A groundbreaking discovery by a team of researchers, including experts from the New Mexico Museum of Natural History and Science (NMMNHS), has unveiled a new dinosaur subspecies believed to be an older and more primitive relative of the iconic Tyrannosaurus rex. This finding reshapes scientists' understanding of the arrival of this formidable beast in North America.

The study, published in the journal "Scientific Reports," introduces the newly identified subspecies, named Tyrannosaurus mcraeensis. Despite being just as large as the T. rex, this predator is shown to be more ancient and primitive. The existence of T. mcraeensis challenges prior assumptions about the timeline and evolutionary history of these ferocious creatures.

The research was triggered by the discovery of a partial skull in western New Mexico several years ago. This finding prompted an in-depth study, which unveiled that the Tyrannosaurus was present in North America millions of years earlier than previously believed. The NMMNHS's executive director, Dr. Anthony Fiorillo, expressed his excitement, stating, "New Mexicans have always known our state is special, now we know that New Mexico has been a special place for tens of millions of years."

According to a press release from the museum, the T. rex, renowned as one of the largest and most dangerous terrestrial predators in history, "suddenly appeared" in North America approximately 66 million years ago. At that time, there were no known close relatives of the T. rex in the region, leaving scientists puzzled about the origins and evolutionary path of this fearsome species.

Co-author Sebastian Daman, who began reexamining dinosaur species collected from southern New Mexico in 2013 while still a student, made significant contributions to the study. Alongside other researchers, Daman discovered that T. mcraeensis, similar in size to the T. rex, was also a carnivorous creature.

Further analysis revealed subtle variations in the jaw bones, making it less likely that the T. rex was a direct ancestor to T. mcraeensis. However, this discovery opens up possibilities for future revelations and suggests that there may still be more to learn about tyrannosaurs.

Dr. Spencer Lucas, paleontology curator at NMMNHS, emphasized the significance of New Mexico's dinosaur fossils, stating, "Once again, the extent and scientific importance of New Mexico's dinosaur fossils becomes clear - many new dinosaurs remain to be discovered in the state, both in the rocks and in museum drawers!"

This groundbreaking discovery not only unveils a new dinosaur subspecies but also expands our knowledge of the presence and timeline of tyrannosaurus in North America. The study suggests that these awe-inspiring creatures roamed what is now the southern United States at least 72 million years ago, likely originating in that region before spreading across the western portion of North America. It reinforces the idea that there is still much to be explored and understood about the fascinating world of dinosaurs.