How Did Stegosaurus Work?

built carnivore. The case of Stegosaurus isn't so straightforward. Rooted in Greek, this Jurassic plant gobbler's name means roofed lizard, which made a lot more sense when the animal was first discovered over a hundred and forty years ago. But let's back up a little. A Stegosaurus belonged to a suborder of dinosaurs called what else the stegosaurs found in North America, Europe, Asia, and mainland Africa. The stegosaurs walked on four legs and had long, beak tipped skulls, but

it's the ornaments that really grab your attention. The spikes were a stegosaur mainstay, adorning the tails of every known species. Many of these creatures like Africa's Kentrosaurus also rocked big old spikes on the shoulders and lower back, and where the back spikes came to an end, a much weirder feature took over. A Stegosaurus and its kin are characterized by the vertical plates above their spines. The paleontologist Othniol

Charles Marsh named Stegosaurus in eighteen seventy seven. He chose this name, which again means roofed lizard, because he figured the plates were sheets of armor that laid flat against the animal's backside. Instead, later discoveries proved the objects stood upright, leaving the flanks on these dinosaurs exposed. We may never know how these things functioned. Because the plates contained blood vessels, experts used to think that they helped Stegosaurus chill out.

The heat would supposedly dissipate from blood as it entered the tall fan like structures. When the chilled blood circulated elsewhere, it would stay cool for a little while lowering the overall body temperature. This hypothesis is no longer popular. According to a study published in two thousand five in the journal Paleobiology, The blood carrying networks and Stegosaurus. As plates were there to promote healthy bone growth, but they played

no role in dissipating body heat. Or maybe Stegosaurus and its kin were just showing off a made of bone and encased in horny sheats. The plates could have made these dinos look bigger than more intimidating. Capable of hitting over twenty nine feet that's nine meters in length and weighing about five tons or four and a half metric tons,

a stegosaurus would loom large over today's land mammals. Even by stegosaur standards, it was a biggie, and most of the dinosaurs in that group were only thirteen to twenty three feet long that's about four to seven ms. Yet in the late Jurassic, when these species lived, the Stegosaurus

was in the shadows of behemoths. Sauropods, or long necked dinosaurs like the sixty foot or eighteen meter Kmarasaurus and the eighty foot or twenty four meter Diplodocus were some of the creatures neighbors, but the Tyrannosaurus rex wasn't, and despite movies like Fantasia and The Camp Classic Planet of Dinosaurs showing Stegosaurus duking it out with the t Rex. Those two dinos never crossed paths in real life. Tyrannosaurus had a fairly short rain that lasted from sixty eight

to sixty five and a half million years ago. The Stegosaurus came and went much much earlier. The oldest specimens on record are around a hundred and fifty five million years of age, while the youngest were fossilized hundred and fifty billion years before the present, So the mighty t Rex actually lived closer to the dawn of mankind than

it did to the Stegosaurus is heyday. The Jurassic Period, which lasted from a hundred and ninety nine point six million to a hundred and forty five point five million years ago, was drawing to a close when Stegosaurus roamed the earth. Although its range included modern day Portugal, the beast is mainly known from fossil sites in western North America, and while Stegosaurus didn't have to worry about t Rex,

a rogues gallery of Jurassic predators stalked its ecosystem. Allosaurus was especially common, measuring up to twenty eight feet that's eight and a half meters long. This carnivore had serrated teeth and jaws that could open wide at a terrifying seventy nine degree angle. Good things. Diegosaurus had four tail spikes at its disposal. We know they saw action once

in a while too. A study published in two thousand one in the Armored Dinosaurs by the Indiana University Press found clear evidence of trauma on ten percent of the fifty one tail spikes that they studied, and apparently the roofed lizard hit below the belt. One Allosaurus pubic bone shows a deep wound thought to have been made by a Stegosaurus tailspike. The stegosaurus had another line of defense. The underside of its throat was covered in tiny pebble

shaped chunks of bone called Ghouler armor. It helped protect the dinosaur when Allosaurus and other carnivores went for the jugular Paleontologists think Stegosaurus browsed on low lying vegetation. A computer simulation found that the animals bite force would have rivaled that of a sheep or cow, but however, it processed its food. This dinosaur didn't need much gray matter. A Stegosaurus had a brain cavity that was long narrow and tiny, tipping the scales at twenty ounces, that's eighty

grams or so. The actual brain only made up about zero point zero zero one percent of the creature's total body weight. And note that we said brain, not brains. As absurd as it might sound, there was a rumor that Stegosaurus had a second brain located where the sun don't shine. Writing in one Marsh drew attention to the enlarged cavity that we find in the backbones above this dinosaurs hip region. Then he went and called it a

posterior brain case. No one knows for sure what this opening was for, though some researchers think it stored glycogen, sugar that provides cells with energy. Regardless, there is no reason to think that Steatosaurus or any dinosaur had multiple brains. The Stegosaurus did have some pretty cool bragging rights though. Not only is the Jurassic her Before Colorado's official state fossil, but it was also the inspiration for Godzilla's dorsal plates,

as we have discussed on the show before. Today's episode is based on the article Stegosaurus body like a bus, tiny little brain on how Stuff Works dot com, written by Mark Mancini Breen Stuff is production of by heart Radio in partnership with how stuff works dot Com and is produced by Tyler Klang. Four more podcasts from my heart Radio. Visit the iHeart Radio app, Apple Podcasts, or wherever you listen to your favorite shows.