Stegosaurus is a crowd-pleaser. Slow enough to admire, sufficiently irascable to add an element of danger to your trip, this beast is sure to offer an experience you won’t forget.
Time & Place
Your Guide will take you 155 million years into the past[1], arriving safely in the late-Jurassic version what is now the western United States or Portugal[8]. (Precise destination will be booked by availability.)
The Roof Lizard
Othniel Charles Marsh first described Stegosaurus in 1877, dubbing it “roof lizard” because he believed the large bony plates he’d found fitted on the back of a giant turtle, forming the protective roof-like shell we see in turtles, tortoises, and terrapins[1].
Later discoveries informed scientists of Stegosaurus‘s true morphology: that of a tall-backed creature, with a low-slung head and disproportionately long hindlimbs, twin rows of alternating plates erected along the back, and two pairs of impaling spikes projecting laterally from the end of the tail. Deep Time Adventures’ sister corporation, Deep Time Researches, confirms this restoration.
Despite the comically stocky forelimbs, the hips are taller than room-high[4], and the tail extends straight back, suspended by an efficient system of ligaments[5], held well off the ground at optimal height for human decapitation[1].
NOTE: Stegosaurus is a Safety Level III organism. Please reference the Safety Level fact sheet for more information.
Stegosaurus‘s long tail and dancer’s legs allow it to rear up, the tail acting as the third leg of a tripod[3][6]. This stance furnishes the animal with greater browsing flexibility, and reports from the field suggest Stegosaurus may be able to walk slowly on two legs[3].
At up to 9 m (30 ft.) long[2] and 3.5 metric tones (3.85 US tons)[3], Stegosaurus is not to be trifled with. It is exactly its impressive size, though, that threatens to sell Stegosaurus short—with a brain the size of a kitten’s[2], it’s hard not to think of this dinosaur as monumentally stupid. But take heart: because there’s no straightforward correlation between intelligence and brain-to-body size ratio[7], we needn’t pin Stegosaurus as the Most Dimwitted Animal of All Time. Deep Time Researches has yet to study Stegosaurus intelligence, so for now, the jury’s out.
Though it was the largest stegosaurian—plated dinosaur—Stegosaurus doesn’t attain its top-of-the-class bulk and ornate display overnight. Bone growth analysis indicates this stegosaurian grows more slowly and maintains a lower metabolic rate than other dinosaurs its size[9]. But once it reaches sexual maturity, Stegosaurus‘s osteoderms (plates and spines) grow more quickly than its skeleton, meaning that an old, seasoned stegosaur boasts a fine plate display of plates and spikes divulging its years of experience[7].
Species of Stegosaurus
American paleontologist Peter M. Galton recognizes four species of the genus Stegosaurus[10].
S. stenops
S. ungulatus
S. longispinus
S. sulcatus
Distinguishing Characteristics
The iconic array of large plates protruding from its back renders Stegosaurus instantly recognizable. Size, shape, and coloration vary by species, sex, age, individual, and mood:
- The largest, most impressive plates belong to S. stenops[1].
- When feeling threatened or attracting mates (males only), stegosaurs will turn broadside toward their target and pump blood to flush their plate displays with color[1].
CAUTION: Please maintain Safety Distance II if you notice this type of display.
As you will see, the plates displayed in museum exhibits of Stegosaurus are only the bony cores of the full structure. In life, the plates are covered in keratin sheaths that lengthen them by twenty to thirty percent.
Ossicles—little disks of bone-armor—are clustered thickly along the stegosaur’s throat, extending to the top of the head and along the flanks. These patches of armor, together with the incredibly thick—10cm in some spots—dorsal skin, helping to anchor the plates, comprise Stegosaurus‘s secondary defenses [1].
Stegosaurus‘s primary defense, of course, is its thagomizer—the two pairs of spikes projecting laterally from the end of the tail. Again, familiarity with museum specimens might leave you surprised at the horrifying length and sharpness of these spikes in life. Lucky travelers, maintaing Safety Distance II, may see this weapon in action. Though eyewitness accounts are sparse, Allosaurus and Stegosaurus fossils attest to its frequent usage.
Stegosaurs travel in herds composed of variably aged individuals, easily located by searching for clouds of dust rising in the distance.
Ecology
Stegosaurus wanders the flat floodplains of its semiarid environment, weathering the wet and dry seasons as they come. Rivers snake their ways through the terrain, lined with gallery forests of conifers, tree ferns, and ferns, which transition to fern savannas dotted with occasional trees such as Brachyphyllum.
Travelers should keep watch for Stegosaurus‘s known predators: Allosaurus and Ceratosaurus. Sauropods—such as Brachiosaurus, Apatosaurus, Dipolodocus, Camarasaurus, and Barosaurus—dominate the landscape, consuming vegetation at various altitudes above the stegosaurs’ customary browsing level.
Sources
- Dinosaurs: The Grand Tour
- Dinosaurs Rediscovered
- The Princeton Field Guide to Dinosaurs
- The Ultimate Dinosaur Book
- Carpenter 1998
- Maidment 2014
- Cobb
- Escaso 2006
- Redelstorff 2009
- Galton 2010 “Species of plated dinosaur Stegosaurus (Morrison Formation, Late Jurassic) of western USA: new types species designation needed”
- “Armor of Stegosaurus stenops, and the Taphonomic History of a New Specimen from Garden Park, Colorado.”