Ultrasaurus facts for kids

Ultrasaurus is the name given to a very large dinosaur that lived a long, long time ago, during the Lower Cretaceous period. This period was about 145 to 100 million years ago! Ultrasaurus was a type of sauropod, which means it was a giant, plant-eating dinosaur with a long neck and tail, like the famous Brachiosaurus or Diplodocus. However, scientists don't know much about Ultrasaurus because they've only found a few bones. This makes its name a bit of a mystery!

What is Ultrasaurus?

Ultrasaurus was first named in 1983 by a scientist named Haang Mook Kim. It was thought to be a huge sauropod dinosaur. Sauropods were the largest animals to ever walk on land. They had long necks to reach high leaves and long tails for balance.

A Mysterious Dinosaur Name

The name Ultrasaurus is considered a nomen dubium. This is a Latin term that means "doubtful name." Scientists use this term when they don't have enough fossil evidence to be sure about a dinosaur. It means they can't really tell if it's a new kind of dinosaur or just a part of one already known.

What Fossils Were Found?

Only a few bones of Ultrasaurus have ever been found. These include part of an upper forearm bone, called a humerus. They also found some back bones, which are called vertebrae. These few bones are all scientists have to try and understand this giant creature.

Why is it a "Doubtful Name"?

Because so few bones were found, it's hard for scientists to know exactly what Ultrasaurus looked like. It's also difficult to place it into a specific family of sauropods. It might even be that these bones belong to a dinosaur that already has a name. If that's true, then Ultrasaurus would become a "junior synonym." This means it's a newer name for something that already has an older, more correct name.