Newly Discovered T. rex Species Unveiled in Groundbreaking Study

In a groundbreaking study, scientists have identified a previously unknown relative of the iconic Tyrannosaurus rex, shedding light on the evolutionary chain that led to the massive predatory dinosaur. The newly named species, Tyrannosaurus mcraeensis, is believed to have roamed the Earth up to 7 million years before the emergence of T. rex. This discovery not only adds to our understanding of dinosaur evolution but also provides valuable insights into the diversity and adaptations of these ancient creatures.

T. rex vs. its relative

The study reveals two significant differences between T. rex and T. mcraeensis. The lower jaw of T. mcraeensis is more slender compared to the robust jaw of T. rex, indicating a variation in bite force. Additionally, T. mcraeensis lacked the prominent ridge over its eyes, which is believed to have served as a mate attraction feature in T. rex. The subtle ridge in T. mcraeensis suggests different evolutionary adaptations and behaviors.

Why go large?

Researchers speculate that the emergence of massive tyrannosaurs like T. rex was due to the availability of large herbivores as prey. However, the exact reasons behind the evolution of giant plant-eating dinosaurs remain a mystery. Unlike the pygmy tyrannosaur found in the Arctic, T. mcraeensis experienced a more stable environment and was able to continue growing. Further investigation into the paleoecology and environment in which T. mcraeensis lived will provide insights into its unique adaptation to a large size.

A tyrannosaur sleuth

The identification of T. mcraeensis was made possible thanks to the diligent work of paleontologist Sebastian G. Dalman. While studying the bones, Dalman suggested that they might belong to a different species, leading to this groundbreaking discovery. The fascination with T. rex, fueled by its depiction in popular culture, has increased the attention given to the search for more T. rex specimens. This, in turn, has expanded the sample size available for scientific research and aided in the identification of new species.


  1. How was the newly discovered T. rex species identified?

    • The identification was made by paleontologist Sebastian G. Dalman, who noticed distinct differences in the bones during his study.
  2. What are the major differences between T. rex and T. mcraeensis?

    • T. mcraeensis has a slender lower jaw and lacks the prominent ridge over its eyes, distinguishing it from T. rex.
  3. Why did massive tyrannosaurs like T. rex evolve?

    • Scientists believe that the evolution of large tyrannosaurs was driven by the availability of large herbivores as prey.
  4. Why did T. mcraeensis grow larger than other tyrannosaurids from the same time period?

    • Unlike the Arctic-dwelling pygmy tyrannosaur, T. mcraeensis inhabited a more stable environment, allowing for continued growth.
  5. How has popular culture influenced the study of T. rex?

    • The depiction of T. rex in movies and its iconic status have fueled increased attention from scientists and amateur fossil hunters, leading to the discovery of new T. rex specimens.

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