New Study On Tyrannosaurus Rex Predecessor

Sterling Nesbitt volunteered as a teen at the Arizona Museum of Natural History in Mesa. She helped discover fossils of a 3-foot-tall early relative of the Tyrannosaurus rex.

Now, almost 20 years later, Nesbitt has authored a paper that was published recently in the journal Nature Ecology and Evolution.

The paper provides details of the dinosaur called Suskityrannus hazelae, and the information it’s provided on the missing clues about the evolution of the Tyrannosaurus rex that evolved into the massive predator that ruled the later Cretaceous period.


“My discovery of a partial skeleton of Suskityrannus put me onto a scientific journey that has framed my career,” Nesbitt wrote.

The name means “Hazel’s coyote tyrant.” It’s from the Zuni word for coyote, suski, and it’s a reference to field project worker Hazel Wolfe.

The skeletons were found in the Zuni Basin of western New Mexico between 1996 and 1998. They are 92 million years old; 27 million years older than the Tyrannosaurus rex.

“The new species shows that tyrannosaurs developed many of their signature features, like a muscular skull, broad mouth and a shock-absorbing foot, when they were still small, maybe as adaptations for living in the shadows,” said Steven Brusatte, a co-author of the paper..

The scientists say Suskityrannus was 9 feet long, 2-3 feet tall at the hip, and weighed 45-90 pounds. It stood on two legs and had teeth that suggested a carnivorous diet. By comparison, the Tyrannosaurus rex weighed around 9 tons.

The Arizona Museum of Natural History will permanently house the Suskityrannus fossils.

Douglas Wolfe, from the museum’s Zuni Basin Paleontological Project, called the discovery “a very successful example of collaboration between scientific professionals, students, and volunteers working to narrow the ‘Cretaceous dinosaur gap.” .

Click here to learn more information and how you can visit the display at the Arizona Museum of Natural History.