Following the first-discovered trail of adult T.rex footprints

Scientists have discovered what they believe is the first-discovered trail of footprints left by an adult Tyrannosaurus rex.

Footprints of younger creatures have been found, but experts think these were made by a fully grown adult T.rex.

The trail, found in the US state of North Dakota, is made up of four huge three-toed footprints.

The prints are about one metre long, and researchers think the dinosaur was walking at around 4mph - that's around the speed of a quick human walk.

Experts say the discovery provides a rare opportunity to find out more about how one of the world's most famous dinosaurs moved.

The footprints were found on land managed by the US Forest Service in the American state of North Dakota.

An international team of scientists made the discovery, including researchers from the Denver Museum of Nature & Science in the US and Liverpool John Moores University in the UK.

The researchers used high-resolution 3D scanning to record each footprint.

The four footprints show two left feet and two right feet, with a massive four metres between each step.

Each footprint measures around one metre in length, and they are thought to have been made around 66.5 million years ago.

Researchers believe an adult T. rex was the most likely animal to have made them because of their huge size and narrow, three-toed shape.

The team added that they also believe it's the first time that scientists have come across a sequence of tracks - called a trackway - likely left by this famous dinosaur.

Tyler Lyson, from the Denver Museum of Nature & Science explained: "Bones tell us an enormous amount about these animals, but footprints capture a moment of behaviour.

"With a trackway, we can actually follow an animal as it moved across the landscape. That is incredibly rare for T. rex."

Three of the footprints are expected to be moved to a museum in the US city of Denver this autumn, where scientists will study them more closely.

The footprints are due to be dig out and lifted by helicopter from the site in October.

Experts say they plan to share more updates as the recovery happens.