Stegosaurus

Stegosaurus is a famous genus of herbivorous dinosaurs from the Late Jurassic period.

These four-legged animals lived between 155 and 145 million years ago. They are easily recognized by the upright, kite-shaped plates along their backs. They also had sharp spikes on their tails. Scientists study these fossils to understand how these massive creatures lived.

Stegosaurus is one of the most iconic dinosaurs in history. It remains a subject of great interest for paleontologists and the public alike.

Stegosaurus had a very specific body shape. They were heavily built quadrupeds with rounded backs. Their front limbs were short, while their hind limbs were quite long. This body structure caused them to hold their tails high in the air.

They had small heads and short necks. Because of this, they likely fed on low-lying shrubs and bushes. Their brain-to-body mass ratio was relatively low. They lived alongside other dinosaurs like Apatosaurus, Diplodocus, and Camarasaurus.

Some predators, such as Allosaurus, may have preyed on them.

The function of their unique features is still studied. Scientists generally agree that the spiked tails were for defense. These spikes helped protect them from predators. The large plates on their backs served different purposes. They were likely used for display to other dinosaurs. They may also have helped with thermoregulation. Thermoregulation is the process of managing body heat.

This allowed the animal to control its temperature through the plates.

Researchers recognize three main species in the upper Morrison Formation. These are Stegosaurus stenops, Stegosaurus ungulatus, and Stegosaurus sulcatus.

Stegosaurus ungulatus was one of the largest stegosaurians known. Some specimens measured a great length and weighed over 5,000 kilograms. Stegosaurus sulcatus is notable for a large spike. Some scientists think this was a shoulder spike used to identify the species. Fossils have been found in the western United States and in Portugal. Over 80 individual animals have been discovered so far.

The discovery of Stegosaurus happened during the "Bone Wars."

Othniel Charles Marsh first identified the remains in 1877. He worked at Dinosaur Ridge National Landmark. The first fossils were very fragmentary and scattered. Marsh originally thought the animal was an aquatic, turtle-like creature. He named it "roofed lizard" because he thought the plates overlapped like roof shingles. Later, he incorrectly assigned bones from other dinosaurs to this genus. It took many years to understand the true posture and plate arrangement.

Understanding the plate arrangement took a long time.

In 1901, Frederick Lucas suggested the plates were in paired rows. He even had an artist create a life restoration. However, scientists later debated if the plates were paired or staggered. Richard Swann Lull thought the plates shifted after the animal died. But Charles Gilmore argued that the alternating rows were natural. By 1924, the staggered pattern became the accepted standard. This changed how museums mounted the skeletons for the public.

Today, Stegosaurus is a star of natural history museums.

Because complete skeletons are rare, many museums use composite displays. A composite display uses bones from several different individuals. The National Museum of Natural History has a famous mount of S. stenops. The American Museum of Natural History also has a famous composite mount. These skeletons help us connect the biology of dinosaurs to the wider history of Earth. Stegosaurus continues to appear in films, books, and even on postal stamps.