Gigapods_ Answering who was the Biggest Dinosaur.

Within prehistory, there is few types of creatures more awe-inspiring and interesting than the group of dinosaurs known as sauropods. If you do not know the word sauropods, you certainly know what they look like. They were the largest land animals to ever exist, with massive elephantine bodies and their signature long necks, which they used to live a herbivorous lifestyle. However, how big could they get? If sauropods were the largest, who is the largest of the largest, the most sauropody of the sauropods? This is actually quite a hard question to answer. Most of the time, the largest sauropods, who I will informally call gigapods from now on, based off of PaleoNerd on DeviantArt's own name for them, share a few things in common. Firstly, they are huge, like huge huge, as in substantially longer than 30 meters long and heavier than 70 metric tons. But another signature part of this group is the fact they are known from incredibly scant remains. See, the problem with bones that are as big as the found in these animals is that it becomes exceedingly more difficult for the bones to fossilize. Because of this, there are so little bones from all of these animals, most are known from just one partial remain, and some just one fragmented bone. And most are so close in size that we really cannot label one as the biggest. Instead, the gigapods as a whole are recognized as possibly each being the biggest. So, let's get into all the individual gigapods. To immediately contradict what I just said, usually Argentinosaurus is titled the largest dinosaur and land animal to ever live. There are a few main reasons for it. Firstly, it is the original gigapod. Discovered in 1989 by an Argentine farmer and officially classified in 1993 by paleontologists José Bonaparte and Rodolfo Correa, it definitely started a lot of talk when as the largest dinosaur ever. Secondly, compared to others of its immense size, it isn't that incomplete. The Argentinosaurus holotype consists of several vertebrae, part of a sacrum, and fractions of some ribs, along with the first bone discovered by the farmer who owned the plot of land and subsequently led to the discovery of the rest of the fossil, a monster tibia, which was 155 centimeters long. In the time it has been discovered to the present, most size estimates float around 25 to 36 meters long and 60 to 100 metric tons, making it the heaviest sauropod and therefore dinosaur known for its substantial material. Now, throughout its discovery, many sauropods have tried to take the title of probably biggest dinosaur from Argentinosaurus, and most of these animals are from the same clade of sauropods that Argentinosaurus is from, Titanosauria, and in fact many are from the same region in South America, that is Patagonia in Argentina. Puertasaurus, discovered in Patagonia, is only known from four vertebrae, of which only one is complete. It could definitely take the title from old Argentinosaurus, but there is so little remains it is hard to say which one is bigger. Oddly enough, even though it's up in the air if it was bigger or heavier than Argentinosaurus, its oddly shaped vertebrae signify it was definitely broader than most others of its size. Voodoolongosaurus and Patagotitan are on the other side of the spectrum, as they are actually known from a pretty good deal of remains, but are probably just a bit smaller than Argentinosaurus. The United States contender for big titanosaur is a Llamasaurus, which could reach up to 30 meters and 73 metric tons, which is once more still slightly smaller than Argentinosaurus. See, the problem with some of these titanosaurs is that they are so close in the size range of Argentinosaurus that it could really go either way, and we really do not know the true answer just because of the fragmentary remains. Maybe the original Argentinosaurus holotype is just an outlier, we really don't know, but the fact still remains that Argentinosaurus size estimates just barely beat out most of its competition. Barosaurus was for a while quite an unremarkable sauropod, the most famous probably gotten as being the skeleton hanging in the entrance to the American Natural History Museum, you know, that one. Found in the Morrison Formation, it's not nearly as famous as its relatives who lived in the late Jurassic with it, like Diplodocus and Apatosaurus. Its average size was probably around 25 meters and 20 metric tons, and even though that's big, sorry pal, those measurements won't get you into the gigapods club. But everything changed when a massive cervical vertebrae was assigned to be a specimen of Barosaurus. By scaling a cervical vertebrae from an earlier Barosaurus fossil, paleontologists were able to estimate this one individual at 50 meters and 100 metric tons. That absolutely blows Argentinosaurus straight out of the water. Its neck alone would have been as long as a Brachiosaurus is tall. Now remember, this is one vertebrae from what in my opinion appears to be a massive, literally outlier. No other Barosaurus fossil comes near this guy. Of course, like I said before, you could then just as easily say that Argentinosaurus could be an outlier. After all, it is known from only one adult specimen. Or maybe sauropod necks grew throughout their lifetime, which is something thrown around a lot about the Barosaurus debate, if you look deep enough. And this guy's neck is just disproportionately large, making him overall smaller. See, this brings up a pervasive problem with trying to figure out who's biggest, which is we're looking at such little remains and so many unknown factors, it becomes near impossible to truly determine. But the fact still remains, this Barosaurus individual might have been the biggest land animal to ever exist. If you thought Barosaurus and Argentinosaurus specimens were scant and enigmatic, get ready for Brachiosaurus. Discovered near the southern tip of India in the late 80s, an ileum and an ixium, part of a femur, a tibia, a radius, and a vertebrae were described in 1989 belonging to the creature. Originally, the bones were actually labeled as belonging to a theropod, but this was quickly put down once they properly understood how large the fossils were. And indeed, these were some big bones. The tibia itself was two meters long, much larger than Argentinosaurus, it is 155 centimeter tibia. If scaled from Argentinosaurus, it would be around 44 meters and its weight would have been 126 metric tons, making it the largest sauropod. And one estimate put its weight up to 200 metric tons, which would make it heavier than a blue whale and therefore the largest animal ever. Now, there are a few things holding back Brachiosaurus from not just being the biggest dinosaur, but even a dinosaur in the first place. First off, it's hard to even classify the creature, as the paleontologists who found it never photographed the fossils and only gave rough line sketches of it, which left out many necessary details, known as diagnostic traits, which should allow them to put the animal in the correct taxonomy. Brachiosaurus is only grouped into Titanosauria because of its immense estimated size. As for if it even existed, the original fossils might not at all come from the same creatures due to the drastic size distance of the ileum and radius compared to the tibia, which was much larger in comparison. It might not even be an animal. Because of how damaged the fossils are and the fact most don't add up together, some speculate Brachiosaurus was just a fossilized tree trunk. So, because of the dubiousness of the fact if it was even an animal, most people do not count Brachiosaurus as being the biggest of the gigapods. Of course, you now ask, well, why not just look back at the bones again? This would be a good idea if the bones haven't literally disintegrated from planet earth as was reported in 2017 due to monsoon flooding. So yeah, that ends the Brachiosaurus debate. Amphicillus, specifically the species Amphicillus fragilimus, is arguably was the best example of what a gigapod is, because it was the biggest estimated dinosaur ever and easily one of the most obscure and incomplete ones as well. In fact, to add on to its dubiousness, Amphicillus isn't even Amphicillus, but I'm getting ahead of myself. Originally, the holotype of the creature, one vertebrae and possibly one femur that was never properly dug up and described, was discovered more than a century ago in 1877 by Ormel Lucas and described by the famous paleontologist Edward Drinker Cope as a member of the genus Amphicillus. This vertebrae was damaged and incomplete, yet massive, about 1.5 meters from top to bottom and completed what have been an estimated 2.7 meters. Unfortunately for us, the vertebrae went missing and was presumably destroyed after it arrived at the Natural History Museum in New York. Since Amphicillus was a diplodocid, the vertebrae was compared in scale to fellow diplodocids and the complete animal was said to have an estimated size of a whopping 58 meters. The weight was slightly less impressive, as diplodocids in general are quite light for their size, but still had an estimated weight of 120 metric tons, larger than Argentinosaurus and therefore making it the biggest dinosaur known. Now, because of the fact that we have no physical remains left of Phrygillimus and only have Lucas' and Cope's drawings to go off of, obviously Amphicillus has never been given recognition as an animal substantial enough to hold the title of biggest. Most people argue whether or not Cope made a sloppy error or even lied while documenting the size of the bone while writing his paper. After all, he was in the famous Bone Wars with his rival Othniel Marsh and was known to publish new papers as fast as possible to beat his rifle. Therefore, an error about the size could have occurred. In fact, there already is errors within the paper. For instance, he spells Phrygillimus wrong and even incorrectly abbreviates millimeters, writing 1m instead of 2. As for the reasons for if he purposely overinflated the numbers, well, Cope could probably want to look like he found a truly massive sauropod in order to outdo Marsh. These claims that Cope made an error are heavily scrutinized since his rival Marsh was eager to humiliate Cope at any misstep he made, as well as Cope was an incredibly reliable source and no one at the time questioned the measurements. However, there is another reason for not fully accepting Amphicillius' size and that's because Mr. Phrygillimus is not who we think he is. Because Amphicillius Phrygillimus isn't even Amphicillius, it's now Marapunisaurus Phrygillimus. Let me explain. In 2018, a paleontologist by the name Kenneth Carpenter re-described Amphicillius as instead of being a diplodocid, was in fact a rhabactosaurid due to the fact that vertebrae shares more in common with fellow rhabactosaurids than diplodocids. Because of this, Amphicillius Phrygillimus needed a new genus name, so Carpenter renamed it Marapunisaurus. It also means he had to recalculate the size of Marapunisaurus and rescaled it from the rhabactosaurid Lomaeosaurus and estimated it at about 30 meters and 60 metric tons, which is still huge, but remember is nearly half the size of the original estimates. So, the once mysterious case of the first gigapod has been solved. So, as you can see, the world of gigapods is an odd one. Some are fragmentary, others are controversial, a few had an identity crisis, and at least one's just a tree. But all of these do share one thing in common, they're huge, almost unimaginably huge, and truly show the magnificence of what nature can do. Even more encouraging is this is not a final list. Every year we get signs of bigger and bigger animals, like a giant sauropod footprint found on the western coast of Australia, which measured 1.75 meters long and might absolutely dwarf Argentina's source. Maybe someday you or I will find the next biggest gigapod. I would like to once more thank all the sources I used to help create this video, who I will leave links to in the description, as well as all the pictures I used to illustrate my information. Once more, big thanks to PaleoNerd01 on DeviantArt, whose wonderful art I used for this video, as well as some of the information about the creatures he illustrated that he included, which I also used to educate myself. And of course, once more, you brought to my attention the very idea of gigapods, and without that, I probably wouldn't have made this video. Of course, thank you for watching this video to the end, and see ya!