This is a big dinosaur. 
This big dinosaur had a beak like a duck. 
It lived a long time ago. It lived near the coast. It ate plants to live.
This animal could walk in two ways. It could walk on two legs. It could also walk on four legs.
It lived in large groups. They may have traveled together. This helped them move to new places.
Some fossils even show its skin. Scientists can see how it looked. It is a very special find. 
Edmontosaurus was a large dinosaur. Its name means "lizard from Edmonton." 
This dinosaur had a wide beak. It looked like a duck's beak. Because of this, people called it a duck-billed dinosaur. 
There were two main types of Edmontosaurus. One lived 73 million years ago. The other lived 66 million years ago. They lived in western North America. They liked to live near the coast. 
Edmontosaurus was a herbivore. This means it ate plants. It could walk on two legs. It could also walk on four legs. These dinosaurs may have lived in large groups. They might have moved together to find food.
Scientists have found many fossils. Some fossils even show skin marks. These marks show what the skin looked like. One fossil even had parts of its last meal inside. 
Researchers can study their bones. They can even see marks from old injuries. Some fossils show attacks from a Tyrannosaurus. This helps us learn how they lived.
Edmontosaurus was a huge dinosaur from a group called hadrosaurids. Its name means "lizard from Edmonton." Many people used to call it Anatosaurus or Anatotitan. These names mean "duck lizard" or "giant duck." This is because of its wide, duck-like beak. It was one of the last non-avian dinosaurs to live. This means it lived right before a major extinction event. It lived alongside famous dinosaurs like Triceratops and Tyrannosaurus.
This dinosaur had a very interesting way of moving. It was a herbivore, so it ate only plants. It could walk on two legs to move quickly. It could also walk on four legs. Scientists think it lived in large groups. They believe these groups might have been migratory. This means they moved from place to place to find food. Many fossils were found in bone beds. These groups of bones suggest they traveled together in herds.
Finding out about Edmontosaurus took a long time. The history of its names is very complicated. Othniel Charles Marsh named a species in 1892. Back then, he called it Claosaurus annectens. Later, Lawrence Lambe named the genus Edmontosaurus in 1917. He found fossils in southern Alberta, Canada. This area is named after the city of Edmonton. For many years, scientists kept changing the names of these fossils. They used names like Trachodon and Anatosaurus for a long time.
We know a lot because of great fossil finds. One species, E. regalis, lived 73 million years ago. The other, E. annectens, lived 66 million years ago. These dinosaurs lived in western North America. Their fossils range from Colorado up to Alaska. Some were very large. An E. annectens could grow to 12 meters long. Some specimens even weighed a huge amount. These fossils were found in rocks from the Cretaceous period.
Fossils give us amazing clues about their lives. Some fossils are like mummies because they show skin impressions. 
Edmontosaurus is a genus of hadrosaurid dinosaurs. Hadrosaurids are commonly known as duck-billed dinosaurs. This name comes from their wide, duck-like beaks. Edmontosaurus was a large herbivore, meaning it ate only plants. It was a highly successful animal that lived in western North America. Its fossils have been found in areas ranging from Colorado to the northern slopes of Alaska. Scientists believe these dinosaurs preferred living near coasts and coastal plains. They were among the last non-avian dinosaurs to exist. This means they lived right up until the Cretaceous–Paleogene extinction event. During this time, they lived alongside famous dinosaurs like Triceratops and Tyrannosaurus.
This dinosaur had a specialized way of moving and living. Edmontosaurus was capable of moving on both two legs and four legs. Because many fossils have been found in bone beds, researchers believe they lived in large groups. These groups may have been migratory, traveling long distances to find food. As members of the saurolophine group, they had specific physical features. Unlike some other hadrosaurids, they lacked large, hollow crests on their heads. Instead, they possessed smaller, solid crests or fleshy combs. These features helped distinguish them from other members of their family.
There are two primary species within the Edmontosaurus genus. The first is Edmontosaurus regalis, which lived approximately 73 million years ago. Its fossils come from the late Campanian age of the Cretaceous period. The second species is Edmontosaurus annectens, which lived much later. Its fossils date to the end of the Maastrichtian age, about 66 million years ago. This species was exceptionally large. While average specimens had a specific body mass, the largest E. annectens could reach lengths of about 12 meters. These massive animals were a dominant part of their ancient ecosystems.
The history of discovering Edmontosaurus is very complex. It has been known by many different scientific names over the decades. In 1892, Othniel Charles Marsh named a species as Claosaurus annectens. Later, in 1917, Lawrence Lambe established the genus Edmontosaurus. He named it after the city of Edmonton, near where fossils were found in Alberta, Canada. For a long time, scientists used names like Anatosaurus or Anatotitan. Many of these names are now considered synonyms of Edmontosaurus. This means they actually refer to the same animal. This confusion happened because early paleontologists were still learning how to classify these diverse animals.
Many significant fossils have helped scientists understand this dinosaur. In 1908, Charles Hazelius Sternberg discovered a "mummified" specimen known as AMNH 5060. 
Fossils also reveal the daily struggles and biology of the animal. By studying bone specimens, researchers have examined the Edmontosaurus brain. They have also looked at pathologies, which are injuries or diseases found in the bones. For example, some specimens show evidence of attacks by Tyrannosaurus. One fossil even shows a damaged and partially healed tail spine. These details allow scientists to reconstruct the life and health of the animal. They provide a window into how these creatures interacted with their environment and each other.
The study of Edmontosaurus connects to many areas of science. It helps paleontologists understand the evolution of hadrosaurids and their diverse body shapes. It also provides data on the timing of the Cretaceous–Paleogene extinction event. By studying their distribution, scientists learn about ancient climates and coastal environments. The wealth of fossils makes Edmontosaurus one of the most important animals for studying dinosaur life. It serves as a key example of how large herbivores functioned in the late Cretaceous world.
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