Colorado State Fossil
Stegosaurus (common name) Stegosaurus stenops (scientific name) STATUS Official  DESCRIPTION Stegosaurus is a genus of herbivorous dinosaur that lived about 145 to 150 million years ago in the late Jurassic period of the Mesozoic era. Stegosaurus lived in what is now the western United States, specifically the states of Utah, Wyoming, Montana, Oklahoma, and Colorado. In 2007, a stegosaurus fossil was found in Portugal, supporting the widely accepted Pangaea theory. According to this theory, the present-day continents were once joined as a supercontinent that began separating at the end of the Jurassic period. Before the 2007 discovery, Stegosaurus was thought to have lived only in North America. STATE SYMBOL Stegosaurus stenops fossils are plentiful in the Morrison Formation, an area that is now Colorado, Wyoming, and Utah. A skeleton discovered by a teacher and students from Cañon City High School in Colorado is on display at the Denver Museum of Science and Nature. Several other museums and interpretive centers throughout Colorado make dinosaur fossils, tracks, and information available to the public. One example is Dinosaur National Monument, located on the Colorado/Utah border, which contains lands dinosaurs once roamed. Another is Florissant Fossil Beds National Monument in central Colorado, which contains fossils and petrified wood; it is one of the richest and most diverse fossil deposits in the world. Proposed by a Colorado fourth-grade class, Stegosaurus stenops was designated the official state fossil on April 28, 1982. NAME ORIGIN The name Stegosaurus is derived from the Greek στέγος(stegos-),meaning "roof," and σαũρος (sauros), meaning "lizard." Stenopsmeans "narrow-faced." BIOLOGY/ANATOMY Stegosaurus was a large, heavy quadruped that measured about 14 feet (4 m) tall and 30 feet (9 m) long. It weighed about 5 to 10 tons (4.5 to 9 metric tonnes). This dinosaur is recognizable for its long tail spikes and the diamond-shaped plates it carried on its arched back. Seventeen large, flat plates were arranged in rows of two and stood vertically. Originally thought to be a defense mechanism from its larger contemporaries, the spikes and plates may more likely have been used to regulate temperature, similar to the way a modern elephant’s ears do. Stegosaurus’ hind legs are longer than its front legs, which resulted in its tail being held several feet off the ground and its small head hanging down toward the ground. Small back teeth and a beak in place of front teeth suggest that stegosaurus ate low-lying vegetation by grinding it. In the Jurassic period when stegosaurus lived, the Rocky Mountains had not yet formed, and its habitat consisted of lowland plains. This dinosaur had a brain the size of a walnut. Stegosaurus is famous for its "second brain," which is actually an enlarged nerve plexus situated in the spinal cord. EVOLUTION/EXTINCTION It is not known exactly what led to the extinction of dinosaurs. The popular theory in which a giant asteroid hit the earth 65 million years ago and changed the climate would not apply to Stegosaurus stenops, as it had already died off by then. Disease or gradual climate change are possibilities. MODERN DISCOVERY The famous American paleontologist Othniel Charles Marsh namedStegosaurus stenops in 1887 from remains found north of what is now Cañon City, Colorado. TRIVIA A stegosaurus appears in The Lost World: Jurassic Park and inJurassic Park III. Despite what is shown in movies and on television, no stegosaurus ever saw a tyrannosaurus. For example, in the 1940 animated film Fantasia, a battle takes place between a stegosaurus and a Tyrannosaurus rex. The remake of the TV series Land of the Lost (1992-93) also shows a stegosaurus and tyrannosaurus. A baby stegosaurus named Spike is a lead character in the 1988 movie The Land Before Time,which also features a tyrannosaurus. However, tyrannosaurus wasn’t alive until approximately 80 million years after the extinction of stegosaurus.
	Click to enlarge an image Life-sized Stegosaurus  Artist's Rendering of Stegosaurus Wooden Skeleton Model CLASSIFICATION Kingdom: Animalia Phylum: Chordata Class: Reptilia Superorder: Dinosauria Order: Ornithischia Suborder: Thyreophora Infraorder: Stegosauria Family: Stegosauridae Genus: Stegosaurus Species: S. stenops
	Author: World Trade Press