Mini T-Rex: It's Like a chihuahua, only awesome!

[Acturus]

Mini T. Rex Recovered : Scientific American Podcast

Mini T. Rex Recovered
In a study in the journal Science, researchers announce the discovery of a dinosaur 125 million years older and one-nintieth the size of T. Rex, but having virtually the same body plan as the giant dino. Cynthia Graber reports.

[The following is an exact transcript of this podcast.]

Ask any young dinosaur fanatic about the mighty Tyrannosaurus rex and you’ll probably get a fairly accurate description: huge reptile, big head, powerful jaws, tiny little arms. Scientists had thought that the animal evolved its bizarre proportions as it grew to its gargantuan stature. But in this week’s issue of the journal Science, paleontologist Paul Sereno describes a newly discovered miniature tyrannosaurid that evolved millions of years earlier—and has all the attributes of the larger one.

The tiny dino had been excavated in Mongolia illegally and sold to a private collector. He contacted Sereno to evaluate the preserved tyrannosaurid. Sereno agreed to do so if the dinosaur was donated to science, and eventually returned to China.

The dinosaur is about nine feet long and had an estimated weight of only 150 pounds. But it’s all there—the tiny arms, the huge head, the large teeth and muscular jaw. A hundred-twenty-five million years later, that animal’s descendants had ballooned into an almost exact replica more than 90 times larger. Sereno and his colleagues say the body plan must have been a successful structure for hunting prey—and ultimately thrilling dinosaur lovers everywhere.

—Cynthia Graber

See a side-by-side comparison of the skulls of T. rex and the new dino.

Picture of the skull comparison:

Spoiler: show

http://www.scientificamerican.com/me...A85B398E26.jpg

Millions of years before the first tremendous Tyrannosaurus rex began terrorizing fellow animals, Raptorex kriegsteini showed all of the characteristic tyrannosaur features—in miniature.

Weighing in at about 1 percent of the latter theropod's mass, Raptorex hunted with the same bipedal gait, stubby arms and keen sense of smell as its daunting cousin. Despite being a fairly diminutive dino, it still was nearly three meters long, weighed about 80 kilograms and would have been a fearsome match for a midsize mammal like a human.

"There's no other example that I can think of where an animal has been so finely designed at about 100th the size that it would eventually become," Paul Sereno, a paleontologist at the University of Chicago, said in a prepared statement. He and five other co-authors describe the new carnivore in a paper in Science today.

In this image, the Raptorex's skull is shown to be just a fraction the size of a full-grown T. rex skull.

[Kerberoz]

fairly accurate description: huge reptile

Huh.

[Woozie]

Huh.

Are Tyrannosaurus' not reptiles? Serious question, I really don't know. I grew up learning in school that they were, but then I saw something in the history channel a few weeks ago that said they were something in between reptile and something else. And I also heard that they probably weren't completely cold blooded like normal reptiles. I also heard on the same show that T-rex probably didn't actually hunt much, but was more like a scavenger that hunts whenever it can, but would rather steal food from other hunters (kinda like a hyenna). How much of this is true?

[Qalbert]

if its 1/90th the size and nine feet long, then a regular t-rex is 810 feet long?

[Feielle]

The on-going debate back when I was in school was whether or not Dinosaurs were more closely related to birds than to reptiles. I believe evidence was leaning toward the bird side of the argument, but it isn't something I've kept up with.

[Woozie]

if its 1/90th the size and nine feet long, then a regular t-rex is 810 feet long?

When they said size, were they referring to mass or length? Sometimes people will say "20 times larger" and actually mean "20 times heavier". Or maybe both, since it's nearly an exact replica.

[Woozie]

The on-going debate back when I was in school was whether or not Dinosaurs were more closely related to birds than to reptiles. I believe evidence was leaning toward the bird side of the argument, but it isn't something I've kept up with.

Yeah, I know dinosaurs became birds, but what exactly were dinosaurs classified as? Or did they have their own category seperate from both birds/reptiles/everything else? And were reptiles already around when dinosaurs were around? What kind of mammals were around at the time?

[Mizango]

Yes it is technically a reptile and like Feielle yes they are more closely related to birds than anything and vice versa. Also unlike reptiles there may be new evidence (Since Science requires proof we test everything before we deem it fact) that Dinosaurs may not have been cold blooded after all.

You should read up on the Chicken genome. Thanks to the Wieschaus and Nusslein-Volhard, we are finding mutations in genes like the sonic hedgehog gene that gives chickens the 3 fingers that make up the wing tip, the scales on their legs and feet and even teeth bumps when they are in embryo form.

Now as the Chicken develops this gene turns off and the "teeth" recede so to speak. We have also simulated certain genes in embryos and have given chickens 12 boned feathered tails. Read Neil Shubins "Your inner fish" if this intrigues you.

[Mizango]

Found an old post of mine that has a link to the Dr. Shubin's book if anyone is interested in reading it online. My post talks about the same gene listed above as well.

http://www.bluegartr.com/forum/75180...ml#post2800299

But anyway, yes they are still considered "Thunder Lizards" and reptiles although we are finding evidence to the contrary.

[Jodwahh]

Maybe its just a baby T-Rex?

[Jaybar]

And were reptiles already around when dinosaurs were around?

For one, Alligator-like reptiles were around for a long time. No comment on the mammals because I'm not sure what types were around then.

Also 1/90th size is probably mass. They made reference to the ratio and it's weight in one of the quotes.

To poster above; I don't recall T-rex's being excavated in that time period (i.e. 125m years before T-rex)

[Mizango]

Maybe its just a baby T-Rex?

No.

Just like how midgets are not babies. Simplicity is nice but is not always the answer.

[Jodwahh]

Orz, well that shit in my pancakes lol. I wonder how it would taste if you ate it.

[Qalbert]

For one, Alligator-like reptiles were around for a long time. No comment on the mammals because I'm not sure what types were around then.

Also 1/90th size is probably mass. They made reference to the ratio and it's weight in one of the quotes.

To poster above; I don't recall T-rex's being excavated in that time period (i.e. 125m years before T-rex)

I assumed so, but it was somewhat ambiguous so I made a joke.

[melbufrauma]

saw this article on science daily, here is their article probably the same idk
Tiny Tyrannosaur: T. Rex Body Plan Debuted In Raptorex, But 100th The Size

[Kerberoz]

Reptile/bird is a complex subject, but the current theory is that all dinosaur families are descendants of reptiles, and still classified as Reptilia, but definitely different enough from true reptiles to deserve their own class. There's overwhelming evidence that theropods (t-rex, allosaur, raptors, etc) were more closely related to modern birds than to reptiles, and also that dinosaurs in general were warm-blooded and shared more traits with birds than reptiles. "Dinosaur" refers to a wide range of species that were only loosely related.

tl;dr they weren't reptiles or birds

This fossil is pretty interesting, though. It'll be interesting to see if they can find more in the same area. 3 meters is tiny for anything from that time period.

[Lbelle]

http://upload.wikimedia.org/wikipedi...BeforeTime.jpg

he was 1/90th the size of his parents remember?

[Mizango]

Yet a boat the size of a mountain continues to elude us.

[tyven]

this story is a dino-snore

[Mizango]

Alternately, this is proof animals used to be 1/90th their size and thus Noah's ark was actually a canoe.

rofl.