Where did T. rex come from? Fossil provides a clue Hans-Dieter Sues, chair of the Department of Paleobiology at the Smithsonian's National Museum of Natural History, holds a vertebra fossil from a new dinosaur, Timurlengia euotica, during a news conference in Washington, Monday, March 14, 2016. The image in the background is of the braincase of the Timurlengia euotica. (AP Photo/Susan Walsh)
Where did T. rex come from? Fossil provides a clue
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How did evolution produce a monstrous killer like T. rex? A fossil find in Central Asia is giving scientists a glimpse of the process.
 
T. rex and other tyrannosaurs were huge, dominant predators but they evolved from much smaller ancestors. The new discovery from Uzbekistan indicates that this supersizing happened quickly, and only after the appearance of some anatomical features that may have helped the monster tyrannosaurs hunt so effectively.
 
The finding was reported by Hans-Dieter Sues of the Smithsonian's National Museum of Natural History in Washington, Stephen Brusatte of the University of Edinburgh in Scotland and others. They wrote a paper that was released by the Proceedings of the National Academy of Sciences.
 
They report finding bones of a previously unknown member of the evolutionary branch that led to the huge tyrannosaurs. This earlier dinosaur lived about 90 million years ago. It lived south of what is now the Aral Sea. It looked roughly like a T. rex, but was only about 10 to 12 feet long. It weighed only about 600 pounds at most, Sues said. T. rex grew about four times as long and weighed more than 20 times as much.
 
The discovery helps fill in a frustrating gap in the tyrannosaur fossil record. Before that gap, which began some 100 million years ago, the ancestral creatures were only about as big as a horse. Right after the gap, at about 80 million years ago, tyrannosaurs were multi-ton behemoths like T. rex. The new finding shows the forerunners were still relatively small even just 90 million years ago. So the size boom happened pretty quickly.
 
The inner ears of the newfound beast already had tyrannosaur features associated with good agility and hearing low-pitched sounds. Those might have helped it detect prey or other animals at a distance. However, the creature lacked the massive, bone-snapping teeth and large sinuses found in T. rex.
 
The creature was dubbed Timurlengia euotica (TEE-mer-len-GEE-uh yoo-OH-tih-kuh). The name honors the ancient Central Asian ruler Tamerlane and the large inner ears of the beast. The fossils include a braincase and bones from the neck, back, tail, feet and hands. The creature wasn't a direct ancestor of T. rex. But it indicates what such ancestors looked like, Brusatte said.
 
The discovery helps scientists understand how "the (anatomical) parts got put together ... on the path to T-rex-hood," said Thomas R. Holtz, Jr. of the University of Maryland. Holtz didn't participate in the study. It also suggests where to dig for more fossils to investigate the transition, he said.

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Why did huge dinosaurs evolve from smaller ancestors?
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COMMENTS (28)
  • collinf-2-bar
    3/21/2016 - 07:44 p.m.

    The huge dinosaurs evolved from smaller ancestors because the ancestors they had good hunting traits. "The inner ears of the newfound beast already had tyrannosaur features associated with good agility and hearing low-pitched sounds."

    I found this article interesting because I find dinosaurs fascinating.

  • Steve0620-yyca
    3/21/2016 - 09:22 p.m.

    There is a new discovery of a fossil from Uzbekistan. It is the fossil of a dinosaur that is similar to the Tyrannosaurus Rex. This dinosaur was nicknamed as the Timurlengia euotica. This fossil shows how the dinosaur hunted and some of its talents in hunting. These dinosaurs had a very good sense of hearing and could track its prey down well. There was a gap in the time period of the dinosaurs which the scientists found. There has been a drastic increase in size of the dinosaurs between one hundred million and eighty million years ago. That is why the Tyrannosaurus Rex is larger than its ancestors. I hope that this discovery will lead to many more findings and conclusions.

  • karliw-1-bar
    3/21/2016 - 10:36 p.m.

    The most famous dinosaur known to man, the T-Rex, probably evolved from a smaller ancestor because of the process of evolution. Evolution, the process by which a species develops and adapts to a specific environment over time, is the reason why the frustrating, gaping, growth spurt of the T- Rex has been filled. The somewhat distant ancestor, Timurlengia euotica, had already developed the "inner ears of the newfound beast already had tyrannosaur features associated with good agility and hearing low-pitched sounds." Although Timurlengia lacked the "massive, bone-snapping teeth and large sinuses found in T. rex.", Thomas R. Holtz said of the discovery that it "helps scientists understand how 'the (anatomical) parts got put together ... on the path to T-rex-hood,' ". Because of this, scientists could connect the two beasts to form the conclusion that the famous, sickly bloodthirsty T-Rex decended from the Timurlengia euotica.

  • kieranw-3-bar
    3/23/2016 - 11:15 p.m.

    Huge dinosaurs evolved from smaller ancestors because when the species first existed the original ancestors size suited the dinosaurs needs. But after the dinosaur became the runt of the litter the dinosaur evolved into what is now called a T- Rex. This beast evolved from a dinosaur the size of a horse into an animal bigger then any we have today. I find this article very fascinating because I love archeology and so when I hear of a new lead upon dinosaurs or ancient times I immediately read. I thought this article was really informative and the connections between the ancestor of the T- Rex being the size of the horse helped me put the actual size into mind.

  • ethang-1-bar
    3/25/2016 - 12:23 a.m.

    Huge dinosaurs evolved from smaller ancestors to be able to survive the competition and struggle in their environment.They could evolve hunting skills both physically and mentally to kill prey and acquire food.I found this article interesting because it shows how scientists can find new observations and discoveries on major objects both living and non-living.

  • ethany-fel
    4/20/2016 - 02:12 p.m.

    Huge dinosaurs evolved from smaller ancestors because they developed

  • victoriae-fel
    4/20/2016 - 02:12 p.m.

    Huge dinosaurs evolve from smaller ancestors because they have good hearing which is good for hunting.

  • callans-fel
    4/20/2016 - 02:12 p.m.

    The huge dinosaurs evolved from smaller ancestors because over time, the smaller version of them grew bigger, just like us humans are getting taller with each generation.

  • johnj-fel
    4/20/2016 - 02:13 p.m.

    Huge dinosaurs evolved from smaller ancestors because at first they ate anough and hunted enough to satisfy their own needs but as time went on they needed more and they grew.

  • hollyk-fel
    4/20/2016 - 02:13 p.m.

    Huge dinosaurs evolved from smaller ancestors because as said in the article "The new discovery from Uzbekistan indicates that this supersizing happened quickly, and only after the appearance of some anatomical features that may have helped the monster tyrannosaurs hunt so effectively." So the huge dinosaurs such as the T. rex and other tyrannosaurs gets there hunting skills from there smaller ancestors.

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