Brains before brawn: How the T. rex became king

Reconstruction of the new tyrannosaur Timurlengia euotica in its environment 90 million years ago.

Story highlights

  • Scientists have discovered a new species of dinosaur, called "Timurlengia euotica"
  • The dinosaur is a distant relative of the T. rex and offers clues to its evolution

(CNN)Scientists have discovered a new species of Tyrannosaur that helps explain how the T. rex turned into such a giant beast.

A team of experts from Edinburgh University, along with colleagues from Russia and the U.S., discovered fossilized remains in Uzbekistan and identified a new species called "Timurlengia euotica."
    The Timurlengia was roughly the size of a horse. It was "a nimble pursuit hunter with slender, blade-like teeth, suitable for slicing meat," says Hans Sues, chair of the Department of Paleobiology at the Smithsonian's National Museum of Natural History.
    It had long legs, was a fast runner, and probably preyed on plant-eaters, but its speed wasn't the only thing the researchers were interested in -- when the creature's skull was reconstructed they discovered its brain and ears looked very familiar.
    "Ancestors of the T. rex would have looked a whole lot like Timurlengia," says Steve Brusatte, team leader from the University of Edinburgh.

    Head first

    Until now, little was known about how Tyrannosaurs became the giant predators that dominated the landscape about 70 to 80 million years ago.
    The first Tyrannosaurs lived during the Jurassic Period and were only slightly larger than human, but 100 million years later they had evolved into creatures that could weigh up to 7 tons -- the T. rex of legend.
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    At 90 million-years-old, the newly discovered species fills in the gaps.
    Scientists used CT scans of the new dinosaur's brain to gain an understanding of its senses. While the skull of the creature was far smaller than that of the T. rex, its brain and senses were already highly developed.
    According to the experts, this shows that before Tyrannosaurs became so huge, they already had its legendary cunning, and a very keen hearing ability.
    This would have put them in an excellent position to roar to the top of the food chain.
    "Only after these ancestral Tyrannosaurs evolved their clever brains and sharp senses did they grow into the colossal sizes of T. rex," says Brusatte.
    "Tyrannosaurs had to get smart before they got big."