Discovery of closest relative of 'Tyrannosaurus rex' sheds light on mystery of these predators | Sciences

The most famous dinosaurs are Tyrannosaurus rexIt was the largest predator of its time and perhaps of all time, but for the scientific community how these animals grew to become giants is a mystery. They weighed 10 tons, were 12 meters long, and had massive heads and teeth capable of crushing bones. The discovery of a new species of dinosaur may remove some of these doubts. Analysis of a skull found in New Mexico, United States, It is published today in Scientific reports And adding a What's new in the history tree of these dinosaurs: Tyrannosaurus macrinsis. He is the closest relative T-Rex It sheds light on the diversity, origin and size of these fearsome predators from the Late Cretaceous period.

“In paleontology, knowledge advances in two ways: by finding new fossils or by re-studying and reinterpreting previously found remains,” explains paleontologist Luis Alcalá, director of the Granada Science Park who has nothing to do with the discovery. To learn about this close to T-Rex, the second was used. A group of New Mexico scientists used computer programs that distinguish between different bones to classify species, and discovered that a skull found in Hole Lake, New Mexico, had been attributed to one of the organisms. T-Rex, but it actually belongs to a different dinosaur. Differences in the shape and union of fossil bones compared to bones T-Rex It's subtle, but important, enough to distinguish it as a different animal species.

New dinosaur Macrinsis—Which is named after the McRae Formation in New Mexico, where the remains of multiple dinosaurs have been found – it could have lived between 71 and 73 million years ago, five to seven million years before the appearance of dinosaurs. T-Rex. That's what the study by paleontologist Sebastian J. Dahlmann of the University of Massachusetts and colleagues suggests, based on the location of rocks and other remains from the Hall Lake area, where the skull was originally found.

Laramidia: Home of giant dinosaurs

“Although much is known about them, there are aspects that give rise to still open discussions about the origin of tyrannosaurids,” explains Fidel Torcida, director of the center. Salas de los Infantes Dinosaur Museum, Who did not participate in the study. Within the controversy, one of the hypotheses put forward by paleontologists is that these large dinosaurs appeared in Asia and moved to America, while a second theory suggests the opposite, meaning that they appeared in what is now known as North America and their number increased. In population, they moved towards Asia, and then returned to North America.

Discovery Tyrannosaurus macrinsis Supports the North American origin theory, suggesting that the evolutionary line of tyrannosaurids arose specifically in Laramidia, an island continent that existed between 100 and 66 million years ago in what are now Canada, the United States, and Mexico. The researchers also explain that these dinosaurs lived in the south of the region and were not always enormous in size. They went from being hunters of small species over a period Early Cretaceous period To be a predator of large herbivores while increasing their size.

In a small area like the island region, it would not be unusual for the species to be small or of a size that corresponds to where it lives. But this was not the case in Laramidia. On this island, “the temperature and absence of competitors and predators may have caused the area's herbivores to grow to the size of giant dinosaurs such as titanosaurs, ceratopsians, or hadrosaurs,” Torcida explains. The more herbivores there are, the more they eat. In this way, the authors suggest, they evolved toward the size of a giant body about 72 million years ago to the newly known size Tyrannosaurus macrinsis To lead, after millions of years, to the famous T-Rex.

Both Alcalá and Torcida consider it positive that a new species of dinosaur has been discovered. Discovery brings variety to the family Dinosaur It opens new avenues of exploration, urging researchers to delve deeper into the mysteries of ecosystems and the relationships between ancient world predators and prey. Alcala remembers that in Tyrannosaurus macrinsis It was initially classified as T-RexAnd “Could there be other types of dinosaurs?” he wonders.

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