Hobbies And Interests
Time Period
Triceratops, or "three-horned face," was an herbivore that lived toward the end of the Cretaceous period, between 72 and 65 million years ago. The stegosaurus, or "roofed lizard," was an herbivore that lived between 80 and 90 million years earlier than triceratops, during the late Jurassic period 161 to 146 million years ago.
Appearance
Triceratops was a cerotopsian, or horned dinosaur. Triceratops was about 10 feet tall, 30 feet long and weighed between four and six tons. Its head was between four- and five-feet wide, with two horns above the eyes and one above the mouth. The back of the head featured a bony frill six feet wide. The largest armored dinosaur, stegosaurus, was about 26 to 30 feet long, stood about nine feet tall and weighed more than three tons. Stegosaurus' tiny head contained a brain about the size of a walnut. Stegosaurus' front legs were shorter than its hind legs, giving it a low head and a rounded back. Its back featured 17 bony plates in two rows and its tail ended in a set of spikes named a thagomizer after a stegosaurus joke from Gary Larson's "Far Side" comic.
Iconic Features
Paleontologists believe triceratops used its horns in mating rituals and as protection from predators such as tyrannosaurus rex. Paleontologists have suggested several purposes for the frill, such as attracting mates like a peacock's colorful tail, protection from predators and regulating the animal's body temperature by radiating heat. The exact purpose of the stegosaurus' plates is also unknown. According to the website Science Views, stegosaurus may have used them as as defense against predators by folding them to one side or the other, although this wouldn't have protected them from a predator such as the Allosaurus. Other theories suggest that stegosaurus used them as a display or warning by flushing them with blood or for controlling its temperature by directing them into the sun or wind as needed. Paleontologists believe stegosaurus used its thagomizer as a defense against predators.
Triceratops Discovery
In 2010, American paleontologists John Scannella and Jack Horner revealed evidence that the triceratops may have actually been the juvenile form of torosaurus. Both had three horns and a frill. However, the torosaurus' horns were at different angles on its head than triceratops' horns and its frill was thinner. After comparing their skulls, Scannella and Horner concluded that the triceratops' spongy horns and frill gradually changed shape and hardened as it aged. They also discovered that frills on the oldest triceratops' skulls showed signs of thinning and the development of holes associated with torosaurus frills. According to Scanella and Horner, the frill was probably used as a display of age rather than as a defense.