Researchers discover new tyrannosaur species in ‘duelling dinosaurs’ fossil | Dinosaurs

The fossilized remains of two dinosaurs engaged in combat have sparked new drama, suggesting that tiny specimens thought to be adolescent Tyrannosaurus rex could instead be separate, smaller species.

The “duel dinosaur” fossil, which reveals a triceratops battling a medium-sized tyrannosaur, was discovered in Montana by commercial fossil hunters in 2006 and dates to shortly before an asteroid impact that ended the reign of dinosaurs 66 million years ago.

It only became available for scientific research after its acquisition by the North Carolina Museum of Natural Sciences (NCMNS) in recent years.

Now, researchers say a detailed analysis of the fighting Tyrannosaurus Rex reveals that it is not a juvenile T rex as many thought, but an adult of a different species. Nanotyrannus lancensis.

“Our specimen is an adult Nanotyrannus weighing only 1,500 pounds after two decades of growth,” said Dr. Lindsay Zanno, study co-author from North Carolina State University and chief of paleontology at NCMNS.

“The anatomy of Nanotyrannus“, due to its higher number of teeth, enlarged hands, shorter tail, unique pattern of cranial nerves and sinuses, and smaller adult body size, is inconsistent with the hypothesis that this skeleton is an adolescent T rex,” Zanno said.

The name Nanotyrannus lancensis was previously attributed to a small skull that was reported from the Hell Creek Formation of Montana in 1946. However, experts later argued that the specimen, known as the Cleveland skull, was actually a juvenile T rex.

Now the study by Zanno and colleagues, published in the journal Nature, reveals Nanotyrannus lancensis was in fact a species in its own right which lived both and inhabited the same ecosystems as T rex.

Additionally, the team claims that the skeleton of a young dinosaur named Jane found in the Hell Creek Formation in 2001 is also not a young T rex but a new species of dinosaur. Nanotyrannus.

“Our study suggests that some specimens previously thought to represent juvenile T rex are rather Nanotyrannus“Zanno said.

She said the findings had important implications. “For decades, paleontologists have unknowingly used Nanotyrannus specimens as a model for T rex adolescents to understand the biology of Earth’s most famous dinosaur – studies of its locomotion, growth, diet and biological history. These studies require a second look,” she said.

Professor Steve Brusatte, of the University of Edinburgh, who was not involved in the work, said that for many years in his research on tyrannosaurs he had considered a set of smaller skeletons found in the same rocks as the T rex fossils to be T rex juveniles.

“I think new evidence from this exquisite new specimen housed at the North Carolina Museum of Natural Sciences shows that I was wrong — at least in part,” he said, adding that the dueling T. rex analysis offered “strong evidence.” Nanotyrannus was real.

But Brusatte said he was not convinced there were multiple species of Nanotyrannuswhile pointing out that the multitude of fossilized T rex adults that had been discovered suggested that there should also be fossilized juveniles.

“So I am not yet ready to proclaim that every little tyrannosaurus skeleton is Nanotyrannus” he said. “Some of them must be juvenile T rexes, and I think ultimately it will be very difficult to tell the adults or near-adults apart. Nanotyrannus of teenage T rex.»