Speaker 1: Welcome to brain Stuff, a production of iHeart Radio. Hey
Speaker 1: They're brain Stuff, Lauren Vogelbaum Here. They lived about thirty
Speaker 1: million years apart and never set foot on the same continent.
Speaker 1: Yet Giganetosaurus carolini i is always getting compared to the
Speaker 1: world's most popular dinosaur, the beloved and well known Torannosaurus rex.
Speaker 1: Toranosaurus rex has been a media darling since arguably nineteen
Speaker 1: o six, when The New York Times called it the
Speaker 1: prize fighter of antiquity. Named just one year prior, this
Speaker 1: big beast was already making a splash over at the
Speaker 1: American Museum of Natural History in Manhattan. Today, we know
Speaker 1: that an adult t Rex could stand twelve feet or
Speaker 1: about three and a half meters tall at the hip
Speaker 1: and measure forty feet or twelve meters long. As such,
Speaker 1: Torannosaurus was one of the largest predators to ever walk
Speaker 1: the earth, But hold your horses. A handful of other
Speaker 1: meat eating dinos rivaled or possibly exceeded these creatures in size.
Speaker 1: Jiganosaurus belongs to this elite group, and it's part of
Speaker 1: a dinosauran mystery that's never been solved. T Rex and
Speaker 1: Jagonatosaurus were both representatives of the Therapoda clade, a clade
Speaker 1: being a group of organisms that includes a common ancestor
Speaker 1: species and all of its presumed descendants, hollow, boned and bipedal.
Speaker 1: The therapods were and are a highly successful bunch. On
Speaker 1: the list of documented therapods, you'll find every carnivorous dinosaur
Speaker 1: ever discovered, quite a few plant gobbling species, and all
Speaker 1: birds living and extinct. The last non avian dinosaurs were
Speaker 1: wiped out at the close of the Cretaceous Period, an
Speaker 1: expanse of geologic time that lasted from a hundred forty
Speaker 1: five to sixty six million years ago. Its conclusion marked
Speaker 1: the end of the Mesozoic era, sometimes called the Age
Speaker 1: of the Dinosaurs. Tyrannosaurus rex lived in North America during
Speaker 1: the Twilight of the Cretaceous, making its evolutionary debut around
Speaker 1: sixty eight million years before the present. Our buddy, Gigonatosaurus
Speaker 1: was the product of another time and a whole different
Speaker 1: land mass. Native to western Argentina, it came along much
Speaker 1: earlier in the Cretaceous, roughly ninety seven million years ago.
Speaker 1: South America was a realm of giants. Back then, huge
Speaker 1: sauropods or long necked dinosaurs roamed the countryside, with some
Speaker 1: species stretching around fifty feet or fifteen meters long. Rounding
Speaker 1: out the local beasti area were crocodilians, early snakes, and
Speaker 1: beaked herbivores. No doubt Gigonatosaurus kept its neighbors on guard.
Speaker 1: That therapods discovery was first announced in by paleontologists rudolful
Speaker 1: Choria and Leonardo Salgado. In all the years since, we
Speaker 1: have yet to find a complete skeleton. However, the backbones
Speaker 1: and tail vertebrate at art disposal suggest Gigonatosaurus was at
Speaker 1: least forty one ft or twelve and a half meters
Speaker 1: in length, so Gigonatosaurus might have been slightly longer than Tyrannosaurus.
Speaker 1: On the other hand, a paper published in argued that
Speaker 1: t Rex had a much heavier build. Using the circumference
Speaker 1: of its upper leg bone, Roger Benson and his colleagues
Speaker 1: calculated that a mature Giganetosaurus weighed about thirteen thousand, five
Speaker 1: hundred pounds or about six thousand, one hundred kilos. The
Speaker 1: same technique put t Rex at a whopping seventeen thousand
Speaker 1: pounds or seven thousand, seven hundred kilos weight gaps are
Speaker 1: all well and good, but the jaws tell better stories.
Speaker 1: Anatomical evidence suggests that these two carnivores used very different
Speaker 1: methods to bring down their prey. The teeth of Tyrannosaurus
Speaker 1: were thick and sort of banana shaped and would have
Speaker 1: excelled a crushing bone. In contrast, Giganetosaurus had tall, skinny
Speaker 1: teeth that looked an awful lot like recurved kitchen knives
Speaker 1: serrated on both sides. These pearly whites were housed inside
Speaker 1: a narrow snout. By the way, Giganetosaurus had a monstrous skull,
Speaker 1: soient estimate this noggin was around six ft or two
Speaker 1: meters long. Combine all of these features and you're looking
Speaker 1: at a therapod that probably killed by slicing ribbons of
Speaker 1: meat off of its unfortunate prey, as opposed to shattering bones.
Speaker 1: Once bitten, a victim may have bled out while the
Speaker 1: carnivore lurked nearby. Giganetosaurus hails from one of the fossil
Speaker 1: records most intimidating families, the Cacara Donta swords. If you're
Speaker 1: into sharks, that name should ring a bell. Scientists called
Speaker 1: the Great white the car cardon Cacarius. Likewise, the word
Speaker 1: cocardonto sword roughly means shark toothed lizard in Greek. Well
Speaker 1: we spoke by email with Steve Brusatti, a paleontologist at
Speaker 1: the University of Edinburgh who studied these remarkable therapods and
Speaker 1: happens to be a scientific advisor for the next Jurassic
Speaker 1: World movie. He said, the roster of Cacara donta sword
Speaker 1: fossils has expanded tremendously over the last decade as people
Speaker 1: have found new fossils all over the world, particularly in
Speaker 1: South americ in Africa, but also in Asia and Europe.
Speaker 1: Most kacar dontosaurids, like Giganotosaurus were giant meat eating dinosaurs
Speaker 1: with deep jaws and sharp, thin, almost shark like teeth.
Speaker 1: They were the largest and most formidable predators in many
Speaker 1: ecosystems during the early to middle part of the Cretaceous
Speaker 1: before the rise of Tyrannosaurus. Indeed, t Rex itself had
Speaker 1: some puny forebears. The first members of its lineage were
Speaker 1: human sized predators that showed up around a hundred and
Speaker 1: seventy million years ago. Giant Tyrannosaurus wouldn't start evolving until
Speaker 1: the late Cretaceous period, after the mighty cocar Donta saurids
Speaker 1: died out. Brussadi said that this changeover remains a mystery.
Speaker 1: We really don't know why it happened, and it's one
Speaker 1: of the biggest remaining mysteries of dinosaur evolution in my opinion.
Speaker 1: Today's episode was written by Mark Mancini and produced by
Speaker 1: Tyler Klang. For more on this and lots of other
Speaker 1: thunderous topics, visit has to Forks dot com. Rain Stuff
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