Two brothers, Liam and Jessin Fisher, were hiking in North Dakota with their father and cousin, Kaiden Madsen, during the summer of 2022.
They were looking for dinosaur fossils.
And they found one.
Liam and his father, Sam, noticed a large leg bone sticking out of the ground.
They shouted to the others to come and look.
“They came running," said Liam, who is now nine years old. "And dad asked, 'What is this?' And Jessin said, 'That's a dinosaur.'"
Two years later, experts removed the fossils from the ground and the remains of a young Tyrannosaurus rex are now at a museum in Colorado where people can see them.
The dinosaur is being called “Teen Rex” because it was not yet an adult when it died.
The Denver Museum of Nature and Science announced the find in early June. The fossil will be displayed and studied for years to come.
Jessin is now 12. When he saw the leg bone, he was sure it was a dinosaur, but he did not know what kind it was.
His father, Sam, contacted a childhood friend, Tyler Lyson, a scientist who studies dinosaurs and works at the museum in Denver. He sent a photo and Lyson started working on the permissions required to do an excavation. Last year, everyone went back to the place to start working.
At first, the group thought the bone belonged to a smaller plant-eating dinosaur. But later that day, Lyson said he and Jessin found the lower jaw and some large T. rex teeth.
“It still gives me goosebumps,” Lyson said.
"I was completely, like, speechless," said Kaiden, who is now 11.
Tyrannosaurus rex was one of the largest meat-eating dinosaurs. Scientists say it lived in what is now North America about 67 million years ago. All dinosaurs disappeared about 66 million years ago.
The scientists say the young T. rex was 13 to 15 years old. These dinosaurs are considered fully grown starting at 18 years. The “Teen Rex” was about 7.6 meters long, about two-thirds the size of an adult. One fossil, named Sue, which is displayed at the Field Museum in Chicago is 12.3 meters.
Lyson said the Denver display will not be as big as the display in Chicago because much of it is still contained in a large piece of rock. He said they have a hip bone, the skull and a number of vertebrae, which are back bones.
The fossil was found in a piece of soft stone, called sandstone. This leads the scientists to believe the dinosaur got stuck on a sandy area in the middle of a river.
Lyson said scientists are interested in finding ways that younger T. rexes were different from older ones. They were faster and had smaller heads. Because of this, the scientists think the young dinosaurs had a different diet than the older ones.
There are very few young Tyrannosaurus fossils available. A younger one is at the Burpee Museum in Rockford, Illinois.
Lyson said the new discovery should help dinosaur researchers understand another theory. A small number of scientists believe a dinosaur, called Nanotyrannus, was related to T. rex and lived at the same time.
A movie about the discovery with scientists from the Denver Museum of Nature and Science is expected to be released on June 21.
I’m Dan Friedell.
