Newly Found Giant Tyrannosaurus Predates T. Rex by 6 Million Years

For sophisticated 10-year-olds looking to stand out, they now have a fresh dinosaur name to flaunt as their favorite – Tyrannosaurus mcraeensis. This recently identified species seems to be less evolved than its well-known relative, but it’s equally large and intimidating.

It’s understandable why T. rex has captivated the public’s imagination; the allure of an ancient superpredator the size of a double-decker bus is undeniable. Despite the new species having a less exciting name, T. mcraeensis, derived from the rock layers where it was discovered, one wouldn’t downplay its stature. This dinosaur still measured 12 meters (39 feet) in length and weighed 10 tons, resembling a formidable tank armed with a mouthful of teeth.

Identifying T. mcraeensis as a New Species

The distinctions between the two species are nuanced and might not be readily discernible if confronted by both at the same time. In comparison to T. rex, T. mcraeensis exhibited a longer but shallower lower jaw with blunter teeth, and its chin and the protrusions above its eyes were less pronounced. While these variations may seem subtle, the team identified a consistent pattern of differences, leading them to designate it as a new species.

According to co-author Nick Longrich, “Every single bone is slightly different from the corresponding element in T. rex. Since we have lots of T. rex fossils, we have a reasonable idea of what sort of variation exists in a T. rex, and this animal consistently lies outside of that range of variation, in every single bone of its skeleton.”

T. mcraeensis Predates T. rex by 6 Million Years

The most notable distinction, the team asserts, is the age of the fossil. T. mcraeensis roamed North America at least 72 million years ago – roughly 6 million years before T. rex emerged. This suggests a more primitive status, and although it may not be a direct ancestor, it could contribute valuable insights into the evolution of Tyrannosaurus.

Previously, the closest known relatives, like Tarbosaurus, were exclusively found in Asia, implying an origin there and migration via Siberia and Alaska. In contrast, the new discovery suggests that Tyrannosaurus evolved in southern North America and then migrated north, aligning with the migration patterns observed in other dinosaur species.

The arrival of T. mcraeensis coincides with a turbulent period in paleontology. Some experts have proposed that T. rex comprises three distinct species, introducing names like T. regina and T. imperator. Simultaneously, a debate centers on whether fossils of smaller tyrannosaurs constitute a separate species called Nanotyrannus or are simply juvenile T. rexes. It’s noteworthy that Nick Longrich, a co-author of this study, aligns with Team Nanotyrannus in this parallel debate.

Further investigation will be necessary to unravel the complexities of this intricate family tree.

Read the original article: New Atlas

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