Stegosaurus facts for kids
Quick facts for kids StegosaurusTemporal range: Upper Jurassic, 155 – 145 mya
|
|
|---|---|
 |
|
| Model Stegosaurus, Bałtów Jurassic Park, Poland. | |
| Scientific classification | |
| Kingdom: | |
| Phylum: | |
| Class: | |
| Superorder: | |
| Order: | |
| Suborder: | |
| Infraorder: | |
| Family: | |
| Genus: |
Stegosaurus
Marsh, 1877
|
Stegosaurus (meaning "roof-lizard") was a type of plant-eating dinosaur which lived in what is now western North America.
Stegosaurus lived in the Upper Jurassic period around 155 to 145 million years ago. It is one of the most easily recognized dinosaurs, with its distinctive double row of kite-shaped plates on its back, and the long spikes on its tail. The armor was necessary as it lived with such meat-eaters as Allosaurus and Ceratosaurus.
Contents
Discovery and species
Stegosaurus was originally named by Othniel Charles Marsh in 1877, from fossils found near Morrison, Colorado. These first bones became the first species of Stegosaur named: Stegosaurus armatus.
Several different Stegosaurus species have been found.
- Stegosaurus armatus: This was the first type of Stegosaurus to be found. Over thirty different skeletons have been discovered by scientists. This type had four tail spikes and small plates. At 9 meters (30 ft), it was the longest species of Stegosaurus.
- Stegosaurus stenops: Named by Marsh in 1887, it was discovered near Cañon City, Colorado, in 1886. This is the best known species of Stegosaurus, mainly because its fossils make at least one complete skeleton. It had large, broad plates and four tail spikes. S. stenops is known from at least 50 partial skeletons of both adults and juveniles, one complete skull and four partial skulls. It was shorter than S. armatus, at 7 m (23 ft).
- Stegosaurus longispinus: This type of Stegosaur is known from one incomplete skeleton. S. longispinus had a set of very long tail spines. Like S. stenops, it grew to 7 m (23 ft) in length.
- S. ungulatus: Named by Marsh in 1879 from remains recovered at Como Bluff, Wyoming, it is only known from a few backbones and armor plates. It is probably the same as S. armatus.
- S. sulcatus: This is another partial skeleton. It is probably the same as S. armatus.
- S. duplex: This animal is probably the same as S. armatus. It was also named by Marsh in 1887,. Its fossils were found in 1879 by Edward Ashley at Como Bluff, Wyoming.
- ?S. seeleyanus: Probably the same as S. armatus.
- ?S. (Diracodon) laticeps: Named by Marsh in 1881 from some jawbone fragments.
Paleobiology
Stegosaurus was the largest stegosaur, reaching up to 12 m (39.4 ft) in length and weighing up to 5,000 kg (5.5 short tons). However, 7 to 9 m was a more usual length.
Skull
The skull of Stegosaurus was long and narrow. Because of its short front legs, its head was close to the ground, probably no higher than 1 m (3.3 ft). It ate low-growing plants because of this. It had no front teeth, but it did have a horn-covered beak. Stegosaurian chewing teeth were small and triangular and did little grinding as they lacked wear surfaces.
Unlike most dinosaurs, it did not have a lacuna (hole) in its skull between the nose and eye.
Nervous system
It has often been said that the Stegosaurus brain was the size of a walnut. Actually, it had a brain several times the size of a walnut. The bundle of nerves near the base of the tail that controlled reflexes in the back of the body was larger than the brain and is sometimes said to be a "second brain". These issues are discussed in Dinosaur brains and intelligence.
Posture
Stegosaurus had very short forelimbs in relation to its hind legs. The back legs each had three short toes, while the front legs had five toes. All four limbs were supported by pads behind the toes.
Classification
Stegosaurus was a member of the Thyreophora, or armored dinosaurs, a family of dinosaurs which includes the ankylosaurs.
Cultural significance
One of the most recognizable of all dinosaurs, Stegosaurus has been depicted on film, in cartoons and comics and as children's toys. Due to the fragmentary nature of most early Stegosaurus fossil finds, it took many years before reasonably accurate restorations of this dinosaur could be produced. The earliest popular image of Stegosaurus was an engraving produced by the French science illustrator Auguste-Michel Jobin, which appeared in the November 1884 issue of Scientific American and elsewhere, and which depicted the dinosaur amid a speculative Morrison age Jurassic landscape. Jobin restored the Stegosaurus as bipedal and long-necked, with the plates arranged along the tail and the back covered in spikes. This covering of spikes might have been based on a misinterpretation of the teeth, which Marsh had noted were oddly shaped, cylindrical, and found scattered, such that he thought they might turn out to be small dermal spines.
Marsh published his more accurate skeletal reconstruction of Stegosaurus in 1891, and within a decade Stegosaurus had become among the most-illustrated types of dinosaur. Artist Charles R. Knight published his first illustration of Stegosaurus ungulatus based on Marsh's skeletal reconstruction in a November 1897 issue of The Century Magazine. This illustration would later go on to form the basis of the stop-motion puppet used in the 1933 film King Kong. Like Marsh's reconstruction, Knight's first restoration had a single row of large plates, though he next used a double row for his more well-known 1901 painting, produced under the direction of Frederic Lucas. Again under Lucas, Knight revised his version of Stegosaurus again two years later, producing a model with a staggered double row of plates. Knight would go on to paint a stegosaur with a staggered double plate row in 1927 for the Field Museum of Natural History, and was followed by Rudolph F. Zallinger, who painted Stegosaurus this way in his "Age of Reptiles" mural at the Peabody Museum in 1947.
Stegosaurus made its major public debut as a paper mache model commissioned by the U.S. National Museum of Natural History for the 1904 Louisiana Purchase Exposition. The model was based on Knight's latest miniature with the double row of staggered plates, and was exhibited in the United States Government Building at the exposition in St. Louis before being relocated to Portland, Oregon for the Lewis and Clark Centennial Exposition in 1905. The model was moved to the Smithsonian National Museum of Natural History (now the Arts and Industries Building) in Washington, D.C. along with other prehistory displays, and to the current National Museum of Natural History building in 1911. Following renovations to the museum in the 2010s, the model was moved once again for display at the Museum of the Earth in Ithaca, New York.
On July 17, 2024, a large Stegosaurus skeleton, "Apex", fetched $44.6m (£34m) at a Sotheby's auction in New York City - the most ever paid for a fossil.
Images for kids
-
Marsh's 1891 illustration of S. ungulatus. Note the single row of 12 large rounded plates, based on those of S. stenops, and eight spikes
-
Type specimen of S. stenops on display at the National Museum of Natural History.
-
S. stenops skull cast, Natural History Museum of Utah
-
Life restoration of S. stenops based on the "Sophie" specimen
-
Restoration of S. stenops with alternating plate arrangement.
-
Adult and juvenile S. stenops mounted as if under attack from an Allosaurus fragilis, Denver Museum of Nature and Science
-
Back plate cast, Museum of the Rockies
-
Plates of Stegosaurus specimen "Sophie"
-
Thagomizer on mounted tail
-
Punctured Allosaurus tail vertebra by a Stegosaurus thagomizer, the damage shows that the spike entered at an angle from below and displaced a piece of the process upward, remodeled bone on the underside of the process shows that an infection developed
-
Brain cavity of S. stenops marked with red
-
Footprints of an adult and juvenile from the Morrison Formation
-
The first mounted skeleton of a stegosaur (S. ungulatus), Peabody Museum of Natural History, 1910
.jpg)
_(15354473407).jpg)
See also
In Spanish: Stegosaurus para niños
