FILE: Fossil displays at the Natural History Museum of Utah. Photo credit: The University of Utah.
SALT LAKE CITY, Utah — There’s a new dinosaur in town: Allosaurus jimmadseni was a meat-eating allosaurus species that lived in North America 155 million years ago.
Its specimens were found at Dinosaur National Monument and in Emery County. Paleontologists announced the discovery Friday at the Natural History Museum of Utah.
The new dinosaur was named after Jim Madsen, Jr., the first paleontologist in Utah. Madsen dedicated his life to paleontology, so the museum chose to honor his scientific and conservation work through this fossil name, according to a statement from the museum.
The dinosaur is an older version of the Allosaurus fragilis, which is also on display at the Natural Museum of Utah.
“This animal actually lived before Allosaurus fragilis,” said Mark Loewen, a paleontology research associate at the Natural History Museum. “Allosaurus jimmadseni represents the only other species of Allosaurus that lived in North America.”
Both species are part of the same genus Allosaurus, which is Utah’s state fossil.
These dinosaurs lived during the Jurassic and Cretaceous periods. Allosaurus jimmadseni has a short narrow skull with low facial crests extending from the horns in front of the eyes forward to the nose. There’s also a relatively narrow back of the skull.
“The lower part of its jaw is more straight, the skull is narrower,” Loewen said. “This makes it a little bit more gracile compared to the stronger skull we have in Allosaurus fragilis.”
A foot, some toe bones and a few tail bones were found in 1990. Paleontologists then excavated the quarry face, and saw more of the skeleton — except the skull. A few years later, technology revealed more bone just below the surface, and they found the skull close by.
A complicated helicopter lift was required to bring the specimen back to the lab.
It was deemed a significant find, but missing something: the skull.
After further efforts of excavation, the skull was finally found separated from the body. The great skeleton was complete after two separate discoveries.
After years of two different groups coming together to study the remains, the fossil is no longer a secret and the state can learn more about the ancient species.