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. 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.

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Why did huge dinosaurs evolve from smaller ancestors?
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COMMENTS (53)
  • kyleyc-kut
    3/21/2016 - 07:42 a.m.

    Dinosaurs are an interesting topic to say the least. mostly because of what little we know about them, and what science we use to find out what their life was like.

  • tyshawng-wes
    3/21/2016 - 09:28 a.m.

    Everything comes from something smaller than what it is things grow more and more everyday sometimes they shrink but most of the time they grow just like humans we grow everyday even phones get bigger.

  • joeg-orv
    3/21/2016 - 12:39 p.m.

    huge dinosaurs evolved from smaller ancestors just like tons of other animals including humans. Everything starts small and gets bigger and bigger.

    • jahir-orv
      3/21/2016 - 10:54 p.m.

      not everything starts small and gets big. Take a look at Dinosaurs to birds. Birds are the descendants to Dinosaurs

    • jahir-orv
      3/21/2016 - 10:57 p.m.

      Dinosaurs like all things Go through the process of evolution.

  • carlym-4-bar
    3/21/2016 - 01:10 p.m.

    Huge dinosaurs evolved from smaller ancestors because the small ancestors had to learn how to adapt to their environment so that it would be easier for them to hunt for food and resources. "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." This quote explains how the bigger dinosaurs were able to hunt easier than their smaller ancestors.
    I found this article very interesting because I learned why and how dinosaurs became larger.

  • siobhanw-wes
    3/21/2016 - 02:32 p.m.

    They evolved because of anatomical features.

  • myas-wes
    3/21/2016 - 02:34 p.m.

    The huge dinosors got bigger because everything on everything grows to be bigger even the thing that are huge and should have stopped growing still can grow I think that this story is so cool and should be turned into a book or lager story

  • marshallh-wes
    3/21/2016 - 02:34 p.m.

    Dinosaurs evolved to be bigger because a unknown member came into the T.rex family making them bigger in size. Before the T.rex gained size it was only about the size of a horse from 10 to 12 feet long.

  • kailynk1-wes
    3/21/2016 - 02:52 p.m.

    Huge Dinosaurs Evolve From Smaller Ancestors Because ate Supersizing Happended Quickly And Some Of The Anatomical Features That May Have Helped The Monster Tyrannosaurs Hunt So Effectively.

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