The emergence of the Tyrannosaurus rex, with its formidable teeth and strong jaws, occurred unexpectedly millions of years ago, marking the end of the dinosaur era.

The origin of this phenomenon has been a subject of curiosity for paleontologists for a considerable amount of time. A team of researchers from various universities and the New Mexico Museum of Natural History and Science claim to have uncovered another crucial aspect of this puzzle.

On Thursday, they presented evidence of fossils and shared their discoveries in the publication Scientific Reports. Their research identifies a novel subspecies of tyrannosaur that is believed to be an earlier and less advanced ancestor of the famous T. rex.

The group of schoolchildren were filled with awe and excitement as they saw the large jaw bone and sharp teeth. Fragments of the delicate specimen were initially discovered in the 1980s by individuals on boats along the shore of New Mexico’s biggest reservoir.

The discovery of the new subspecies was the result of a detailed review of the jaw and other parts of the skull that were gathered at the location over a period of years. The researchers carefully studied each bone of the specimen, observing variations in multiple characteristics that differed from those typically associated with T. rex.

Anthony Fiorillo, the executive director of the museum and co-author of the study, stated that science is an ongoing process. Each new discovery prompts us to retest and question our previous understanding, which is the central theme of this project.

The differences between T. rex and Tyrannosaurus mcraeensis are subtle. But that’s typically the case in closely related species, said Nick Longrich, a co-author from the Milner Centre for Evolution at the University of Bath in the United Kingdom.

He stated that over the course of millions of years, evolution gradually leads to the accumulation of mutations, resulting in subtle differences in appearance among species.

According to the examination, the recently discovered subspecies, Tyrannosaurus mcraeensis, was not a direct precursor of T. rex but rather a separate branch in the species’ development.

The scientists discovered that it existed before T. rex by as much as 7 million years, indicating that tyrannosaurs were present in North America much earlier than previously believed by paleontologists.

The T. rex is known for being a formidable predator, with a length of up to 40 feet (12 meters) and a height of 12 feet (3.6 meters). According to study co-author Sebastian Dalman and other researchers, the T. mcraeensis was similar in size and also had a carnivorous diet.

Paleontologist Thomas Richard Holtz of the University of Maryland, who was not part of the research team, stated that the tyrannosaur fossil discovered in New Mexico has been recognized for some time, but its importance was not fully understood.

An intriguing finding from the study is that T. rex’s nearest relatives were primarily found in southern North America, except for Tarbosaurus in Mongolia and Zhuchengtyrannus in China, according to Holtz. This raises the question of whether the Asian tyrannosaurs migrated from North America, or if the newly discovered subspecies and other large tyrannosaurs actually originated in Asia.

Holtz stated that a major obstacle in answering this question is the lack of suitable fossil locations in Asia that predate Tarbosaurus and Zhuchengtyrannus. As a result, we are unable to determine if their predecessors existed in that region.

He and the scientists who studied the sample both concur that additional fossils from the Hall Lake Formation in southern New Mexico could provide answers to additional inquiries.