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
Lexile

Assign to Google Classroom

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. It was 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. But, 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.

Filed Under:  
Assigned 184 times
CRITICAL THINKING QUESTION
Why did huge dinosaurs evolve from smaller ancestors?
Write your answers in the comments section below


COMMENTS (53)
  • charliet-orv
    3/21/2016 - 03:02 p.m.

    Well metaphorically speaking everything has to start out small.

  • brycep-kut
    3/21/2016 - 03:11 p.m.

    This is suprising that these scintest found a new typ of dinosaour .There can be a massive clue of what happend to the dsorse .There maybe a nother typ of dinosour that could be located close

  • ethang-1-bar
    3/21/2016 - 03:23 p.m.

    Huge dinosaurs had to evolve from little ancestors because they needed to adapt to their environment to survive and thrive.I found this article very interesting because it showed me what paleontologists can discover and unravel from just a bone.It makes me wonder what we can find out from a whole set of bones.

  • aidano-1-bar
    3/21/2016 - 03:27 p.m.

    T. Rex and other huge predators evolved from smaller ancestors. This is due to the simple science of adaptation. The T. Rex adapted to its massive and killer prone environment by growing in size and strength. This gave them the ability to hunt other dinosaurs, giving them domination in the Jurassic Era. I found this article interesting because I did not know that the T. Rex started as a small animal in the wild.

  • zachs-kut
    3/21/2016 - 03:28 p.m.

    We have never put that much thought into it we were distracted by the looks and body features. Also the amazing attacks it has and strategies.

  • kayleeu-2-bar
    3/21/2016 - 06:55 p.m.

    Huge dinosaurs evolved from smaller ancestors because everything comes from something smaller and then learns to adapt to their surroundings which can change their traits. Dinosaurs like the "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." This quick growth led to the tyrannosaurus Rex becoming a large and feared creature that dominated its time.

    my opinion on this article is that its crazy such a large animal can come from such a smaller creature.

  • corbenst-
    3/22/2016 - 10:00 a.m.

    How do you know that it was there ancestors?
    it could just be a smaller version of a t-rex
    like a micro pig ,or a teacup chihuahua.

  • noahh-1-nic
    3/22/2016 - 01:06 p.m.

    Because they needed to evolve to hunt new prey. They needed to git bigger for more prey and more to eat. They had to hear better so they could find food.

  • elijahb-kut
    3/22/2016 - 02:18 p.m.

    Man that t.Rex ear was big I cant belive that it could hear high and low sounds it is like it was a mutant T.Rex

  • chopink-kut
    3/22/2016 - 11:21 p.m.

    I thinks it's fascinating to see that people are doing more research on animals that are alike the monster the T. rex

Take the Quiz Leave a comment
ADVERTISEMENT