurassic, and they were herbivores with long necks. They walked on four legs, and they had tiny heads and large bodies. There are about 300 sauropod species, which is why we get to keep talking about them over and over on this show. Yeah, that's a lot. I will say, they do have very small heads compared to their body, but if you hold a sauropod skull in front of you, it's about as big as the chest or the torso of an adult human. Which you might expect since they were so large. Yeah. Sometimes I'm a little bit surprised how big their skulls are when you see it up close, though, because I'm used to seeing it in proportion to the rest of their body, and it's like, oh, that's actually still a decent-sized head. They could still eat all the stuff that we would expect them to encounter. Yeah, kind of like how T-Rex arms were only small compared to the rest of its body. Yeah, it's kind of like a human leg sort of situation, yep. So there's a number of groups within sauropoda. We're not going to get into all of them, but we will get into some of them. One group is the neosauropoda, which basically means new sauropods. Garrett's talked about this before we did a whole segment on sauropod classification. They're not really that new. They evolved in the early or middle Jurassic over 170 million years ago. And then within Neosauropoda, there's two main subsets, Diplodicoids and Macromerians, which brings me to our first new paper, Introduction to Diplodicoidia. Oh, that would have been a handy one to have when we were doing that episode. Yes, it was handy for this one. This was published by Tom T.P. Vanderlinden and others, which includes a lot of sauropod experts. and it was published in Paleontologia Electronica. It's open access. If you want a very thorough introduction to Diplodicoidea. Yeah. We've actually talked about this paper before and how they were crowdfunding to publish it and add art. It's an intro to a special volume that synthesizes the research on Diplodicoidea. That's right. So apparently the crowdfunding went well. Well, I think they were already published. They were looking for the art. Oh, gotcha. So Diplodicoidea is a superfamily of sauropods. The other superfamily is Macronaria, which includes titanosaurs. Diplodicoidea, they're known for their distinctive skulls, the long skulls with the pencil-like teeth, and having very long necks and tails. Often much longer tails than necks. Yes. They're more horizontal compared to Macronarian sauropods, too. Yep. I usually think of Diplodocus when I'm thinking of Diplodicoids, and I think of Brachiosaurus when I'm thinking of Macronarians. Yes. That's sort of my shortcut in my head, at least. Diplodicoids lived in the middle Jurassic to early, late Cretaceous. They include the families Ribachysauridae, Dicrarosauridae, and Diplodicidae, or Diplodosidae. I've heard it pronounced a couple ways. Depends on which side of the pond you're on. Yeah. So they lived around the world, and they had diverse body plans as well as different feeding strategies, and they fill different ecological niches. The name Diplodicoidea comes from Diplodocus, so it's fitting to think of Diplodocus here. And that name means double beam, Diplodocus. And they're called that because they had small bones that attach under the tailbones, the chevrons, that were split down the middle. So there's two quote-unquote beams. They had long skulls. The snout is squared. They had nasal passages at the top of the head. Some of their snouts are more squared than others, like those Robachysaurids. Oh, yes. I forgot to mention, I'm now talking about Diplodacidae within Diplodacoidea as a mouthful. So the ones that are more closely related to Diplodocus than some of the other Diplodacoids. Yes. They had nasal passages at the top of the head above the eyes, but the nostrils were more in the front of the snout so they could sniff what they were eating. It's convenient. Usually. Unless it smells bad. Yeah. But they're eating it. Oh, that's true. They had pencil-shaped teeth. They're sometimes described as crayon-shaped and blunt at the end because they used them a lot. And they probably raked the teeth along branches and pulled off needles and leaves. The front legs were shorter than the hind legs, which means that their center of mass was around the hips, and they could rock back onto their back legs. So it's possible they stood on two legs to get higher up in the trees and maybe even used their tail to get in a tripod-like pose. They had flexible necks, at least they could use them to look down, and that makes sense if you're up on two legs and you bend your neck down in front of a tree and move it up and down to get to the leaves. And they had long, whip-like tails. For a while, the tails were thought to be used for defense, or at least that they could make a whip-like cracking sound over 200 decibels, similar to the volume of a cannon. A number of diplodokids have been found with fused or damaged tailbones, and that could be from cracking their tails. But a 2022 study found that this was unlikely because it would have been just too damaging to the large, heavy tail. And in fact, the tail would break. We talked about this in a previous episode, episode 423. I still think, though, you could potentially have some sort of, like, feather filament-y type situation sticking off the tail end of it, the tip of the tail. And then you could make a little noise or maybe do a little something without damaging the rest of the tail. Yeah. Well, so it's possible that the tails were used to communicate and keep in touch with other members of the herd. And it is also still possible that they helped with defense because they found that the tails still could move pretty fast and they were stiffer than previously thought. Just not in a cracking a whip sort of way. Yeah. Most likely. So then we've got Rabaki swords and Dicreia swords. We're lumping them together. They're not as important as the diplodocids. They get combined. At least in this episode, yes. I mean, they're still important. Anyway, Ribachysaurids were basal diplodocoid sauropods. They appeared in the early Cretaceous and lived until the early late Cretaceous. And they're known for having a highly pneumatized skeleton. They're just full of air sacs and very light. They've been found in South America, Africa, North America, Europe, and possibly Asia. and they're known for their teeth. Some of them even had tooth batteries. I'm surprised that they didn't mention the whole super flat front of the mouth being the thing that they're known for rather than like pneumatized skull. Because to me, the thing is like they look like vacuum cleaners. They've got that really flat front of the mouth like Nigerisaurus. Right. A lot of them. Maybe it's not all Robachisaurus. Yeah, maybe not all of them. It's kind of like how with Ceratopsians you often think of the frills and the horns but that's not what makes them a Ceratopsian. It's the beak. I guess so, yeah. But a lot of Robachisaurus have that, at the very least. And then Dicreosaurids, they're known for having shorter necks. It's kind of what sets them apart. They do have really short necks, but they also, in some cases, have those crazy spines sticking out, like Amargosaurus and Bahatosaurus. That's what I think of with Dicreosaurids, but I know they didn't all have that. Yeah, that's usually what I think of, too, but they don't all have it. And in general, they're just kind of small. So next that brings us to the Macronerians, which, Garrett, I'm going to let you talk about that because you talked about that in our episode 495, Why Dinosaurs, when we had a whole segment on sauropod classification. Yeah, they are the other neosauropods, the other new sauropods, meaning from the early Jurassic onward. So they include Chimarasaurus, Brachiosaurus, and all Titanosaurs. So it is a pretty broad group. Basically, all the things that aren't in the three groups you mentioned, the Dicreosaurus, the Rockpachysaurids, or the Diplodokids. Macronarians have small individuals, but also incredibly large individuals like Patagotitan. Most Macronarians have shorter hind limbs than front limbs, which tend to give them a more upright neck than Diplodokids. Like you were saying, they have a more upright stance, not as horizontal. So, yeah, Giraffa Titan, Brachiosaurus, Camarasaurus all stood much more upright. Even Patagotitan and the Titanosaurus tend to have like a bigger shoulder and more of an inclined pelvis. Sometimes they point it to because that sort of shows the angle of the vertebrae in the back. Most cartoon sauropods, I think, would be unspecified macronarians because like the emoji sauropod, you know, to fit it into that shape. so it's not just like a long, straight line. Right. They have a sort of like curved up look to them. That neck posture probably meant that macronarians ate from taller plants, also known as being high browsers. And maybe that meant that they could live in the same environments as diplodicoids because diplodicoids might have been eating at or near the ground level, whereas macronarians could have been near the top of the trees. Well, the diplodicoids are going up on their tail. That's true. I mean, that's not the low energy state, though, most likely. But I especially think of those Robocis sores that look like they're really optimized for, you know, nibbling off near the ground. And we have found wear on some of the teeth of diplodocoids. I'm not sure about a macronerians. They have a fair amount of stones, so it looks like they're really getting some grit from the dirt into their mouth. Macronerians didn't replace their teeth as quickly as diplodocoids, but their teeth were generally larger and stronger. Again, that could be also a benefit if you're browsing higher, because if you're eating lower, you might get more junk, stones, and hard things into your mouth. Whereas if you're up eating at the tops of trees, you're less likely to get that kind of stuff in your mouth. But it might have also meant that they needed stronger bites to get through, you know, like some branches or something. So it can go either way. With Chimerosaurus, for example, they replace their teeth about once every two months, still really frequently compared to mammals, whereas macronarion teeth are often described as spatulate, spoon-like, or even chisel-shaped. Not pencil-shaped. Yeah, not pencil-shaped. It's one of the quickest ways to tell the difference between a macronarion and a diplodocoid. If you can't tell by the shape of the head and the arrangement of the teeth, if you look at the size of the teeth, it's got big old teeth. It's probably a macronarian. Many of the later macronarians, basically meaning titanosaurs, had a quote-unquote wide-gagged posture or a quote-unquote wide-legged stance. Basically, their chest was wider, which put their legs farther apart. Although, later on, people have pointed out that sauropods could adjust their stance more than we initially knew. So just by looking at footprints, you might not necessarily know if something was a macronarian versus a diplodicoid. But you would know it was a sauropod. Yeah, because like you were talking about the last episode, if you're driving your car and you're going through potholes, you might notice something's up and that's probably a sauropod track, if it's an anything track. Sultosaurus is also a macronarian. The sauropod, famous for its osteoderms, sometimes depicted with a tail club, but that is pretty speculative. I think I've been overly optimistic about its tail club possibilities in the past. I hope it did have a nice tail club, but we cannot be certain about that. But for now, we can hope. Yes. So that brings me to titanosaurs. I know you mentioned they are macronarians, Garrett, but we talk about titanosaurs so often it seems like we should call them out. Now, titanosaurs are very large. Yeah, most of them. That's true. Some of the smaller sauropods are found. And they lived at the end of the Mesozoic. The Cretaceous? Yes. Some species are the largest land-living animals discovered, but in many cases, scientists have found incomplete fossils. Yeah, there's a lot of that. We found a femur, and it's 2.1 meters long, so it must have been 80 tons. I was just skipping a few steps in terms of body mass and size estimates. And the name Titanosaur came from the titans of ancient Greek mythology. The family Titanosauridae was named after Titanosaurus, which, speaking of incomplete fossils, that's one. It's a partial femur and two incomplete tailbones. It was found by Richard Lidecker in 1877. Some scientists think there's just not enough information for Titanosaurus to be a genus, but Titanosaur fossils have been found on all continents, including Antarctica. Most Titanosaurus lived in the southern continents, which was then part of the supercontinent Gondwana. Now, compared to other sauropods, titanosaurs had small heads, and that's saying something. Their heads were also wide, though. They had large nostrils and crests formed by nasal bones. They also had broad pelvises and abdomens, which made them heavier, even heavier than other massive sauropods. Yeah. When you look at a diplodicoid, or maybe a diplodocid, I should say, next to a titanosaur, the size of their bodies really stands out. The diplodocid looks like a little tiny body with a long neck and a long tail, both pretty skinny, like sort of slapped on either end. Whereas a titanosaur looks like a big old chunky animal. And you can tell it by the weight estimates, too. A similar length titanosaur might weigh twice or three times as much as a similar length diplodocid. Yeah, because those tails of the diplodocids make a big difference. Yeah. So that's it for the neosauropods. but there is an important group that's outside of Neosauropoda that we refer to pretty frequently, and that is the Mementosaurids. They did not coexist much, if at all, with Titanosaurs because they showed up in the early Jurassic and they went extinct in the early Cretaceous, so they're really more of a Jurassic group. But Mementosaurids are most famous for their extremely long necks. I often characterize them as the opposite of Diplodocus or Diplodokids because Diplodokids are famous for those really long tails, less so for the long neck. Mementosaurs have a really long neck and less so on the tail end. Yeah, we've talked about before with Mementosaurs, some of the longest necks are estimated to be almost 50 feet long. What's that, almost 15 meters? Yeah, it's like the length of a school bus just neck, which is really crazy. and just all of the aspects of it, breathing through a 50-foot neck, eating through a 50-foot neck, drinking through a 50-foot neck. Moving a 50-foot neck. Yeah, pumping blood through a 50-foot neck. In a tail, you can kind of, it's like, okay, it's like having a really long limb and you can have certain valves in the veins and arteries and things to make it work. But so much goes through the head and neck that it seems much more impressive to see a mementosaur than a diplodocid in a lot of ways. So if you're wondering how we chose which sauropod groups to talk about, well, we've got five new sauropods and they all fall within these groups. Oh, yeah. We've got titanosaurs, dicreosaurids, eusauropods, and even a new species of mementosaurus. Nice. Yeah, I don't think I mentioned it, but mementosaurs are within eusauropoda, so that's a slightly broader group than neosauropoda. A quick note while we're talking about sauropod classification. Our patron, Mary, asked that they wanted to know what distinguished sauroids, sauids, and saurenes, which is a fair question. Yes. So sauroids are the broadest group, and saurenes are the most narrow. Usually. Usually. They're just different words, really. But that is usually how the words are used. So, for example, with the sauropods, you can take the superfamily Diplodicoidea, and then within that is the family of Diplodokids. So we got oids, ids, and then within that is the subfamily Apotosaurines. There's your eens. Mm-hmm. You also get it with Tyrannosaurs. There's Tyrannosauroids as the broadest. There's Tyrannosaurids. It's a little more specific. You just brought this up, was it last episode, with Ankylosaurs. Yeah, ankylos, well, that's ankylosauria. Although you can say ankylosauroids. Usually the oids is the broadest, but there are exceptions. So, yeah. But that's usually how it goes, because oid means that it's similar to, that's like the Latin part of it. And then the id ending, or ide, is usually used for a family level when you're talking about dinosaurs. And then the innae part is a little less consistent, but that sometimes is a subfamily. So hopefully that helped. I usually think, like, when we use the word oid, we usually use it because it's the broadest one. Id is generally for a family level, and then the in or en or in a, we don't use that much. Yeah. Unless we're quoting a paper that's really focused on that because it's getting a little bit too confusing usually at that point. Yes. I'm glad that that explanation works for sauropods, though. Yeah. So I just want to go back real quick on what sauropods looked like, at least a little bit. So we were talking about they had small heads, but they also had big guts to help them digest food. They could eat plants that were higher than everyone else, which gave them a huge advantage. And they had pads on their feet based on footprints. But the hands, quote unquote, or the forelimbs didn't have the padding. Some sauropods had armor. We can use Seltasaurus. Some may have had club tails, like Shunosaurus we were just talking about. Yeah, there's a lot of could have had. And also Saltosaurus, the osteoderm might have just been for nutrient storage, not necessarily armor. True. Asaurpods came in a range of sizes. We had some dwarf ones like Magyarosaurus, which weighed less than a ton and was about 10 feet or 3 meters long. That's cutie. Yeah, but then some are estimated to have been up to 190 feet or 58 meters long. I'll talk about the biggest ones in a bit, but that giant's thighs would have protected them from predators. For a while, it was thought that sauropods spent all their time in water because they were just too big and heavy to be on land. But Bob Bacher in the 1960s and the dinosaur renaissance showed otherwise, that they had compact, narrow feet for their bodies, not splayed out like aquatic animals. They also had narrow rib cages, and they were built more like elephants and giraffes than hippos. The earliest known artistic life reconstruction of a sauropod is by Charles Knight in 1897 with the help of Edward Cope, and it's of several amphicilius underwater when sauropods were thought to be too heavy to be on land. And then later that year, Knight illustrated the brontosaurus in the swamp, which might be one of his most famous ones. Is that the one I'm thinking of where it's sort of like a blue-green and it's got its head up and a mouth full of, like, seaweed? Yes. Okay. It's a good picture, even though it doesn't make a ton of sense with our current understanding of sauropods. Oh, but it is one of my favorites. Yeah. The intro to Diplodicordia paper mentioned the dinosaur renaissance in the 1960s and 70s. It's because of John Ostrom and the rafter Deinonychus. But Bob Barker also had a 1968 article called The Superiority of Dinosaurs, which included a pencil drawing of two Barosaurus, quote, striding briskly across a dry Mesozoic landscape with their heads held high. It's a nice description. Makes them sound like hoity-toity. Yeah. Although that reminds me of how his book, The Dinosaur Heresies, every illustration apparently has the dinosaurs kind of jumping or dancing. Yeah, they're all moving very actively. Yeah. Anyway, back to Berosaurus. In 1991, the American Museum of Natural History in New York unveiled Berosaurus in this rearing posture, defending a juvenile from an attacking Allosaurus. And there was some controversy around it, but it's iconic. And they said, quote, was likely the inspiration for the briefly rearing Brachiosaurus in the 1993 film Jurassic Park. Yeah, some connections we didn't know about. Yeah, that is a good one. I didn't realize that rearing Brachiosaurus was unveiled so close to the Jurassic Park film. Yeah, just in time. Mm-hmm. Now, sauropods, they tended to stay in warmer, lower latitude areas, and not just for the food, because it seems that they would have just shed too much heat in the neck alone if they were in cooler climates. Oh, yeah. I forget whose rule that is, but the one where animals closer to the equator tend to have shorter limbs. You could imagine a neck would be even worse because, like we were talking about, all the blood pumping, especially to the brain and eyes and things like that, that's a lot of surface area for a warm part of the body. Oh, maybe this is backwards because they were in the warmer, lower latitude areas because they would have shed too much heat, so they had the long limbs. Yeah, that's how it goes. Oh, okay. Animals in cold climates, maybe I said it backwards, tend to have shorter limbs in animals, and warm climates tend to have longer limbs. Okay. Despite the fact that overall body mass goes up in colder climates, but that's more like they become more spherical shaped, kind of. It's more of a gigantotherby thing. As for the history of sauropods, the first sauropod fossil scientifically described was a tooth. Rutellum implicatum. That's a non-Linanian description. It was described in 1699 by Edward Lude. But dinosaurs were not recognized yet. The term dinosaur wasn't coined until many, many years later. That sauropod tooth is possibly a cetiosaurid, and it lived in what is now England. Now, the first sauropods described were cardiodon, which means heart tooth, by Richard Owen. That was in 1841, based on a tooth. And Cediosaurus, also Owen, but that one was based on fragments. And that one was the same year, right? Yes. And we're about to talk about our five new sauropods, but first we're going to thank a couple sponsors. This episode is brought to you by the Colorado Northwestern Community College. We got a little bit more information on what you might be digging up if you join them for their field paleontology program. And what might that be? It is a large mammal known as Ewentotherium. Ooh. Yeah, Ewentotherium is in a group of animals called Dinosaurata. Sounds kind of like Dinosaurata. Yeah, even though we're talking about a mammal. Yeah. So, it's the same dino as dinosaurs, meaning terrible, and then serata means horns. So, a lot of them basically look like really epic rhinos. With the terrible horns? Yeah, really cool horns on their heads. Not all of them had horns, and of course, the horns don't always preserve, so it's hard to know which ones did have how big of horns, sort of like with Pachyrhinosaurus, that debate. But Euentotheria and animals like them were part of the Bone Wars because they are from northwest Colorado and southwest Wyoming. Not only is there really cool Mesozoic rock in that area, like the Morrison Formation, which is the most common one we talk about, but there's also Paleozoic rock before the dinosaurs and quite a bit of Cenozoic rock after the dinosaurs. And in this case, this is pretty shortly after dinosaurs went extinct. There was a quick surge in these dinosauratins, which are really cool looking. They remind me of a ceratopsian, too, another Sarah named group. So if you join them this summer, there's a good chance you'll get to dig up this really cool animal. So if you want to dig up this animal or join their field geology program or their lab techniques program, you can head over to cncc.edu slash paleo26. and they also have some scholarships available, and that information should be on the website shortly. Yes, so no reason not to apply to join. Mm-hmm. Yeah, it's a really great program. So again, head over to cncc.edu slash paleo26. All right, now we can get into our five new sauropods that we've been kind of teasing and dancing around. I'm going to start with a new titanosaur Ute Titan Zeligai Mondewaye this was published by Gregory Paul in the Geology of the Intermountain West and it's open access and this dinosaur was named in 2025 we are doing a little bit of catch up here there were something like over 50 dinosaurs named in 2025 so we're getting there before I get into that Eutitan, I do have to talk about Alamosaurus first because Eutitan is named based on what was previously considered to be Alamosaurus fossils. And there is some controversy about that, but more on that later. So Alamosaurus was a Titanosaurus sauropod that walked on all fours. It had a long neck, a long tail, relatively long limbs, and its body was covered in armor. It was estimated to be about 85 feet or 26 meters long and weigh up to 33 to 39 tons, although it may have gotten even larger. And we talked about Alamosaurus as our dinosaur of the day in episode 51 titled Alamosaurus if you want to hear more Yes covered in armor again maybe not what you thinking of with like an ankylosaur type covered in armor. Right. But it might have had many osteoderms, several to many osteoderms. Yes. More armor than other dinosaurs. Yeah. And it may or may not have been actually armor, or it could have been more for display and nutrient storage. So alamosaurus is the main or generally considered to be the salsauropod type in what's now North America. for a few million years of the late Cretaceous. Sauropods are absent from the fossil record of North America for most of the late Cretaceous. There's a nearly 30 million year period known as the sauropod hiatus. It's so weird, and I don't like it. Yeah. Well, Alamosaurus may have emigrated from South America. There's other hypotheses that it came from Asia, or there were sauropods in North America. They just weren't preserved or didn't fossilize. Maybe we haven't found them yet. Yeah, it just seems so hard to believe because like you were saying, with the shindig pun, the sauropod fossil is usually pretty obvious in the ecosystem. And they're not the kind of thing where like they tend to be completely obliterated by other animals. But I don't know, I guess maybe they all became mountainous and didn't fossilize or something. All of a sudden they moved to the colder regions. Yeah, it's so weird though that they're gone. Because I always want to depict Ankylosaurus with the sauropods, since Ankylosaurus is my favorite and you like sauropods. But other than Alamosaurus, maybe kind of, there's nothing. But then in the Campanian, about 83 to 72 million years ago in the late Cretaceous, sauropods do appear in the southwest of North America, the Titanosaurs. The Mastrichtians, the last stage of the late Cretaceous from about 72 to 66 million years ago. So the return of sauropods was over a 5 million year span of time. Alamosaurus fossils are found from most of the Maastrichtian. Greg Paul says it's unlikely that they lasted that long as a species. Because usually we talk about a species lasting, I don't know, a few hundred thousand years, maybe up to 2 million years. Yeah. Yeah, having just one species for a 5 million year span of time for an entire group like sauropods is pretty unlikely. Yeah. But that doesn't mean that you can prove it from the fossil record. But it's also unlikely because there were often different types of sauropods in the same habitat. Now, the holotype of Alamosaurus is a left scapula, a shoulder bone. And when Alamosaurus was named in 1922, they also referred a mostly complete right ischium, or hip bone. A more complete specimen was found in 1937 that Gilmore posthumously described, USNM 15560. It's a complete tail with 30 articulated caudal vertebrae, tailbones, a complete right forelimb or arm, minus the fingers, and both ischia in the hips. That was found in Utah. There was a sacrum from the hips in the field, but by the time that was tracked down years later, it had eroded, unfortunately. More fossils have since been found and assigned to Alamosaurus, although no skull has been found. Yeah, it's kind of par for the course with sauropods when they're missing a skull. Although a huge bummer for something like Alamosaurus, where we don't have anything else from around that time in that place. It could have had a really interesting looking head. Yeah. Now, Greg Paul named U-Titan based on the Utah specimen, that USNM 15560, which is why I brought up that specimen number. And he said that the fossils from the southwest U.S. and northern Mexico are incomplete, hard to compare, and some are from different growth stages. He also said the fragmentary fossils from Alamosaurus san juanensis from the Ojo Alamo formation in New Mexico are very different from partial skeletons from the North Horn formation in Utah. So he named the New Mexican fossils as this new genera Utes titan. I will say, Greg Paul, I would classify as a splitter. Yeah. I think when we talked to him, he took umbrage with that. But man, he's the splittiest splitter. he said that there may have been even more than two sauropod taxa he said there were multiple titanosaurids in southwest north america and they may have formed a mini clade as they evolved semi-isolated from the rest of the titanosaurs around the world which would be interesting and yeah pretty likely i mean we we certainly see that kind of thing in other dinosaur groups so he assigned and referred some additional previously alamosaur specimens to eutitan from the North Horn formation in Utah and the Black Peaks and Javelina formations in Texas. The details in the shoulder and hips are what make it unique, the different angles and subtle details. It's also got a more robust femur or thigh bone. The genus name Ute Titan is, quote, after the original Ute peoples of central Utah upon whose ancient lands the fossil was found, and the genus name Ute Titan means Ute giant. the species name zella guy mondewa is in honor of greg paul's quote maternal grandmother zella guy mondewi 1901 to 2002 born and raised in huntington utah end quote greg paul actually used the name utitan for the first time in the third edition of his book the princeton field guide to dinosaurs which was released in 2024 but based on naming conventions it's not until you publish the scientific paper that it's official. Yeah, although sometimes books count. It's a little confusing. Yeah. Definitely better to put it peer-reviewed if you can. So U-Titan is estimated to be 16 to 17 tons for the holotype and 22 to 24 tons for a larger specimen. He didn't give a body length estimate because it's just too hard with the fragmentary remains. Now, Brian Curtis wrote a couple lengthy blog posts addressing Greg Paul's paper naming U-Titan. The first one is titled Alamosaurus versus Ute Titan. So here's that controversy you were talking about, Garrett. Yeah. And Brian Curtis said that he was, quote, a lumper by philosophy. So we've got a splitter and a lumper at odds here. He also said the name Ute Titan is likely to stick. There could be a petition to designate that New Mexican specimen, USNM 15560, as a neotype for Alamosaurus. but likely it wouldn't be approved because the holotype for Alamosaurus isn't lost. There's also the argument for differences in the bones, although Curtis said that they may be due to individual variation or from taphonomy, just how it got fossilized. Brian Curtis said that he'd briefly considered naming that specimen, the New Mexican one, a new genus back in 2017 when he wrote a paper on the history of the Alamosaurus finding, and he was excited to read Paul's paper to see what characters were used to define the new dinosaur, but he said he was disappointed with the details. It just wasn't quantitative enough. Some things were described as fairly prominent or strongly prominent or modest in size. Yeah, which is usually you talk about something is absent or present, or you describe the exact ratio of something or the exact size of something, but you wouldn't use more qualitative language like this when you're describing otaphomorphies. Yeah. Yeah. He also said there was a mention of a femur, although the original Alamosaurus bones were shoulder and hips. The holotype is the shoulder, the referred specimens part of the hips. And he said that there were some errors in the paper. Another issue is that there's debate about the dates of the formations where the fossils were found. So a paper at the end of 2025 found that the age of the Alamosaurus holotype, where it was found, was the same as the North Horn formation about 66 million years ago, which would make the Ute Titan fossils about the same age as Alamosaurus. Oh, yeah. And it goes against that argument that Alamosaurus was around for too long. Yeah, so rather than being around for 5 million years, it could have been around for, you know, just a blip. Yeah. Well. At least as far as we found. Some might say 5 million years is a blip. That's true. Anyway, Brian concludes that Greg Paul is likely right, is a new genus, but from the wrong characters, and having more quantitative data would be good. So, in other words, right for the wrong reasons. Yes. And Greg Paul responded to Brian's blog post, which Brian posted in his second post titled Alamosaurus vs. Ute Titan Round 2. And he agreed with some things and disagreed with others. There's disagreement on the figures. Greg Paul used drawings, and Brian Curtis argued that photos would have been better. And as a side note, it's unclear if Greg Paul saw the specimen USNM 15560 in person. So maybe there will be counter papers in the future about this, like the ones for Greg Paul's Tyrannosaurus species. Again, that splitter. Or maybe not. But for now, we have this new sauropod. Yes. And a little bit more to add to the controversy of this paper. Oh, boy. The Google Group, which is the former dinosaur mailing list. I guess it's still called dinosaur mailing list, even though now it's a Google Group rather than being a mailing list. I talked a little bit about this in a live stream that we did with our patrons a month ago, but basically people are taking some umbrage with how many new genera Greg Paul has been naming, and often, like you alluded to, without necessarily seeing the fossils in person and maybe being a little bit too brash with naming things as fast as possible and some criticism about just trying to win more or less with taxonomy and naming lots of things without being an expert on that particular fossil. But the counterpoint is obvious, which is if this was discovered a long time ago, and even back in 2017, someone considered naming it a new genus and then didn't, it's been almost a decade, so one could see why it got a name. But then again, it could be like Ryan Curtis says, where he's right for the wrong reasons. Like, yes, it deserves to be a new genus, but this paper really didn't classify it and describe it sufficiently. So, yeah. There could be future papers. Yes, there could be. And then the debate is just like, well, should the person who did the more thorough analysis be the one to name it rather than the person that just put the name out there? But I'm not going to get into that whole discussion because it was over 100 long replies on the dinosaur mail-in list. And you could spend hours talking about that. I would say it's also tangentially related to dinosaurs because we want to talk about the dinosaurs themselves. The dinosaurs themselves, yes. And like you said, most people agree that this should, in fact, be a new genus. And it's more of the inner workings of how it was named that people are not happy with, for the most part. So back to Alamosaurus. Back to the dinosaurs. Back to the dinosaurs. A new Alamosaurus fossil was found. It was found back in March of 2025 in Big Bend National Park in Texas in the U.S. by a group of geology students. And this fossil is one of the most complete in the area. They found a large vertebra, which tells you something about how much we know about Alamosaurus when a large vertebra is considered one of the most complete. That's very sad. The fossil is now being studied along with associated vertebrae found in the same area previously collected. So it will be interesting if this changes anything for Ute Titan. Yeah, and it'd be nice if they found more of it. Yeah, although we'll see. Sounds like it's hard to find Alamosaurus fossils. Yeah. We've got four additional new sauropods to talk about. So moving on, we've got a new Athenar bermini. This was published by John Whitlock and others in Paleontologia electronica. This one lived in the late Jurassic in what is now Utah in the U.S. It was found in the Morrison Formation, and the holotype includes a brain case and skull that was previously thought to belong to Diplodocus. Well, they got Diplodocus or Diplodicoid. Yeah, Diplodicoid, because it's a Dichraeosaurid. Yeah. Good thing we talked about this. Yeah. The Fossils were first found in 1913 and briefly described in 1978 as Diplodocus by Berman and McIntosh, and it's housed at the Carnegie Museum of Natural History. The genus name, quote, is in honor of Cleveland musician and notable Pittsburgh Steelers fan, Athenar, hopefully I pronounced that okay, whose music was the soundtrack to the majority of the work done on this specimen and for whom no better paleontological comparison exists than a broken skull. I like that they were listening to the music. They're like, yes, we will name the dinosaur. That's like, I'm pretty sure Lucy, the really famous hominid, is named after Lucy in the Sky with Diamonds, because that's what they were listening to at the time. Music can play a significant role. Yeah. The species name is in honor of David Berman, who, along with John McIntosh, quote, did so much of the fundamental modern work on diplodicoid skulls at Carnegie Museum of Natural History and was responsible for the initial description of the specimen. Now, the skull pieces are large, especially compared to a skeletally mature diplodocus, a diplodocus that has finished growing. This one's considered to be a subadult because of sutures in the brain case, fibrous joints that connect skull bones. It's got characters seen in both diplodocids and dicreosaurids, but it was considered to have more dicreosaurid characters, and that includes fenestra, holes in the skull, in the frontal parietal and postparietal bones, if you want to know specifics. Now, since 1970, a lot more sauropods have been found in the Morrison formation. But now we have even more sauropod types in the Morrison. Thanks to Athanar. Yeah. Some other dinosaurs that lived around the same time and place include the sauropods, Diplodocus, Apatosaurus, Barosaurus, Camarasaurus. And then you got other dinosaurs, you know, like Theropods, Allosaurus, Ceratosaurus, and Ornithischians like Stegosaurus and Cantosaurus. But who cares about those? Not in the sauropod shindig episode. Well, next we've got a new titanosaur sauropod, Yanin hausei. This titanosaur lived in the Lake Cretaceous in what is now Argentina in the Bajo de la Carpa Formation. The fossils were found in 2003, but they weren't excavated until 2014, and then they weren't described until now. And by now, I mean, hey, we're kind of on top of things. This paper came out in 2026. Well, we're way more on top of things than the people that dug it up in 2003 and didn't name it until 2026. Yes, I think there was some backstory there that I couldn't find the details for. Anyway, they found three specimens, one which is the holotype, one which is assigned to Yanine, but not the same species necessarily. It's a hip bone, an ileum, and it's got unique characters, but the researchers were just not confident enough to say that it was the same species. and then one specimen is still being prepared, so it's unclear if it is also the same species. The fossils found include neck and backbones and a tailbone, parts of the hips, and several ribs. That's pretty decent. That's all from the holotype? No, from the two specimens. Okay. Well, I guess mostly the holotype because one of the specimens is just a hip bone, and both of them had hip bones. So details in the backbones or the dorsal vertebrae are what make it unique. Now, as a titanosaur, it walked on all fours in a more upright position. It had a long neck and tail and a relatively small head. And it was small to medium in size. It's estimated to be around 10 to 12 meters or about 33 to 39 feet long and weigh at least eight tons. That is pretty small. Yeah. As for the name, in the paper, the authors wrote, quote, Yannin is known in the Teuelche culture as a spirit or entity related to winter, cold, and winter nature in general, alluding to the La Invernada, a Spanish word that refers to the site where the cattle spend the winter, end quote. And that's where the fossil was found. The species name is in honor of Dr. Bernardo Alberto Hause, Nobel laureate in medicine and member of the commission that promoted the creation of CONICET, which is the National Scientific Technical Research Council. That's a cool origin name for a dinosaur. Yeah. It makes it sound kind of like you, Tyrannus, like being in a really cold, or maybe like Antarctopelta, because there's this really cold vibe to it, naming it after the winter and a winter site. Yes. Even though? Even though, I don't think it was cold when it lived. Yeah. It was cold when it was found. Yeah. That's always the thing. Are you naming it after what it's like in that spot today, or what it was like way back in a long time ago? Or what song you were listening to when you found it? So many different things. All right, we've got three out of five. The next sauropod is a new eusauropod, Jin Chuang Long. This was published in Scientific Reports by Ning Li and others. So the full name is Jin Chuang Long Niedu. And this eusauropod lived in the middle Jurassic in what is now Gansu Province, China, in the Xinhu Formation. The fossils were found in 2017. They found a partial skeleton, including a nearly complete skull and lower jawbone, a mandible, as well as the first five neck bones or cervical vertebrae and the last 29 tail bones or caudal vertebrae. There's about a 16 foot or 5 meter gap between the neck and tail and in that gap are impressions of the hips, the pelvic girdle and sacral vertebrae. The skull is about 12 inches or 32 centimeters long and it looks similar to the skull of Mementosaurus. It had a broad snout although that might be from taphonomic deformation, like it got smushed during fossilization. It's estimated to be 33 feet or 10 meters long. There's a lack of fusion in the bones, so it probably wasn't skeletally mature. It wasn't done growing. It's possibly a juvenile. Now, sauropod skulls tend to be fragile, so they're rare, especially non-neosauropod eosauropods. Like momentous aurets, in other words. Yes, or just eosauropods. So this find helped show that there were more sauropods in the middle Jurassic and what's now China. The authors wrote, quote, In contrast to the isolated eusauropod reports in most other global regions, the high rates of morphology, diversification, and distribution of eusauropods in these areas may indicate East Asia as a potentially important origin region of some sauropod clades, end quote. Yep. Seems like everybody's fighting over like, no, it started here. No, it started there. It just seems kind of pointless. Well, it's a good thing to know. It is. As for the name, the genus name Jinchuanlong means Jinchuan dragon. It refers to where it was found. The species name, Yeju, means Nickel City, and that refers to Jinchuan being famous for its nickel resources. The Nickel City. The Nickel City Jinchuan dragon. Last but not least, you mentioned Mementosaurus. We've got a new species of Mementosaurus. Mementosaurus sangianensis. This was published by Hui Dai and others in Scientific Reports. Mementosaurs, of course, we have talked about. They're known for those extremely long necks. In this case, they found a partial skeleton from the Sha Shi Miao formation in Chongqing, China. The exact age of the formation is controversial, but it's potentially from the late Jurassic, about 163 to 157 million years ago. The holotype includes the last two neck bones, or cervical vertebrae, a complete series of 12 backbones, parts of the hips, the first four tailbones, or caudal vertebrae, and a nearly complete left leg. It's different from other Mementosaurus species because of additional depressions on the backbones and a ridge on some of those backbones. The species name refers to the Hechuan District, where the fossils were found, quote, at the meeting point of the Jialing, Fu, and Chu rivers in Chongqing. Sanjiang means the three rivers in Chinese pinyin. Many sauropods have been found in what's now China that lived in the late Jurassic. There's at least seven genera and more than 17 species, and there may be even more because there's some unnamed material. Most of them are mementosaurids, and this new discovery helped show that there's even more mementosaurids. Oh, good. So those are the five new sauropods? Those are the five new sauropods. we have much more sauropod shindig left more sauropod shindig to dig I was thinking of the festivity side a bit more oh yeah that's true too but first we want to thank our sponsors this episode is brought to you by Squarespace Squarespace is a platform where you can scale your business or if you're just starting out you can claim your domain and like we did when we started inodino.com pick a name for your company where you can also get the domain. It does make things easier. And then once you have the domain, you can use their cutting edge design tools. They have a library of professionally designed and award-winning website templates for every use, every category. I'm seeing as I scroll through, if you want to show off your portfolio, they've got that. If you are selling things online, they've got that. They've got a whole category for media and podcasts. Nice. Yeah, both Sabrina and I did some web design decades ago. Maybe one decade ago. Well, I did some in the early 2000s. And back then it was like set up your table, tediously pick the amount of padding and the number of pixels of width and try to put it everywhere and then check it on a bunch of screen sizes and watch it break and then redo it and just keep doing that over and over again so you get something that looks decent. Yep. But now if you use something like Squarespace, They've got intuitive drag-and-drop editing and a whole bunch of styling options. What we used to call WYSIWYG. What you see is what you get. Don't have to be us a decade or, I guess, more ago. Yes. So when you're ready, head over to squarespace.com slash IKD for a free trial. Use that code when you're ready to launch IKD, and you'll save 10% off your first purchase of a website or domain. Again, that's squarespace.com slash IKD. This episode is brought to you by Squarespace. Squarespace is a website platform where you can find and claim your domain, showcase what you have to share with the world, and grow your brand as well as get paid all on their single platform. That all sounds great. It does. One of the ways you can grow is with email campaigns, which is really great that it's all included with Squarespace because there are a lot of options out there, but it can be overwhelming. So with Squarespace, they have all the tools you need to engage people, promote your services, grow your business, and you can set up automated emails and schedule them out so that they come out at just the right time. Yeah, it's really nice that that's integrated. Back when we started our website, it was not. And Sabrina had to do a lot of work to figure out how to do this. It's nice that it's integrated in one place now. We have a domain with Squarespace that we have been using for quite a few years, and it has been worry-free. We haven't had any issues with it going down or losing anything at all. It just has been working tirelessly for years without any input from us, which is exactly what you want when you have a website up online. So check out squarespace.com slash ikd for a free trial, and when you're ready to launch, use our offer code, ikd. to save 10% off your first purchase of a website or domain. Again, that's squarespace.com slash ikd. So we have covered the newest sauropods, at least as of this recording, and the classification of sauropods. Now seems like a good time to talk about other parts of sauropods, starting with the big part, that they're so big. The big part is that they're so big indeed. We had an episode, episode 486, titled How Dinosaurs Got So Big, which obviously focused a lot on sauropods because they were the biggest ones. The largest sauropods were at least four times heavier than the largest land mammals. To give a perspective of, you know, compared to animals today, the largest sauropods were at least four times heavier than the largest land mammals. Although the largest land mammal isn't around anymore. So if you compare it to the largest living land mammal, it's more like 10 times. Oh, good point. And some sauropods we've talked about before, they're estimated to have been up to 190 feet or 58 meters long. In terms of the tallest sauropod, that could go to sauropocidon, with giraffetite in proportions bringing it to an estimated 56 feet or 17 meters tall. That is extremely tall. And then the biggest sauropod of all time may have been Maripunisaurus, which was originally thought to be Amphicillus. And that's the one that's up to 190 feet or 58 meters long and weighing 150 metric tons or 170 short tons. Yes. So Maripunisaurus was the one that was lost. So it was renamed based on drawings, but Amphicillus was a preexisting name. And then from those drawings, they decided, okay, it looks different than the pre-existing genus Amphicillus. So they renamed it to Maripunisaurus, the really famous Amphicillus specimen. But those range estimates are highly disputed, I would say. It's hard to work with fragments and pictures. Yes, and this is purely pictures because, well, not even pictures, drawings. So the scale has been questioned because you're looking at a hand-drawn scale bar next to a hand-drawn vertebra, and it's claimed to be a couple meters for a vertebra, which would lead to a very large individual. But that assumes that it had the same proportions as something like Diplodocus or something very long, whereas other people have said, well, it might have had different proportions, and then it wouldn't have been nearly that big or that heavy. There are other estimates that are much smaller, but I'm going for the biggest ones because we're talking about how big sauropods are, which brings me to the possibly heaviest sauropod, Bruhathchaeosaurus, which one 2023 estimate was saying it could be between 120 to 190 tons. That is very big. Yes. But we get into all of those details and the debates and everything in that episode of how dinosaurs got so big. But how did they get so big? It's probably due to a few factors. So dinosaurs laid eggs, and that meant that their eggs or their hatchlings could start out small and then grow. They also had bird-like respiratory systems, which means that they had lighter bones. They had those air sacs to stay lighter. And they efficiently inhaled their oxygen. They had the bird-like lungs, which means they could continuously take in oxygen. And these things all helped them or allowed them to get big. Yeah, the breathing, I think, is one of the keys. because like when we're talking about momentous sores and how do you breathe with such a long neck, if they had tidal breathing like we did, where we breathe in and then we breathe out, they would almost surely asphyxiate in the process of breathing out and then before they could breathe in the next air to their lungs. Right. But their fancy bird breathing system means when they breathe in, they not only fill their lungs, but they also fill air sacs within their body. and the air sacs are really what change, change shape, I should say. And then their lungs are a fixed size. They don't actually change over time. And then when they breathe out, the air sac air gets pushed into the lungs. The lung air gets pushed out of the mouth. So they're getting new fresh air from their air sacs. And then when they breathe in, it goes the opposite way. So the air moves back out of the lungs into the air sacs, and you get fresh air coming in as well. So, yeah, always continuous fresh air. They don't have to worry about holding their breath or not getting oxygen while they're doing those deep breaths through that super long neck. Yes. Probably a key adaptation to being able to have such a long neck. And it's a good thing that they could grow so big so fast because that means that they were less likely to be preyed upon. Just as a side note, sauropods could eat a lot. That's probably not surprising. How else do you grow? Mm-hmm. In episode 522, we talked about how they digested, and it turns out that not many sauropods have been found with unambiguous gastroliths. I mean, the number's in the dozens, but that's not many compared to, think about how many dinosaurs have been found. Yeah, so they might not have needed gastroliths. Maybe they just could keep the plants in their gut for so long, like a compost bile, that it would just decompose without too much extra grinding. Well, also of the dozens of sauropods found with gastrolists, scientists have found, and gastrolists are like you swallow rocks to help grind up the food in your gut. Like chickens? I mean, chickens do that, not grinding chickens in your gut. That's confusing, yeah. So scientists have found that the gastrolists with these sauropods, though, they weren't capable of acting as gastric meals. They couldn't grind up the food because the weight of them was like 0.03% of the body weight, so it just couldn't help much. Yeah, and it might have just been that they got swallowed incidentally more than intentionally. Exactly, or maybe they needed minerals like calcium, because to grind up the food, the sauropods would need to have several hundred gastrolists, and they're often found with under 10. Or maybe the gastrolists got destroyed or transported during the fossilization process. Or it could be like maybe we just don't recognize them when they're getting collected or they got moved by scavengers. However, the simplest explanation seems to be that they just aren't there. So maybe instead they had big guts. So going back to being big. So according to one study, sauropods evolved gigantism 36 times over 100 million years around the world on at least six landmasses and in at least five not closely related clades or groups. So they were always going to be going for big. Well, it seems advantageous. the selective pressures pretty often pushed them to be big. And they had the ability, they had some of the features that helped them be big, like you were saying how they breathe, but also the availability of food. Probably a factor would be things like their metabolism and just whatever sort of growth factors they had in their body. Yeah. And their ability to support all that weight, too, with how their arms and legs were structured. Yeah, and they started getting big early on. We talked about this in episode 386, where there was a study of an indeterminate sauropodomorph from the late Triassic, this is early days, in what's now Brazil. They found evidence that it became large early on because this specimen was larger than most sauropodomorphs that lived around the same time or earlier and quote about 3 times heavier than buriolestes the earliest branching sauropodomorph they estimated it to weigh about 46 pounds or 21 kilograms compared to buriolestes which is about 15 pounds or 7 kilograms it's quite a bit bigger Yeah. It still had the slender hind limbs, well, slender legs and limbs proportions so it could run like other sauropodomorphs, even though it was still pretty large. They said that this specimen could be, quote, one of the oldest examples of body increased size within sauropodomorpha. And it could also be that the smaller sauropodomorph specimens that we know of are just not fully grown and maybe they were larger than we currently think they were. Yeah, the adults of those species. Yeah, it's always possible. We've certainly seen that a few times in the past. Yeah. And sometimes they get synonymized, too, with a larger individual. But I should note that sauropods didn't all get big. There were quite a few clades that also got smaller when the selective pressures pushed them that way. Especially if they were living on, say, an island. Yeah, there's some island dwarfism going on. There were others that got smaller, too, that weren't necessarily limited by islands. They were just smaller than their ancestors because there were some huge Jurassic, late Jurassic ones in the Morrison and things. But all those lineages don't just get bigger and bigger and bigger the way copes rule. Copes rule in quotes because it's not a very good rule that dinosaur lineages just always get bigger. It doesn't always work that way. Sure. But the fun thing about sauropods are the big ones. Yes. Back to that. In terms of how they became so big, it could also have been because of the soft tissue pads on their feet. We talked about that in episode 410. And these pads on the feet happened by the late Triassic to early Jurassic. So, again, early on, the authors in this study hypothesized that they had the soft tissue pad on the feet, which helped with their weight and to reduce bone stress. Yeah, definitely makes sense. That would be an adaptation, especially if it's that early in sauropod evolution, then the descendants would have the genes potentially to use that feature on all those different branches to get large. It's possible two sauropods had more soft tissues, like muscles, tendons, ligaments, and other things like that, with the potential for absorbing loads on the feet, like the heel. So with the sauropods, the heel hits the ground first and then absorbs the loads, or distributes forces evenly between its limbs. Walking on all fours is also important for being able to grow so large. And we talked about that with the discovery of the sauropodomorph Ledumahadi back in episode 201. That one weighed about 12 tons. It was from the early Jurassic, and it was the largest known dinosaur from that time. Yeah, it was huge. It was very surprising that there was such a big sauropodomorph. And the conventional thinking to that point had been, well, sauropodomorphs could reach a certain scale, but in order to be true massive sauropods, they had to change their posture a little bit and have their limbs a little bit more directly underneath them, or as you call them all the time, columnar limbs. Yeah. But Ladumahadi had a more sprawling posture. Its limbs were not directly underneath it. They were a little bit more spread out, kind of like the early representations we see of dinosaurs or like how lizards are not quite that much with like the belly dragging. Also a little bit how Triceratops probably had its front limbs a little bit out to the sides. And it showed that it wasn't a true limitation of that posture, that you could get to this greater than 10-ton scale, even without some of the later adaptations that the Neosauropods had for the columnar limbs and all that kind of stuff. Yeah. And then you could get giant and way over 50 metric tons. Like, there's at least five Titanosaurs that were that big. You've got Patagotitan, Argentinosaurus, Notocolossus, Puertosaurus, and Dreadnoughtus. That is very big. Yes. Oh, and then a new one that we talked, well, new at the time when we talked about it, in episode 479, Busting Gory Titan, which was estimated to weigh 74 tons or, well, 67 metric tons. Real big. Yep. I like that demarcation that you did. the group that are probably over 50 tons because the exact measurements of them is very difficult to do. It's all estimations and there's a lot of assumptions that goes into it. So just saying like these were the biggest ones rather than this specific one was the biggest is a good way to do it. Although it is fun to point out when we think. Everyone wants to know which one was the biggest. That's true. Yeah. We may never know the biggest. Yeah. You could know the longest if you had complete skeletons of them, but you're not going to know the heaviest because we don't have enough soft tissue to know for sure. Well, even the longest, we don't know what we haven't found. That's true. The longest complete skeleton we've found so far. Yeah, exactly. I will say, even though it is fun to talk about how big sauropods could get, there were some downsides, which we talked about in episode 447. I think this was the fun fact, Garrett. Oh, the getting struck by lightning? Yeah. Yeah. We were actually just talking about that two episodes ago with Bob Nichols with the art that he did of a sauropod getting struck by lightning and how it probably happened considering humans get struck by lightning standing in open fields were tall enough to aid in that electron distribution. So sauropods almost certainly were tall enough to be in trouble, especially since they, a lot of times, would have been by far the tallest thing in their ecosystem. They didn't have buildings around them. They didn't have lightning rods or things that were designed to dissipate some of that electricity. So, yeah, they probably got struck by lightning quite a bit. Well, also being around high trees, which they would have been trying to eat, that's a danger. Yeah, yeah. Yeah, exactly. You would think, well, maybe they weren't as tall as the trees, but the fact that they probably wanted to be around trees at all would mean that if the lightning struck the tree, they could get that side lightning where it sort of hops off of the tree into their body. And even if it doesn't, if it just goes straight down the tree, lightning running through the ground is really harmful, especially if there's a large space between your limbs contacting the ground. And with sauropods, they had a very large distance between their limbs. It sure did. So that is a very bad, bad news for sauropods. What I remember finding with looking through how you might want to survive lightning strikes in a environment where you couldn't go inside a building, because that's always the number one recommendation is get inside a building. What OSHA recommends for workers that are caught in thunderstorms without shelter that happen to be doing something like logging, they say you want to get low but not lying on the ground. So for sauropods, that would be like lowering their neck. But the other thing is if they could, you'd want to get to a dense area of smaller trees that are surrounded by larger trees. So basically the larger trees are more likely to get struck by lightning but you're not right next to those. They become the lightning poles. Yes. And so you want to be far enough away from those that you're not getting the ground effect of the lightning, but you don't want to be so far away that you're in a clearing and then you become the new tall thing. You don't want to be the lightning rod. And the odds that sauropods would know that is extremely small, I think. I don't think they would even have a selective pressure to, like the ones that know where to go when lightning strikes because humans tell each other this all the time, and we still forget it in the moment or don't recognize the threat of the lightning. So, yeah, I think sauropods are probably getting struck by lightning all the time. And then more sauropod carcasses for the carnivores. Yeah. It would be really cool if one day we found a bone and we could see some feature to it where we're like, this one got struck by lightning. Oh, yeah. Maybe that's why we don't find the skulls. They get hit by lightning and they explode. Explode? Oh, man. And that the legs are sturdy enough that they don't get damaged too much by this huge rush of electricity. That's definitely not what happens, but it would be funny. No, no. Well, assuming that the sauropod didn't get struck by lightning, it turns out that giant sauropod lived a lot longer than we thought. we talked about this in episode 509 where a team studied diplodocus and supersaurus they both lived in the lake jurassic and the morrison they're both very large and they took samples of their long bones and dorsal ribs the limb bone and rib bone and they found that they were skeletally mature when they died meaning they were done growing you can't count the lags to know how old they are because there's just too much bone remodeling with sauropods. But through other means, they were able to estimate that the Diplodocus specimen was at most 60 years old, which is older than other dinosaurs. There's been like a 40-year-old Camarosaurus found and a 50-year-old Carcharodontosaur Meraxes, which both of those are considered pretty old for dinosaurs. And their other means, just to elaborate a little bit on that, is there are still some lags. So they're sort of estimating where the other lags would have been if you could still see them, if it hadn't been all remodeled. Right. So there are much bigger error bars on these age estimates than there would be on a theropod or something where you can count most of the lags. But it's nice to have at least a rough estimate. Yeah. And even though theropods grew fast at first, the large ones probably took decades to reach their full size. So for example, Dippy, the Diplodocus took 24 to 34 years to reach 27 meters or be over 88 feet long. That's a Diplodocus carnegii species. But Diplodocus halorum, which was in this study, took 60 years to get to over 108 feet or 33 meters long. And then in the study was fun. They speculated that the supersaurus specimen was 225 years old, but there was too much bone remodeling. So they said approach this figure, quote, with extreme caution. Yeah. I'm not buying that one. Yeah. So moving on to the beginning of life for sauropods, after we're speculating how long they live. We're taking it in reverse order. Yeah. This is a new paper about a sauropod nesting site in Korea that shows that sauropods sometimes chose to lay eggs in fast-moving waters to protect them from potential predators. Yeah, that's a strategy. Yeah. This was published in Paleogeography, Paleoclimatology, Paleoecology by Song Young Kim and others. They found an in-situ sauropod nesting site that was only partly disturbed, so it is how it was when they were nesting. Yeah, found the way that they were way back in the Mesozoic. Yeah, they found 196 eggs on bar crests in a high-energy braided river. So bar crests are elevated regions of sediment, like sand or gravel, and then braided rivers go around those bars of sand and gravel. So it's basically like a sand bar. Yeah, and it's a fast-moving river. They found at least 25 stacked egg horizons, which shows that the sauropods selected these bar crests to nests. They put the nests on the sand or gravel. Huh, that's cool. It could be because it provides some protection. You know, it deters predators who don't want to deal with the fast-moving waters. The flood risk outweighs the predator risk. And they also would have been warmed by the sun. Oh, yeah, that makes sense. Because if you're looking for sand, it might be the easiest sand to find in the area because rivers are nice and silty. But I like that idea that it's like, ooh, that's good sand because predators can't get there. You could imagine some huge sauropod that's like, well, I can walk out there and some predator being like, it's not worth it. And then hopefully the eggs don't get washed away. Yeah, that's the key. Or buried and fossilized like they did in this case. Yeah. So modern birds time when they lay eggs. So there's a lot of food when the chicks hatch. And if sauropods did the same thing, like early summer, these braided streams would still flow during the nesting period and create a natural moat around the nests. Although you still have to worry about the flood events. Before this paper, the thinking was that dinosaurs nested on calm floodplains. There's been a lot of eggs found in those types of areas, but those areas are also more likely to preserve the eggs. I see. In this study, they found four types of eggs, or Ootaxa. There's a detailed study of them in progress. Some of the eggs are irregularly stacked, resembling a turtle nest. Turtles come up all the time. They do. Especially with sauropods. I was thinking turtles, too, when you were talking about how long they lived. Yeah. Well, if tortoises can live over 100 years, we're not sauropods. Yeah, that's true. Close relatives. The most common type of egg were the spherical ones with a lot of surface pore openings. No embryos were found. That's too bad. But based on the large size and being near sauropod bones, they think it's likely sauropod eggs. Yep. I mean, they had big round eggs. Yep. And did you say what time period we're talking here? Early Cretaceous in what's now Midwest Korea found in the Siwa Formation. Yeah, if we were in the Triassic or the early Jurassic, it would be like, yeah, there's lots of other big reptiles moving around. By the early Cretaceous, it's like, yeah, I think it's a fairly safe bet if you find a big, round egg. It's likely to be from a sauropod. Yeah. Oh, some of the layers are filled with sand, so it's likely those eggs hatched, and then the empty eggs were filled with sand, and then later a flood eroded the nest and deposited some coarser gravel around the sand-filled eggs. Okay. So maybe they didn't all get just buried and fossilized. We found no embryos, so. Yeah. Maybe they all made it out. Maybe. Good job, sauropods. Maybe. Unless they just got broken with the embryo inside and then filled with sand. Always taking the sad outlook. I'm just saying. We don't know. We don't know. So think what we want to think. I guess. It's not really very scientific, but I suppose. Yeah. So this site, the paper said, quote, provides the first clear paleontological evidence of previously unrecognized adaptive flexibility in sauropods demonstrating sophisticated reproductive strategies that parallel modern reptiles and birds, which select elevated mid-channel bars to mitigate ecological risks. Oh, I didn't realize birds did that too. Yeah, modern birds. We mentioned it. Oh, I guess I was just thinking about dinosaurs the whole time. Well, you were. That's true. Oh, I guess I just mentioned that they lay their eggs with lots of food. But yeah, birds do this too and reptiles. And the paper says, quote, Our findings highlight that such strategic nesting behaviors may have deep evolutionary origins extending back into the Mesozoic, offering valuable insights into dinosaur reproductive ecology under extreme environmental instability. End quote. Yeah, I like that saying if there's environmental instability, because you could imagine a situation where they would usually go to a place to lay eggs, and then the shore isn't really there for whatever reason. And there was a big flood or a bunch of plants grew or something else happened. So you need to adapt. So you need to adapt. And then you go like, well, there's a sandbar over there. I guess I could lay them in the middle of the river. Yeah. But also that idea of avoiding predators is really interesting to me. It's so hard. You can't say which one it is, though. It's either they saw sand and they were like, I like laying eggs in sand. Or they were more careful about the selection and thought, well, where's the best sand to lay the egg? Oh, that sand might help. Keep away predators. I'll go over to that stand. I mean, animals tend to put a lot of thought into where they lay eggs, even animals without super large brain power. So it's reasonable to think that it might have been totally intentional. Yeah. Pretty cool. It is cool. So our next paper has embryos and hatchlings. These are massospondylus embryos and hatchlings, which give insights into how early sauropodomors likely were on all fours before growing up and walking on two legs. Yeah, I always mix up Massospondylus and Musaurus for this reason, because they both have evidence of that, and they both start with M's, and that's how my brain works. Yes. So this was published by Ethan Mooney and others in Swiss Journal of Paleontology, and it's open access, so we'll have a link in our show notes. And they mentioned that sauropodomorphs were, quote, most numerous, diverse, and globally distributed dinosaurs by the end of the Triassic period, end quote. And it's likely because they were large, they grew quickly, and they shifted to eating plants, and they were in herds. I didn't realize they were basically the most successful dinosaurs by the end of the Triassic. Yeah, I mean, it makes sense because we didn't even have ornithischians, or neornithischians, whatever you want to call them, in the Triassic. So it's just theropods and sauropods at that point. I guess being a plant eater was more advantageous. And we also think they might have evolved first, so they had a little bit of a head start. And some of them were still probably omnivorous. So for this study, they found embryos, eggshells, and hatchling fossils of the sauropodomorph massospondylus, which massospondylus lived in the early Jurassic in what's now South Africa, Lesotho, and Zimbabwe. And it had a long neck and tail, a small head, slender body, and sharp, long thumb claws. Its arms were about half the length of its legs. There were two new embryos within eggs from the Elliott Formation in South Africa. Yeah, they were in this near vertical area and slightly higher than clutches of eggs that were easier to excavate. So only two eggs were collected while the rest are in situ. They're still embedded in the rock. They were collected a while ago by James Kitching. They weren't prepared and studied until now. James Kitching, just for reference, was a paleontologist who lived from 1922 to 2003. So probably collected sometime in the 1900s? Probably. There's also a hatchling tentatively assigned to Mastospondylus based on the large thumbclaw and its neck bones, also found in the Elliott Formation, but in a different part where the most common dinosaur found is Mastospondylus. And there was an isolated specimen collected in 1961 and was on display at the Ezeko Museum until 2003, but it was misidentified as Heliosaurus, which is a basal synapsid from the Permian. Oh, that's very different. It is very different. The thumb claw is straight in the embryo, slightly more curved in the hatchling, and then gets more robust and much more curved in more mature individuals, and it's unclear why. Hmm. Now, previous embryos found were estimated to be about 60% of the way through incubation. That's based on looking at the skull, the ossification. These new embryos, these two ones, were even further along, so that means you can compare how the embryos develop. Wow. So they compared the Massospondylist growth series onto genetic series with 22 other sauropodomorph dinosaurs, including Moosaurus and Qianlong hatchlings, also Buryolestes, Pladeosaurus, and Eorafter, just to name a few. And there seems to be strong similarities to these early diverging sauropodomorphs, the early sauropodomorphs, in terms of their body proportions, their posture, and likely their lifestyles. even though if you put them together they don't form a clay they're not closely related. They show that the embryos and hatchlings were on all fours in that quadrupedal posture. The embryonic tail bones were small and slender so they likely had a gracile tail and the proportions show that the center mass of the embryos and hatchling are more in the front of the hips so it would mean it's on all fours that quadrupedal posture again. They're also built to be more flexible than subadults and adults, so they had a bigger range of motion. And like Musaurus and Leofuncasaurus, they likely needed the Mastospondylous ones parental care after hatching. So they stayed either in or close to the nest, and they didn't necessarily need to be good at walking on all fours. And then eventually they transitioned to walking on two legs only as an adult, although we need to find an early-stage juvenile to figure out exactly when this shift happens. Some other late Triassic and early Jurassic sauropodomorphs where we know some of their growth stages show similarities to mastospondylists. There's only slight variations in proportions of the skull, neck, and limbs, and that may mean that early sauropodomorphs went through similar changes going from quadrupedal to bipedal, all fours to two legs. And that may mean that sauropods walking on all fours evolved through pedamorphosis where they're keeping a juvenile feature. I was just about to say that. Yeah. Which is funny that the largest animal ever to walk on Earth. Because of a juvenile feature. Yeah. Because the babies could do it. They were like, let's be like the little tiny babies and walk on all fours so we can get huge. Yeah. I mean, it's not a conscious thought, but it's funny that the evolution might have worked that way. Yeah. Which brings us to how sauropods moved. We talked about sauropod movement a little bit in episode So 524, Dinosaur Dancing and Movement, where there was one study in 2017 that found that Musaurus and a sauropodomorph that lived in the late Triassic in what's now Argentina that was originally thought to be small, turned out there were only juvenile skeletons found. And now we know they could get much bigger. And that they moved on two legs. So the palms of the front limbs faced inwards and its arm joints couldn't rotate downwards. They compared the front limbs of crocodiles and Musaurus, and then they reconstructed the anatomy and kind of compared the range of motion of the arms. And they looked at a bunch of muscles around the shoulder, elbow, and wrist joints. And it turns out that limb posture plays a big role in how the muscles work. They found that Musaurus could have maybe some active pronation of the hands, the way it could move its hands. But the muscles around that joint may have been too weak to do too much. Now, based on Musaurus, it seems that sauropods moving to all fours was linked not only to how the hands moved, but also by the forelimbs, the arms shifting into that more columnar posture. Now, once they're on all fours, how did they walk? Well, they didn't walk like elephants. We know that much. That's one of the key ways to identify a dinosaur documentary slash movie that really got into it with how dinosaurs walked versus one that didn't. because the ones that didn't do their homework often just have sauropods looking like big elephants. Yeah. I mean, that was the name of episode 384, and we talked about a study where they calculated or they figured out how sauropods walked, and they found that, well, sauropods have the Y gauge, so they can't just walk like, say, giraffes, where the right legs or the left legs move at the same time because there's a risk of them falling over, and then if they fall, they probably die because they're so heavy. Yeah, because their legs are too far to the sides. So if they lift both at the same time, it's really difficult to do. You have to lean so far over to keep the center of mass from tipping in the direction where the lifted limbs are. But instead, they probably walked in a diagonal couplet pattern, which is something you can see with beavers and hedgehogs. You move the front right and back left legs at the same time, and then you move the front left and back right legs, which is different from giraffes because they either have both right legs or both left legs moving at the same time and it's also different from elephants which move by lifting each foot one by one. The large sauropods, it turns out, may have had max speeds of 6 miles per hour or 10 kilometers per hour. This was published by Javier Ruiz and others in Scientific Reports, Open Access. Now it's hard to estimate the max speed of extinct animals, But for this study, they looked at the relationship between body mass and potential maximum speed, and they calculated it for sauropods and proboscideans, which includes elephants. And they estimated that for sauropods, their max speed was the 6 miles per hour, 10 kilometers per hour. That's for sauropods that are between 10 to 75 tons. That's a large range. It is. I guess that's about what we think. they usually imagine a sauropod going at. It's like walking, but covering distance a little bit faster than a human just because they have such long legs. Yeah. We know at least some of them walked at a steady pace. We talked about this in the last episode with different sauropod trackways, like the ones found from the middle Jurassic in Dewar's Farm Quarry. We also talked about that one set of sauropod tracks that show that it made a loop, which it might have been limping, but it's still cool that we could see a whole loop. I think we do have to talk about Sauropod next, because that's probably their main distinguishing feature, other than being so big. And tails. Tails, yeah. The necks we talked about in episode 465, Sauropod Fest. I guess that name was taken. It was. Well, also Sauropod Shindig was recommended, requested. There was a Michael Taylor and Matthew Wail wrote why sauropods have long necks and why giraffes have short necks. And sauropod necks were longer than they needed to be to reach the ground, like for drinking water. Whereas giraffes always look super awkward when they're drinking because they have to like crouch down weirdly. Yeah. At least the ones I've seen. So he talks about the air sac system that helps keep the necks lighter. They also had the vertebrae. The neck bones were pretty long, and some sauropods had bifurcated neck neural spines where they're forked. We see this in some birds like the ibis theristicus and ratites like the rhea. And these forked spines may have helped to stabilize and support the neck, although not all sauropods had them like most titanosaurs didn't. You do need a few features for your long neck to work, including being large, walking on all fours, having a proportionally small head, a lot of neck bones, and of course the air sacs in the neck to help keep it stable. And also lighter and also for breathing. Yeah. Air sacs are very important. Yes. Now giraffes, on the other hand, have shorter necks compared to sauropods because they have relatively small torsos, they're relatively large, they have heavy heads, and they only have seven neck bones as well as no air sac system. Now, that said, in episode 376, A New Velociraptor Relative with Hornets, we talked about how almost all known sauropod necks are incomplete and distorted. This was written by Michael Taylor. And the neck bones are just often large and fragile, and often the necks that are found are incomplete. It's trouble. Yes. From those lightning strikes. Maybe. Sometimes it's hard to tell if a neck is actually complete, too. So that adds to it. And for many sauropod species, we just don't know how many vertebrae are in a complete neck because the fossils found are scattered. They're not articulated. We don't even know how many bones are supposed to be there. Yeah. It's crazy how much it varies, too, from species to species, because basically every single mammal has seven vertebrae in the neck. So if you find half of them, you can pretty accurately estimate the size of the neck because you can just scale the other ones similar and you know how many to count. But with sauropods, there are species within the same genus where it's like one has 18 neck vertebrae and the other one has 23. Yeah. So it's just... Adds to the confusion. How can you ever know how long the neck is unless you find the whole neck? Because there could be more or less vertebrae than something that's super closely related to it. Yeah. It also doesn't help that some older specimens, the way they were prepared, it's hard to know what's real and what's been, as he put it, enthusiastically restored. To make it look nicer in a museum. Yep. Potentially bigger. Yes. So his conclusion was, quote, we are woefully short of sauropod necks. Yeah, we're always talking about missing sauropod skulls. We don't talk about how the necks are missing, too. At least we do know when the necks are longer and possibly longer than expected. because in episode 556, a recent one, we talked about that new early sauropodomorph way recursor, which is one of the oldest known larger longer neck sauropodomorphs. And its neck bones are longer, like the ratio of the neck bones are longer. And previously the thinking was that sauropodomorphs were small and had shorter necks, and then there was this gradual transition to the long necks. But this sauropodomorph already had the long neck and a small skull compared to other sauropodomorphs that lived around the same time, which we know is important for long necks, as well as robust legs, flender hips, and short arms with large hands. So this find shows that from the beginning, the long-necked dinosaurs were large and their necks were lengthening. Now, what can you do with a long neck other than reach food higher up? Well, this might be one of my favorite speculations or hypotheses. This is from our episode, Why Brontosaurus is the Best. We talked about how instead of fighting with tails, Brontosaurus may have fought with its neck, the Bronto smash, which Mike Taylor and others proposed in 2015. And because Brontosaurus and Apatosaurus, they had such thick necks that were reinforced and robust cervical ribs. Basically extra bones that run along the length of the neck. Yeah, the idea is they could have used their necks to crash down or sideways into their opponents, which is somewhat like a giraffe-style combat where the head's the weapon, although with Brontosaurus and Apatosaurus, the skulls were fragile, so not exactly. It's more like with elephant seals, where it's more towards the base of the neck, although it's hard to know in Brontosaurus how much soft tissue padding it had. So the question is, why have the big heavy neck when it takes so much energy to grow, maintain, and use? And the answer could be, well, to fight. Yeah, intraspecific fighting. Yeah. A lot of times in the animal kingdom, these big fancy features aren for fighting off predators or hunting prey It for impressing mates Yeah and fighting each other Yeah and fighting rivals So maybe that what the big I mean it would be completely expected to grow some big crazy feature for that purpose. I love the Brano smash art. It looks pretty, when you see it, you're like, yeah, I see animals do stuff like that. The tail smacking always seems kind of weird because you don't see very many animals using tails as weapons. but necks in the front of the animal. Unless you're an ankylosaur. Yeah, that's true. They don't have much neck. They're special. So how else did sauropods defend themselves? Well, now we're on to the tails. There's a nearly complete Pladeosaurus tail that shows that this sauropodomorph could do damage with its tail. This is a new study? It is a new study. It was published by Thomas Felleck and others in Royal Society Open Science. It's called Tale of Defense. How do they spell tail? T-A-I-L. Okay. Yeah. Proper pun style. Yeah. Now, there's a partial skeleton of Pleiosaurus found in 2015 in Frick, Switzerland, and then mounted at the Natural History Museum of Vienna in 2021. There's no skull, but there are 188 bones from the skeleton, including an almost complete tail with a, quote, well-preserved, articulated, whiplike, distal end. Hmm. They said it was an exceptionally rare articulated tail tip. The total tail length is 196 centimeters, over 77 inches, and the whip-like tail tip is 60 centimeters, or over 23 inches. And there's 43 tail bones. Now, Pladeosaurus is estimated to have 45 tail bones, and for the tail to be about 45% of its total body length, and the thinking is that it held it horizontally. So, yeah, 43 tail bones is pretty good out of 45. Yeah, and I'm looking at the pictures of the tail, since, like you said, it's open access, the bones in the middle of the tail look like they're well over 10 centimeters or a few inches long, whereas at the end of the tail, they're like one or two centimeters. And so much shorter and smaller, you know, you could put together about 10 or 20 of those at the end of the tail to get to the mass of one of the bigger vertebrae. Mm-hmm. So, and it kind of shows you, too, that the exact number of vertebrae doesn't necessarily matter too much if you're missing some of the really small ones. Because if you say this one had 45 and this one had 60, if the difference is in that end of the tail, it might only account to a meter of length difference. Yeah. Oh, also, while they were preparing this, they found a theropod tooth unexpectedly attached to the hip bone of the plebeosaurus. Now, a lot of pletosaurus skeletons have been found, over 140 at least, which I didn't realize there was that many. And they ranged from 4.8 to 10 meters, or about 16 to 33 feet long, and weighed 600 to 1,000 kilograms, or about 1,300 to 2,200 pounds. Okay, so like a ton. Yeah, a good size. That is big. Some potential predators have been found in the area, like Lillian sternus, which was about 5 meters or over 16 feet long, 16.4 feet long, and weighed 130 kilograms or about 286 pounds, as well as Nodotesserae raptor, which was about 3 meters or 10 feet long. It's not clear if Palladiosaurus was actively hunted or if it was scavenged or if it was just found together from taphonomy, how the bones fossilized. Oh, meaning if Pladeosaurus and that theropod tooth? Yeah. Well, if the tooth was attached to the hip bone, but anyway. It could get attached later. I mean, depends how it's attached. Yeah. If it's not stabbed into a tooth-shaped hole, and it's just sort of stuck to the outside of it. Now, Pladeosaurus had long curved hand claws, likely for grasping, but it could also be for defense, and maybe it whipped its tail for defense. They reconstructed the tail with the tail bones, the caudal vertebrae, and they analyzed how well it could whiplash. And they compared it to Diplodocus, that's probably the most famous whip-like tail one. Oh, yeah. As well as a modern Asian water monitor and a green iguana. And they found that Plataeusaurus's tail was very flexible, and it could move the tail quickly, similar to modern reptiles with rapid strikes. Plataeusaurus's tail was shorter and more robust compared to Diplodocus, which favors force over speed. So Plataeusaurus would have had slower but high-impact blows. It could still be very effective. It could be. Because you don't have to break the sound barrier to not want the point of a tail poking you in the eye. That's true. They did say there's limitations to the study, like the assumptions used for calculating kinetic energy or how much energy is used to move the tail. And there's no direct fossil evidence that it used its tail for defense, but it does seem possible. Yeah, I hadn't heard about the flexibility before. That's a very interesting aspect to it, and something that you can't know unless you actually find those bones. Yeah. And sauropod tailbones have bony ridges that may have helped them use their tail as a weapon or just signal to other sauropods. We talked about that in our dinosaur dancing and movement episode. In one study, they only found bony ridges in the tailbones of sauropods, and they were long and they varied in size and position. And similar bony ridges have been found in some modern rayfin fish, longfish, and amphibians, and they're known to be bony spinal cord supports. So maybe with the sauropods, it helped keep the spinal cord stable while it was moving its tail, especially if it's using it as a weapon or for signaling to other sauropods. Speaking of tails, it turns out there's another sauropod with a tail club. We already talked about maybe shoonosaurs. This one we mentioned first in episode 518, and this sauropod is Cotosaurus. It lived in the early to middle Jurassic in what's now India. There's only four sauropods known to have tail clubs, or thought to have tail clubs, I should say, because you've got Shunosaurus, Omeosaurus, Mementosaurus, and now Cotosaurus. And Cotosaurus had a tail club similar to the tail clubs of two sauropods found in China, the Shunosaurus and Omeosaurus ones. And this is the first example of a sauropod tail club outside of China. At least they're thought to have tail clubs. Right, right. Because we haven't really determined just how clubby those tails really were. Yes. And what covered those tails was skin. Hopefully, yeah. Which brings me to our next segment. Well, we first talked about this in episode 385, Sauropods with Goosebumps. And scientists re-examined Hastesaurus skin and found scales and structures that looked somewhat like goosebumps. And Hastesaurus was a macronarian sauropod that lived in the early Cretaceous in what's now England. these laser imaging to study this, and they think the scales are likely from the left forelimb, or left, I guess, arm. It's possible that it helps with regulating body heat by increasing surface area. It's also possible there's a link between these structures on the skin and sauropods getting bigger. Removing more heat as they get bigger, I guess. Yeah, but this isn't the only sauropod that's been found with some skin. And there was one Diplodocus specimen described in 2021 where they found six different types of scales. They had large polygonal scales, pebble scales, rectangular scales, egg-shaped scales, dome scales, and some irregular scales, which must have been an interesting pattern. Yeah. Yeah, a lot of times it's different parts of the body, depending on how things need to be flexible. Yes. Now, sauropods did get injured and sick sometimes. I mean, all dinosaurs did. All animals did. Mm-hmm. One of the most famous examples, I think, is poor Dolly. Is that the nickname? It's not just Dolly anymore. It's poor Dolly. To me, yeah, poor Dolly. Yeah. This was from episode 379. Yeah, we had the first evidence of a respiratory infection with Dolly. The Diplodokid. Yes, Dolly the Diplodokid. I feel like it was a Diplodokis for a while, and then it got brought into Diplodokid. But Dolly had those, as we called them, broccoli-shaped growths in some neck vertebrae. And basically, the long story short is that it may have had air sacculitis. And itis is a suffix that means inflammation. So that means inflammation of the air sacs. And since it's a neck vertebrae, it would be the air sacs in the neck which got inflamed. You can think of it as similar to bronchitis, but rather than being in the bronchial tubes, It's occurring in the air sacs. And modern birds get air sacculitis, which is how we can make this comparison. In the case of Dolly, that air sacculitis probably would have gotten caused by a bacteria or a fungus. And then over time, that infection got bad enough in the air sacs that it spread to the bones. And that's where you get the osteomyelitis. This is another itis, meaning bone swelling in this case. Worse. Yeah. Yeah, and the only thing that got preserved, obviously, is the osteomyelitis because the bones preserve, but the air sacs usually don't preserve or maybe ever. I can't think of an actual preserved dinosaur air sac. So it's possible that it was something else that caused osteomyelitis because other types of infection other than respiratory infections could cause that. But because the infection seems localized to a few neck vertebrae, it seems to be the most simple explanation that it was a respiratory infection, especially since we know birds get infections in their air sacs. Yeah, I remember that paleo art where it kind of shows Dolly coughing, runny nose, there's flies around the head. Yeah, it sounds like a nasty one. Yeah. It's possible that it killed Dolly directly, but it may have also just weakened Dolly so that they were a better target for predators. Although, if you were a predator, would you want to eat a clearly sick animal? Probably. I mean, you're eating like a leg or something. Oh, yeah. Stay away from the runny nose. Yeah. Especially, yeah, if it's like a runny nose. If you see like lesions on it or something or the meat has some like parasite in it, then yeah, you'd want to stay away from it. But if it just has a runny nose, it might not scare you off. So we have talked about what sauropods looked like, how they moved, infections. The last bit we want to cover is sauropods on display, because you see them at a lot of museums. You do have to have a lot of space. Yeah. Yeah, when we fantasize about one day having a dinosaur museum, the space is the difficult part. Yeah. Not only do you need a high roof to fit basically any large dinosaur people are interested in, because they tend to be over 10 feet tall, but in the case of sauropods, you're either curling it up into several revolutions, like coiling up a snake or something. Which is not accurate. Yeah, which probably isn't. Although some of them were pretty flexible in the tail, like we were talking about. Oh, that's true. Plagiosaurs. Yeah. Or you're doing scale models or you're missing part of the animal or something. Because, like you said, they're very big. Well, the first sauropod ever put on display was Apatosaurus or maybe Brontosaurus. We talked about this in episode 428. Technically, Dippy the Diplodocus was on display first, but it was only on display for a couple days and not open to the public. So I'm thinking maybe that one doesn't count. Oh, yeah. It was just like set up in a room to sort of test it out. Yeah. Show it off for a little bit. And that could have been done elsewhere, too. That's the kind of thing that people would end up doing before putting a big public display out there. But this one's documented for Dippy. Yes. The Carnegie Museum Diplodocus, speaking of Dippy, has an interesting history. And if you're a patron, maybe you already heard us talk about that in our latest Dino Download 10, which was about dinosaur art. If you're not, you can join patreon.com slash inodyno and give it a listen. There's some papers about it, and, quote, It is known around the world primarily because of a single skeleton, that of the Carnegie Diplodocus, because the millionaire industrialist Andrew Carnegie had casts of this specimen mounted in nine prominent cities around the world between 1905 and 1930, end quote. And there are 10 casts. They were sent to London, Berlin, Paris, Vienna, Bologna, St. Petersburg, La Plata, Madrid, Mexico City, and Munich. Yeah, I remember that detail being that like Carnegie or Carnegie was trying to do a sort of dinosaur diplomacy. It was like if everybody has these dinosaurs and they're enjoying that together, maybe they'll all get along. Yes. The original fossil was also mounted in 1907 at the Carnegie Museum, and then it got remounted during a renovation in 2005 to 2007. And it's a composite of eight different individuals. There's fossils from four specimens and casts of bones made based on other specimens. Lots of the mount are casts or sculptures, including the skull and lots of the tail. The current mount is about 26.1 meters long, over 85 feet. Although no one really knows how long this dinosaur, the mount, is, according to Mike's SVPow blog post. It's surprisingly hard to measure, and the tail may need to be longer. Yeah, there's a lot of that, like you were saying, missing vertebrae, but there's also the question of how far apart the vertebrae were. If you add an extra inch between each of 30 or 50 vertebrae, You're adding several feet to the length. Yeah. Now, in 1902, King Edward VII of England paid a surprise visit to Carnegie at Skibble Castle in Scotland, likely to get inspiration from Carnegie's castle for renovating palaces, and he saw the skeletal reconstruction of Diplodocus and requested a specimen for the British Museum, which is now the Natural History Museum in London. They ended up making a mold so they could make multiple casts, and the idea, like you were saying, Garrett, was to send multiple kings to get support from them to, quote, advanced peace arbitration, the main focus of Carnegie's philanthropy at the time. There is also a concrete cast of the Diplodocus, which we talked about based on Mike's paper in 2023 in episode 436 titled How Dinosaurs Became Birds Update. This concrete skeleton was first unveiled in Vernal, Utah, in 1957, and then it was outside the museum for three decades. And there's 600 pieces, some vertebrae made from eight or more pieces. Yeah, because there aren't 600 bones. Yeah, but when making it out of concrete, I imagined it's too heavy. They used wire and rods to reinforce it, and then they coated the cast bones in fiberglass. The skeleton was mounted on a steel scaffolding and reinforced, and it could withstand 70 mile per hour winds that uprooted nearby trees. I was thinking, why did they make it out of concrete so late in the 1900s when constructing out of fiberglass and other materials was well established? But if you're trying to make it wind resistant, lightweight things can get blown around. And if they're concrete, then you don't have to worry about that. I think that was just a happy bonus. I don't think that was the point. I don't remember why they decided to do concrete. I think they were testing it out. It might have been more cost effective. I'm not sure. It's interesting. I'll have to re-listen to that episode for why they did it, because I know we talked about it in depth. But the whole thing weighed eight tons. It took about a year and a half to create and cost $10,000, which is over $105,000 in today's dollars. Unfortunately, it's unclear what happened to the original molds after casting. Yeah, three decades. That's pretty good. But back to Dippy, in May of 1905, the Diplodocus was unveiled at the British Museum, again now Natural History Museum, and a lot of people gave speeches and there was a lot of press. President Theodore Roosevelt congratulated William Holland, director of the Carnegie Museum, and wrote, what a glorious shooting we would have had on Little Missouri had it, the Diplodocus, survived our time. Of course he would think of hunting. Yeah. That's very Teddy Roosevelt of him. Imagine if I could have shot this thing. Yeah. The mounted skeleton of the actual fossils was unveiled, like I said, in 1907 at the Carnegie Museum. There's some criticisms of its posture. It was standing erected and some at the time thought it should sprawl like a lizard. Yep, but it was a better choice to not make it sprawl like a lizard. Yes. But back to that brontosaurus at the American Museum of Natural History, that one took six years to mount. It was mounted in 1905 and then unveiled February 16th of 1905. It has been labeled both apatosaurus and brontosaurus. It's actually unclear which genus it belongs to, and I'm sure it also depends on who you talk to. And being from 1905, that makes it generally the official first mounted sauropod for public display. Yes. It's a composite of at least four different individuals, all from Como Bluff, Wyoming. And according to the Gotham Center, many curators were afraid of being compared to showmen like P.T. Barnum by putting up dinosaurs as spectacles, which they were wrong. Yeah, they thought, you know, science should be this like fancy highbrow pursuit of the upper crust. And do we want to, you know, diminish it by putting it on display like some sort of circus attraction? And it's a good way, it turns out, to get people interested in science. I don't know if these specific people would have wanted everybody to be able to be pursuing science. but if they were okay with that then they should be happy with the results. Yeah I think it worked out. Also who doesn't love sauropods? Yeah it's good to inspire children. Yeah. And we'll get into our dinosaur of the day. Shockingly it's a sauropod but first we're going to pause for a quick sponsor break. This is probably the last time you'll hear us mention that we're mailing out our Bahatosaurus patch very soon to all of our patrons at the Triceratops level and above. So if you haven't already joined and you want a really cool Bahatosaurus first ever sauropod patch even cooler than a Margosaurus, then make sure you sign up at the Triceratops tier or above by February 28th, 2026 because again, on February 28th we're just going to download all the names all the addresses and start the work of packaging them all up and sending them all over the world because we'll mail them anywhere in the world. So if you want to get your patch and you're already a patron, make sure your address is up to date so that it gets to you where you are and not to where you used to be. And if you're not yet a patron, but you want a super cool Bajadasaurus patch that you can't get anywhere else, then head over to patreon.com slash inodino and sign up at the Triceratops year or above by February 28th. Again, that's patreon.com slash inodino. And now on to our dinosaur of the day, Cediosauruscus, which was a request from Amatotitan via our Patreon and Discord, so thanks. Again, not to be confused with the sauropod Cediosaurus, although Cediosauruscus was for a while considered to be Cediosaurus. I don't like it. The genus name means Cediosaurus-like, and then Cediosaurus means whale lizard, so whale lizard-like. Yeah, it's definitely confusing. C.deoceriscus was a sauropod. It lived in the middle Jurassic in what is now England, found in the Oxford Clay Formation. It walked on all fours, had a small head and a long neck and a somewhat long tail. The hind limb is longer than the forelimbs, but not by too much. Its feet were similar to Diplodocus. Its first toes are large with claws and the outer toes are small and don't have claws. It was estimated to be about 49 feet or 15 meters long. So the whole body is about the length of a Mementosaurus neck and weigh between 4.4 and 11 short tons, depending on how it's classified. The biggest Mementosaurus, we should caveat, because there were Mementosaurus with much shorter necks. Yes. Now, in the past, C. dioceriscus was considered to be a diplodicoid based on its vertebrae being long. And then later, it was thought to be a Mementosaurid. But now it's considered to be a eusauropod, the much more general group. and I'm glad that we talked about all these classifications earlier in the episode. The first fossil was found by clay workers, and then it ended up at the British Museum of Natural History, now the Natural History Museum in London. The fossils include the forelimb, but no hand, most of the hind limb, a shoulder blade, parts of the hips, and the vertebral column, parts of the back and tail. In 2009, a leg bone was found at Cotswold Water Park, considered to also belong to Cediosuriscus, according to a news article. It took six months of sifting through muddy clay to get the bone pieces, which are 4.6 feet or 1.4 meters long. The site where the leg bone was found was being refurbished, and the spot where the bone was found flooded. Did it flood with water park water? I don't think so. Now, originally, C.D. O. Souriscus was considered to be ornithopsis by Hulk in 1887. Hulk described a partial sauropod skeleton that was found in England in 1887 as an ornithopsis specimen, a new species, ornithopsis leedsi. But then in 1871, Phillips named Cediosaurus oxoniensis based on an incomplete skeleton. And in 1889, Seeley said that ornithopsis leedsi and Cediosaurus oxonensis were the same, so the specimen that Hulk described in 1887 was considered to be Cediosaurus. And then in 1905, Woodward described another Cediosaurus skeleton. And in 1927, von Hewn found that the first specimen was most likely in between Cediosaurus and another sauropod, Hapocanthosaurus. Hewn said that the specimen was different enough to be its own genus, so he named that 1905 skeleton Cediosauruscus. And he implied with the name Cediosauruscus that it was similar to Cediosaurus. I don't like that, Hewn. He referred that skeleton and a hip bone from another individual to C. dioceriscus, and the type species at the time was C. dioceriscus leedzii. Then in 1980, A.J. Cherig found C. dioceriscus leedzii to be dubious. The hip bone was too incomplete to even compare to the hip bone from another skeleton, which meant that there was no more type species, so he proposed a new species based on the skeleton C. dioceriscus stewardi. I was hoping he would just let Cediosiriscus go away as a genus name. I guess not. He later petitioned the Icedian to make Cediosiriscus stewardi the type species, which includes the specimen Hume named Cediosiriscus 4. And they said no, because Cediosiriscus is a bad name, given a different genus name. No, they accepted it. Oh. So the type and only species is Cediosiriscus stewardi, and that species name stuwardi is in honor of sir ronald stewart chairman of the london brick company which owned the clay pit where the fossils were found there were other species in the past we had medius brevis brachioros and longus to name just a few but none of them were considered unique enough or truly diagnostic so they're no longer considered to be a species of cd osiriscus so at least we're only dealing with one species yeah there was another species originally ornithopsis Screpini, then later Cediosauruscus Screpini, but it was eventually named as a new sauropod, Amansia, in 2020, which we definitely covered because it's a new dinosaur. I remember that name, and I like it better than Cediosauruscus. I keep wanting to say Cediosaurus. Yeah, so some other dinosaurs that lived around the same time and place as Cediosauruscus include the Ankylosaur Sarcolestes, Stegosaurs like Lexovasaurus and Loracatosaurus, and the Ornithopod Calivosaurus. And some other animals that lived around the same time and place include Ixiosaurus, Plesiosaurs, Pterosaurs, and Crocodilians. And now, finally, the moment you've been waiting for, Garrett, our fun fact. I don't even remember what it is anymore. Well, it's that some sauropods could rear up for long periods of time. Oh, yes. This was published by Julian C.G. Silva Jr. and others in Paleontology and its Open Access. Now rearing up means being in a tripodal stance. You're standing on the back legs and using, well, not you, but sauropods are standing on their back legs and then using the tail for more support. And that's good for scaring off potential predators who look bigger and also eating leaves high up in trees. It might have also been good for mating. For this study, they analyzed seven specimens to see if they could rear up. An adult diplodocus that was about 7,000 kilograms or 15,400 pounds. That's an estimate based on its femur. Amargosaurus estimated to be about 3,000 to 10,000 kilograms or about 6,600 to 22,000 pounds, which is quite a range. Giraffa titan, which was around 30,000 kilograms or 66,000 pounds. So about 30 tons. Dredonatus, which was about 38,000 kilograms or almost 84,000 pounds. 38 tons. Yes. And there's also Eubarabititin, the specimen in that study is likely a subadult. The adults are estimated to be about 26 meters or 85 feet long and similar in size to Dredonatus. Then there's Australotitin, also similar in size to Dredonatus, and Nukensaurus, which was about 1,400 to 6,000 kilograms or 3,000 pounds to 13,000 pounds. So they digitally reconstructed the femurs of these seven sauropods, and they used a computational technique known as the Finite Element Analysis, or FEA, and estimated the stress of the femur, the thigh bone, from gravity and the weight of the sauropods when standing on their two back legs. How well could it handle it? And FEA can simulate stress, strain, and deformation in various structures in a virtual environment. So that's handy. Yes. It's the source of a lot of these analyses for, like, bite strength, and in this case, standing strength, more or less. Yeah, stamina. I think it's femur strength is really specifically what they were looking at. They found that two types of sauropods could easily stand on two legs for long periods of time when they were young. Uberabatitan, which that one is estimated to be up to 26 meters long, and Nucensaurus. And both of those lived in the late Cretaceous about 66 million years ago. They had more robust femurs. Uberaba titans, the titanosaur, and Nucensaurus is a seltosaurid, which seltosaurids have shorter necks and tails and robust hips. So it's possible that other seltosaurids could have reared up on two legs more often than other sauropods. Yes, so both of these are on the smaller scale, because Nucensaurus, I don't remember what weight you said it was, but it was pretty small. 3,000 to 13,000 pounds. Yeah, so, I mean, that's lighter than a lot of animals today, at the lower end at least. Yeah, which that makes sense that it can handle being on two legs. So they had the bone and muscle structure to stand on two legs. Larger sauropods could probably also stand, but for shorter periods of time, and it probably wasn't as comfortable because you got more stress on the femur. Like, dreadnoughtus had higher stress levels, and that's not surprising. The authors said that they did not take into account cartilage in the bones or how the tail might help them in the tripod position. They just assumed the role of cartilage was similar in all seven specimens. So maybe there'll be some future studies on this. Yeah, so really it seems like what this was looking at is which sauropods would be the most likely to rear onto two legs. And the answer was maybe not surprisingly the smaller ones. Yeah, although maybe the bigger ones could for a short amount of time. Yeah, but that requires a much more thorough analysis. Yeah. That's more of a complete reconstruction than just like how much stress was put out of the femur. Yeah. It's like I see this as laying the groundwork. It's a first study. So that wraps up this sauropod shindig episode. That was a lot of shindigging. Yeah. I enjoyed it. Thank you for listening. Stay tuned. In our next episode, which comes out in a couple weeks, we'll have an interview with Riley Black about her book, The Shortest History of the Dinosaurs. Plus, we'll be talking about a new Ceratopsian, and we'll have our first week of dueling dinosaurs. In the meantime, if you want to get your paleo fix, we have our I Know Paleo episode coming out next week about Titanoboa. So if you want to listen to that, make sure you join at the Triceratops tier or above at patreon.com slash inodino. Yeah, plus if you are at that tier, you're eligible to get the new Bahatosaurus sauropod patch. Yes, more sauropods! As long as you're a member at the end of February, 2026. Thanks again. And until next time. Before you go, a quick reminder that we are sending out our Bajadasaurus exclusive patches to all of our dinoidols at the Triceratops tier and above in March. So if you would like to get yours, make sure to join our Patreon at patreon.com slash inodino before February 28th. And if you want to see the patch, you can also see it on Patreon. I think it looks great, personally. Sabrina did most of the work, but I put on some finishing touches. And then, of course, somebody else printed it for us. Sewed it, maybe I should say. It's got really nice relief of the spines of the Hadasaurus, but of course now we think it had a sail around it, so that is also depicted. So check it out, patreon.com slash iKnowDino. As a listener of iKnowDino, you probably already know, science shapes every part of our lives, but so much of its influence is overlooked or buried in the past. Tiny Matters is an award-winning science podcast about tiny things from molecules to microbes that have a big and often surprising impact on society. And we've been enjoying listening to their episodes very much. From deadly diseases to forensic toxicology to the search for extraterrestrial life, host and former scientist Sam Jones and Deboki Chakravarti embrace the awe and messiness of science and its place in history and today and how it could impact our world's future. They tackle questions like, can we de-extinct a species, and should we? How was IVF invented? Why did the dodo bird really go extinct, and does life exist beyond Earth? Some of those topics sound pretty familiar. They do. A lot of good overlap here. New episodes of Tiny Matters are released every Wednesday on Spotify, Apple Podcasts, YouTube Music, or wherever you listen to podcasts.