Parasaurolophus

This dinosaur is very large.

It had a long tube on its head. This tube is a hollow crest. It may help the dinosaur make sounds.

It also used the crest to hear.

This animal ate only plants. It liked leaves and twigs.

It used a beak to pick up food. Its teeth helped it grind the plants.

It could walk in two ways. It could walk on four legs. It could also run on two legs.

Some of these dinosaurs were small. One was a young dinosaur named Joe. He was only one year old.

We find their bones in many places. They lived a long time ago. It is fun to learn about them!

Parasaurolophus was a large dinosaur that lived long ago.

Its name means "beside crested lizard." This dinosaur was a herbivore. That means it ate only plants like leaves and twigs.

It had a very special head. A large, hollow crest grew from its skull. This crest was a tube that went from its nose to the top. Scientists think the crest helped the dinosaur in many ways. It might have helped them make sounds. It might have helped them hear or stay cool.

There were three main types of this dinosaur. One type, P. walkeri, had a long crest. Another type, P. tubicen, was the largest. The third type, P. cyrtocristatus, was the smallest. It had a short and rounded crest.

These dinosaurs could move in two ways. They could walk on four legs. They could also run on two legs. Some were very young. One baby was named Joe. Joe was only one year old when he died.

Parasaurolophus was a huge dinosaur that lived a very long time ago.

It lived during the Late Cretaceous period, about 76.5 to 73 million years ago. These animals lived in what is now western North America and maybe even Asia. They were herbivores, which means they only ate plants. They used their beaks to crop leaves, twigs, and pine needles.

They could eat food from the ground up to about 1 meter high. These dinosaurs were very large and could weigh a lot. They could walk on four legs or run on two legs.

The most amazing thing about them was the crest on their heads.

This crest was a hollow tube made of bone. It grew from the nose and went up through the top of the head. In the largest species, the crest was a long, curved tube. Scientists have many ideas about why they had these crests. They might have used them to make loud sounds to talk to each other. The crests might also help them hear better or stay cool.

People first found and named this dinosaur in 1922.

A man named William Parks described it using a skull found in Alberta. He named the first species P. walkeri to honor Sir Byron Edmund Walker. Later, in 1921, Charles H. Sternberg found another partial skull in New Mexico. This led to the naming of a second species called P. tubicen. In 1961, John Ostrom described a third species named P. cyrtocristatus. Scientists are still finding new things about them today.

There are three main species that we know for sure.

The first is P. walkeri, which is the type species. The second is P. tubicen, which is the largest of them all. It had a very complex interior inside its long, straight crest. The third is P. cyrtocristatus, which is the smallest species. This one had a short, rounded crest that looked like a circle. Some scientists even think a fourth species, P. jiayinensis, might belong to this group.

You can think of their teeth like a machine for eating.

They had hundreds of teeth packed together in groups called dental batteries. As teeth wore down, new ones grew in to replace them. This helped them grind up tough plants easily. Their skin was also interesting to look at. We have found skin impressions that show they had small, bumpy scales. These scales were uniform across their bodies.

Parasaurolophus is a famous genus of hadrosaurid dinosaurs. These animals are often called "duck-billed" dinosaurs. They lived during the Late Cretaceous period. This was approximately 76.5 to 73 million years ago.

They lived in western North America. Some evidence suggests they may have lived in Asia too. These dinosaurs were large herbivores. This means they ate only plants. They were quite big and heavy.

They could move in two ways. They could walk on four legs or run on two legs.

The most striking feature of Parasaurolophus was its cranial crest. This crest is a large growth on the back of the head. It is made of the premaxilla and nasal bones. The crest was hollow inside.

Inside the crest, distinct tubes ran from the nostrils. These tubes went to the end of the crest. Then, they reversed direction and traveled back into the skull. Scientists have several ideas about why these crests existed. One idea is acoustic resonance. This means they might have used the crests to make loud sounds for communication. Other theories suggest they helped with hearing or thermoregulation. Thermoregulation is the process of controlling body temperature.

There are three universally recognized species within this genus. The first is Parasaurolophus walkeri, which is the type species.

It has a relatively simple internal crest structure. The second species is Parasaurolophus tubicen. This is the largest of the three species. It lived in New Mexico. Its crest was long and straight. It also had a very complex interior of tubes.

The third species is Parasaurolophus cyrtocristatus. This is the smallest species. It had a short, rounded crest with a circular profile. Some scientists thought it might be a female of the other species. However, most studies now disagree due to differences in crest structure and age.

History shows how much we have learned about these animals. William Parks first described the genus in 1922. He used a skull and partial skeleton found in Alberta, Canada. He named the species P. walkeri after Sir Byron Edmund Walker.

In 1921, Charles H. Sternberg found a partial skull in New Mexico. This specimen was later described as P. tubicen by Carl Wiman in 1931. The name tubicen comes from the Latin word for "trumpeter." In 1961, John Ostrom described P. cyrtocristatus. Modern technology has also helped. Robert Sullivan and Thomas Williamson used computed tomography in 1999 to study the anatomy of the genus.

Parasaurolophus had a very specialized way of eating. They used a beak to crop plant material.

They had a cheek-like organ to hold the food in their jaws. Their teeth were arranged in dental batteries. These batteries contained hundreds of teeth. The teeth were constantly being replaced as they wore down. This allowed them to grind tough plants like leaves, twigs, and pine needles. They were likely browsers. This means they fed on vegetation at different heights. They could reach plants up to about 1 meter off the ground.

We can also learn about their growth from fossils. A juvenile specimen named "Joe" was found in the Kaiparowits Formation.

Joe was only about one year old when he died. This specimen is the youngest Parasaurolophus ever found. It was about 25% of the size of an adult. This helps scientists understand how they grew. It shows that their crests began to grow much earlier than in related dinosaurs like Corythosaurus. The skeleton of a large P. walkeri could reach over 10 meters in length. Some estimates suggest they weighed more than 2,000 kilograms.

Finally, we can see how Parasaurolophus fits into the wider world of dinosaurs. They belong to the hadrosaurid family. This family includes many diverse ornithopods. These dinosaurs are known for having many strange head decorations. Parasaurolophus is part of a specific group called the lambeosaurines.

Their closest known relative is Charonosaurus from China. Some scientists believe these two might form a group called Parasaurolophini. This connection shows how these dinosaurs might have spread across different landmasses during the Cretaceous period.