In July 2022, two young brothers and their cousin were wandering through a fossil-rich stretch of the North Dakota badlands when they made a discovery that left them “completely speechless”: a T. rex bone poking out of the ground.
The trio announced their find publicly on Monday (3 June) as workers at the Denver Museum of Nature & Science prepared to extract the fossil from its rock encasement at a special exhibit titled "Discovering Teen Rex."
A documentary crew with Giant Screen Films was there to capture the discovery. The film, titled "T.REX", will debut at the exhibit's opening on 21 June.
“It was electric. You got goosebumps,” recalled Dave Clark, who was part of the crew filming the documentary that later was narrated by Jurassic Park actor Sir Sam Neill.
The adventure began when Kaiden Madsen, then 9, joined his cousins, Liam and Jessin Fisher, then 7 and 10, on a hike through land owned by the Bureau of Land Management near Marmarth, North Dakota.
“You just never know what you are going to find out there. You see all kinds of cool rocks and plants and wildlife," says the brothers' father, Sam Fisher.
Liam Fisher recalled that he and his dad, who accompanied the trio, first spotted the bone of the young carnivore.
After its death around 67 million years ago, the T. rex had been buried in the Hell Creek Formation, a renowned paleontological site spanning Montana, Wyoming, and the Dakotas. This formation has yielded some of the best-preserved T. rex fossils, including Sue, a star at the Field Museum in Chicago, and Wyrex, a popular attraction at the Houston Museum of Natural Science.
But none of them knew that then. Liam said he thought the bone sticking out of the rock was something he described as “chunk-osaurus” - a made-up name for fragments of fossil too small to be identifiable.
Verifying the find
Sam Fisher snapped a picture and shared it with a family friend, Tyler Lyson, the associate curator of vertebrate paleontology at the Denver Museum of Nature & Science.
Initially, Lyson suspected it was a relatively common duckbill dinosaur. But he organised an excavation that began last summer, adding the boys and a sister, Emalynn Fisher, now 14, to the team.
It didn't take long to determine they had found something more special. Lyson recalled that he started digging with Jessin where he thought he might find a neck bone.
“Instead of finding a cervical vertebrae, we found the lower jaw with several teeth sticking out of it,” Lyson said. “And it doesn’t get any more diagnostic than that, seeing these giant tyrannosaurus teeth starring back at you.”
Based on the size of the tibia, experts estimate the dino was 13 to 15 years old when it died and likely weighed around 3,500 pounds (1,587.57 kilograms) - about two-thirds of the size of a full-grown adult.
Lyson said more than 100 individual T. rex fossils have been unearthed, but many are fragmentary. It is unclear yet how complete this fossil is. So far, they know they have found a leg, hip, pelvis, a couple of tailbones and a good chunk of the skull, Lyson said.
Jessin, a fan of the Jurassic Park movies and an aspiring paleontologist, has continued his fossil hunts, recently discovering a turtle shell.
For other kids, he advises: "Just to put down their electronics and go out hiking.”
