Speaker 1: Welcome to brain Stuff, a production of iHeart Radio, Hey
Speaker 1: brain Stuff Lauren Vogelbaum. Here. There's ongoing debates about which
Speaker 1: dinosaur might be the largest animal to have ever RealMed
Speaker 1: the Earth. One candidate is a ninety eight million year
Speaker 1: old skeleton of a long necked titanosaur discovered in northwest
Speaker 1: Patagonia in in research published one in the journal Cretaceous Research.
Speaker 1: The authors said that they believe it could be one
Speaker 1: of the largest sauropods ever found, even larger than the
Speaker 1: one on display at the American Museum of Natural History.
Speaker 1: That's a hundred and twenty two ft long. That's thirty
Speaker 1: seven ms. But why did priest work animals like these
Speaker 1: get so big in the first place? After all, we
Speaker 1: do still have megafauna that reached towering sizes, like elephants, rhinoceros,
Speaker 1: and hippopotamus, But most of the largest land animals living
Speaker 1: today would still look like little buddies next to the
Speaker 1: literal mammoths of prehistory. And there are several hypotheses about
Speaker 1: why these creatures grew so massive. Several studies have linked
Speaker 1: environmental factors such as higher oxygen content in the air
Speaker 1: to the expansion of huge sauropod dinosaurs in North America.
Speaker 1: For example, a study published in twenty nineteen reported the
Speaker 1: researchers using a new technique to analyze tiny amounts of
Speaker 1: gas trapped inside two hundred and fifteen million year old
Speaker 1: rocks from the Colorado Plateau and the Newark Basin. Jumps
Speaker 1: in oxygen levels in layers of the rock correlate with
Speaker 1: the first dinosaurs appearing in the area and then massive sauropods.
Speaker 1: The existence of sauropods leads us to a second hypothesis
Speaker 1: about why these animals grew so gigantic efficient food uptake.
Speaker 1: The thought behind this idea is that because sarropods had
Speaker 1: such long necks, they must have been more efficient eaters
Speaker 1: than other large herbivores, meaning they could cover much larger
Speaker 1: feeding grounds and reach food that was inaccessible to other
Speaker 1: dinosaur wars. So, in theory, the massive sauropods must have
Speaker 1: been able to grow larger than other dinosaurs because they
Speaker 1: fed more efficiently. Then there's Cope's rule, which is the
Speaker 1: hypothesis formulated by paleontologist Edward Cope that says that animals
Speaker 1: in evolving lineages tend to get larger over time, and
Speaker 1: a twelve study by the Department of paleo Biology at
Speaker 1: the National Museum of Natural History found that Cope was
Speaker 1: right well some of the time. Using advanced statistical methods,
Speaker 1: the team used dinosaur femur bones to estimate animal size.
Speaker 1: They then used that data in their statistical model to
Speaker 1: look for too things, directional trends in size over time,
Speaker 1: and whether there were any detectable upper limits for body size.
Speaker 1: What they found was some groups or clades of dinosaurs,
Speaker 1: including the long necked sauropods, do grow larger over time,
Speaker 1: as Cope's rule suggests. However, others like therapods, which include
Speaker 1: the popular Tyrannosaurus rex, did not. Other evidence points to
Speaker 1: why prehistoric animals that flew grew so massive, and specifically,
Speaker 1: it points to their bones and lungs. Parasaurs, for instance,
Speaker 1: started out small, but some species ballooned to unbelievable proportions.
Speaker 1: This could have been due in part to a highly
Speaker 1: effective float through respiratory system, which allowed them the ability
Speaker 1: to sustain flight. Take one of the largest flying pterosaurs
Speaker 1: in the world as Dark Kids and I do hope
Speaker 1: on saying that right. They had wingspans of thirty three
Speaker 1: feet that's ten meters and weighed as much as four
Speaker 1: hundred and forty pounds that's two hundred kilos. Studies have
Speaker 1: shown that their bones were made up of intricate structures
Speaker 1: that made them both super strong and stable, but also
Speaker 1: super light. They may have been able to fly as
Speaker 1: far as ten thousand miles that's sixteen thousand kilometers without
Speaker 1: resting or eating, and the supersaurus is also thought to
Speaker 1: have had extraordinarily light bones and a complex system of
Speaker 1: air sacks, which could have allowed it to grow huge
Speaker 1: without collapsing in on itself. They also had very efficient lungs,
Speaker 1: so their respiration and heat exchange could better support their
Speaker 1: larger size. Of course, all of the animals we've mentioned
Speaker 1: were the top predators of their time, which made them
Speaker 1: a lot less susceptible to becoming other animals dinner. One
Speaker 1: exception to the animals being smaller these days rule are whales.
Speaker 1: For example, the blue whale makes the supersourus seem small.
Speaker 1: Blue whales grow on average to between seventy five and
Speaker 1: nine ft in length that's about twenty three to twenty
Speaker 1: seven and way about two hundred tons. Though it is
Speaker 1: difficult to measure such a huge creature underwater. Being ocean bound,
Speaker 1: they have buoyancy on their side, which makes it possible
Speaker 1: for them to weigh three times with the supersourus wave
Speaker 1: without their bodies collapsing. Today's episode is based on the
Speaker 1: article why were so many prehistoric animals So big? On
Speaker 1: how stuff works dot Com, written by Karen Kirkpatrick and
Speaker 1: Sarah glime A. Brain Stuff is production by Heart Radio
Speaker 1: in partnership with how stuff Works dot Com is produced
Speaker 1: by Tyler Clang. Four more podcasts my Heart Radio viausit,
Speaker 1: the iHeart Radio app, Apple Podcasts, or wherever you listen
Speaker 1: to your favorite shows,