Rare fossil of adolescent Tyrannosaurus - 'Teen Rex'- found by US kids
In a remarkable find, a rare fossil of an adolescent Tyrannosaurus rex has been excavated in the badlands of North Dakota. This discovery is noteworthy not only for the scientific insights it may offer into the life history of this famous dinosaur, but also for the intriguing tale of the young explorers who stumbled upon it.
The fossil, affectionately nicknamed "Teen Rex," was announced on Tuesday by the Denver Museum of Nature & Science, where it will be studied and displayed. In July 2022, brothers Liam Fisher, 9, and Jessin Fisher, 12, along with their cousin Kaiden Madsen, 11, were hiking and searching for fossils with their father, Sam Fisher, on land managed by the U.S. Bureau of Land Management near the town of Marmarth in southwestern North Dakota.
While exploring the area, Liam and his father noticed a large leg bone protruding from the ground. "My dad hollered for Jessin and Kaiden to come, and they came running," Liam recounted. "And dad asked, 'What is this?' And Jessin said, 'That's a dinosaur.'"
Sam Fisher promptly texted a photo of the discovery to paleontologist Tyler Lyson, a Marmarth native and his former high school classmate, who now serves as the curator of vertebrate paleontology at the Denver Museum of Nature & Science. Lyson obtained the necessary excavation permits, and in July 2023, the team returned to the site to carefully uncover the fossil.
Initially, it appeared the leg belonged to a plant-eating duckbilled dinosaur. "However, on day one of the excavation, Jessin and I uncovered the lower jaw with several big T. rex teeth sticking out of it," Lyson said, describing the moment with excitement. "It still gives me goosebumps."
Kaiden, now 11 years old, was equally amazed by the discovery, saying, "I was completely, like, speechless."
The Tyrannosaurus fossil, estimated to be around 13-15 years old and two-thirds the size of an adult, measures 25 feet (7.6 meters) in length and weighs 3,500 pounds (1,600 kg). This specimen is slightly larger than another juvenile T. rex fossil, known as "Jane," housed at the Burpee Museum of Natural History in Rockford, Illinois.
Tyrannosaurus, one of the largest meat-eating dinosaurs, roamed the western regions of North America during the late Cretaceous Period, approximately 67 million years ago, shortly before the mass extinction event that wiped out all non-avian dinosaurs.
The fossil was found in the Hell Creek Formation, an area that "preserves Earth's last dinosaur ecosystem" before the asteroid impact that led to the extinction, according to Lyson. Based on the soft sandstone in which the specimen was discovered, it appears the animal's body ended up on a sandbar in an ancient river system.
The completeness of the skeleton remains uncertain, as much of it is still encased in a three-ton rock chunk being studied at the museum. However, it is known that the fossil includes a significant portion of the skull, the hipbone, and some vertebrae, in addition to the previously discovered leg.
Juvenile Tyrannosaurus had a different body type compared to their adult counterparts, being more gracile and speedy, with a more streamlined skull. This discovery could provide valuable insights into the growth rate and physical changes of the Tyrannosaurus during its maturation process, as only a handful of such juvenile fossils are available for study.
The excavation of this remarkable fossil was captured by a documentary crew, and the film "T. REX" is set to be released on June 21, offering the public a glimpse into this extraordinary scientific endeavor.
