Welcome to brain Stuff, a production of iHeart Radio, Hey brain Stuff Lauren Vogelbaum. Here. There's ongoing debates about which dinosaur might be the largest animal to have ever RealMed the Earth. One candidate is a ninety eight million year old skeleton of a long necked titanosaur discovered in northwest Patagonia in in research published one in the journal Cretaceous Research.
The authors said that they believe it could be one of the largest sauropods ever found, even larger than the one on display at the American Museum of Natural History. That's a hundred and twenty two ft long. That's thirty seven ms. But why did priest work animals like these
get so big in the first place? After all, we do still have megafauna that reached towering sizes, like elephants, rhinoceros, and hippopotamus, But most of the largest land animals living today would still look like little buddies next to the literal mammoths of prehistory. And there are several hypotheses about
why these creatures grew so massive. Several studies have linked environmental factors such as higher oxygen content in the air to the expansion of huge sauropod dinosaurs in North America. For example, a study published in twenty nineteen reported the researchers using a new technique to analyze tiny amounts of gas trapped inside two hundred and fifteen million year old
rocks from the Colorado Plateau and the Newark Basin. Jumps in oxygen levels in layers of the rock correlate with the first dinosaurs appearing in the area and then massive sauropods. The existence of sauropods leads us to a second hypothesis about why these animals grew so gigantic efficient food uptake.
The thought behind this idea is that because sarropods had such long necks, they must have been more efficient eaters than other large herbivores, meaning they could cover much larger feeding grounds and reach food that was inaccessible to other dinosaur wars. So, in theory, the massive sauropods must have been able to grow larger than other dinosaurs because they
fed more efficiently. Then there's Cope's rule, which is the hypothesis formulated by paleontologist Edward Cope that says that animals in evolving lineages tend to get larger over time, and a twelve study by the Department of paleo Biology at the National Museum of Natural History found that Cope was right well some of the time. Using advanced statistical methods, the team used dinosaur femur bones to estimate animal size.
They then used that data in their statistical model to look for too things, directional trends in size over time, and whether there were any detectable upper limits for body size. What they found was some groups or clades of dinosaurs, including the long necked sauropods, do grow larger over time, as Cope's rule suggests. However, others like therapods, which include
the popular Tyrannosaurus rex, did not. Other evidence points to why prehistoric animals that flew grew so massive, and specifically, it points to their bones and lungs. Parasaurs, for instance, started out small, but some species ballooned to unbelievable proportions. This could have been due in part to a highly effective float through respiratory system, which allowed them the ability to sustain flight. Take one of the largest flying pterosaurs in the world as Dark Kids and I do hope
on saying that right. They had wingspans of thirty three feet that's ten meters and weighed as much as four hundred and forty pounds that's two hundred kilos. Studies have shown that their bones were made up of intricate structures that made them both super strong and stable, but also
super light. They may have been able to fly as far as ten thousand miles that's sixteen thousand kilometers without resting or eating, and the supersaurus is also thought to have had extraordinarily light bones and a complex system of air sacks, which could have allowed it to grow huge without collapsing in on itself. They also had very efficient lungs, so their respiration and heat exchange could better support their
larger size. Of course, all of the animals we've mentioned were the top predators of their time, which made them a lot less susceptible to becoming other animals dinner. One exception to the animals being smaller these days rule are whales. For example, the blue whale makes the supersourus seem small. Blue whales grow on average to between seventy five and nine ft in length that's about twenty three to twenty seven and way about two hundred tons. Though it is
difficult to measure such a huge creature underwater. Being ocean bound, they have buoyancy on their side, which makes it possible for them to weigh three times with the supersourus wave without their bodies collapsing. Today's episode is based on the article why were so many prehistoric animals So big? On how stuff works dot Com, written by Karen Kirkpatrick and Sarah glime A. Brain Stuff is production by Heart Radio in partnership with how stuff Works dot Com is produced
by Tyler Clang. Four more podcasts my Heart Radio viausit, the iHeart Radio app, Apple Podcasts, or wherever you listen to your favorite shows,