Paleontologists have lengthy debated the origins of one of the iconic dinosaurs, the Tyrannosaurus rex. Whereas many fossils have been present in North America, some researchers questioned whether or not the species really originated there or if its ancestors migrated from elsewhere.
A recent study led by paleoecologist Cassius Morrison from College School London sheds new mild on this thriller, suggesting that the direct ancestors of T. rex could have migrated from Asia throughout the traditional Bering Strait.
Tracing Tyrannosaurus rex Migration Throughout Continents
The worldwide analysis group used fashions that mixed the fossil file, dinosaur evolutionary timber, and local weather and geographic knowledge of the Late Cretaceous interval. Morrison explains, “Dozens of T. rex fossils have been unearthed in North America, however our findings point out that the fossils of T. rex‘s direct ancestor could lie undiscovered nonetheless in Asia,”
This aligns with earlier research displaying that T. rex was extra intently associated to Asian family members corresponding to Tarbosaurus than to different North American tyrannosaurids like Daspletosaurus.
In 2024, one other group reported a fossil of Tyrannosaurus mcraeensis present in New Mexico that predates T. rex by about six million years. This led some to argue that giant tyrannosaurs originated in North America. Nevertheless, Morrison’s group challenges this declare, citing the restricted variety of specimens and technological constraints affecting the age estimates.
The Untold Story Of Dinosaur Predators Taking Over
The group highlights that fossils of small tyrannosaur family members have recommended migration through the Beringian land bridge, which linked Asia and North America. The examine additional particulars the evolutionary journey of different predatory dinosaurs like megaraptors, which originated in Asia round 120 million years in the past.
These predators later unfold to Europe and Gondwana, the southern supercontinent. Paleontologist Mauro Aranciaga Rolando from Argentina’s Bernardino Rivadavia Pure Sciences Museum factors out that megaraptors had been “a part of a widespread and numerous dinosaur fauna” early of their evolution.
Over time, as continents drifted apart, megaraptors grew to become extremely specialised. In areas corresponding to Asia, tyrannosaurs finally changed them, whereas in Australia and Patagonia, megaraptors developed into apex predators dominating their ecosystems.
Gigantism And Environmental Adaptation In Tyrannosaurs And Megaraptors
The analysis reveals that round 92 million years in the past, each megaraptors and tyrannosaurids grew to monumental sizes as the worldwide local weather cooled. But, the examine finds no direct hyperlink between local weather change and this gigantism.
As a substitute, these dinosaurs could have tailored higher to cooler environments, which allowed them to fill the apex predator area of interest left vacant after the extinction of large carcharodontosaurid theropods round 90 million years in the past.
Charlie Scherer, a paleontologist at UCL and co-author of the examine, explains, “They doubtless grew to such gigantic sizes to exchange the equally large carcharodontosaurid theropods that went extinct about 90 million years in the past. This extinction doubtless eliminated the ecological barrier that prevented tyrannosaurs from rising to such sizes.”
