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New Study Shows Tyrannosaurus Rex Evolved Advanced Bird-Like Binocular Vision
Science News Online ^ | June 26 2006 | Eric Jbaffe

Posted on 07/03/2006 12:32:51 PM PDT by Al Simmons

In the 1993 movie Jurassic Park, one human character tells another that a Tyrannosaurus rex can't see them if they don't move, even though the beast is right in front of them. Now, a scientist reports that T. rex had some of the best vision in animal history. This sensory prowess strengthens arguments for T. rex's role as predator instead of scavenger.

Scientists had some evidence from measurements of T. rex skulls that the animal could see well. Recently, Kent A. Stevens of the University of Oregon in Eugene went further.

He used facial models of seven types of dinosaurs to reconstruct their binocular range, the area viewed simultaneously by both eyes. The wider an animal's binocular range, the better its depth perception and capacity to distinguish objectseven those that are motionless or camouflaged.

T. rex had a binocular range of 55, which is wider than that of modern hawks, Stevens reports in the summer Journal of Vertebrate Paleontology. Moreover, over the millennia, T. rex evolved features that improved its vision: Its snout grew lower and narrower, cheek grooves cleared its sight lines, and its eyeballs enlarged. ...

Stevens also considered visual acuity and limiting far pointthe greatest distance at which objects remain distinct. For these vision tests, he took the known optics of reptiles and birds, ranging from the poor-sighted crocodile to the exceptional eagle, and adjusted them to see how they would perform inside an eye as large as that of T. rex. "With the size of its eyeballs, it couldn't help but have excellent vision," Stevens says.

He found that T. rex might have had visual acuity as much as 13 times that of people. By comparison, an eagle's acuity is 3.6 times that of a person.

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T. rex might also have had a limiting far point of 6 kilometers, compared with the human far point of 1.6 km. These are best-case estimates, Stevens says, but even toward the cautious end of the scale, T. rex still displays better vision than what's needed for scavenging.

The vision argument takes the scavenger-versus-predator debate in a new direction. The debate had focused on whether T. rex's legs and teeth made it better suited for either lifestyle.

Stevens notes that visual ranges in hunting birds and snapping turtles typically are 20 wider than those in grain-eating birds and herbivorous turtles.

In modern animals, predators have better binocular vision than scavengers do, agrees Thomas R. Holtz Jr. of the University of Maryland at College Park. Binocular vision "almost certainly was a predatory adaptation," he says.

But a scavenging T. rex could have inherited its vision from predatory ancestors, says Jack Horner, curator of paleontology at the Museum of the Rockies in Bozeman, Mont. "It isn't a characteristic that was likely to hinder the scavenging abilities of T. rex and therefore wasn't selected out of the population," Horner says.

Stevens says the unconvincing scene in Jurassic Park inspired him to examine T. rex's vision because, with its "very sophisticated visual apparatus," the dinosaur couldn't possibly miss people so close by. Sight aside, says Stevens, "if you're sweating in fear 1 inch from the nostrils of the T. rex, it would figure out you were there anyway."

Stevens, K.A. 2006. Binocular vision in theropod dinosaurs. Journal of Vertebrate Paleontology 26(June):321-330.


TOPICS: Religion; Science
KEYWORDS: atheismsucks; atheistdarwinists; bewareofluddites; creationism; crevolist; darwindroolbib; darwinwasaloser; dinosaurs; evolution; flyingbrickbats; godsgravesglyphs; guess; heroworship; ignoranceisstrength; junk; paleontology; patrickhenrycrap; pavlovian; pavlovianevos; shakyfaithchristians; trash; trex; tyrannosaurus; useyourimagination; yecluddites; youngearthcultists; youngearthidiocy
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To: Southack
"Lets make a clear point: "selection" isn't in question."

I didn't say it was. I said the affects of it were.

"In short, any reference to "selection" is off topic at best, specious at worst, and more likely a simple-minded attempt at thread digression."

No, it goes to the heart of the matter. You are assuming mutations with no selection. That's nuts. It's the selection that keeps the body plan of the alligator what it is. Not the mutation rate (of which you have no idea what it is, as you made up your claims about it being slow).

BTW, your accusing ME of thread digressions is HILARIOUS since you have been digressing from one topic to another all night, in an unsuccessful attempt to back off from your many unsupported claims.

"Now, if you want to talk about random mutations, that's a more worthy topic of debate."

The two are intertwined, inseparably. I think you know this, but can't give in even an inch or your entire facade will crumble.

"Random (or not) "selection" is unworthy, however. It's non-controversial."

I never said it was controversial. I said that you were ignoring it's affects.

Keep flailing. The lurkers need some entertainment too.

301 posted on 07/03/2006 8:30:09 PM PDT by CarolinaGuitarman (Gas up your tanks!!)
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To: Southack
With all due respect, I noted neither a PHD in palaeontology, geology, or physics on your homepage....neither have you cited to any authority in repeating your 'arguments' which are about as related to the topic of science as the following cartoon was related to the film "Jurassic Park"...


302 posted on 07/03/2006 8:30:09 PM PDT by Al Simmons (Hillary Clinton is Stalin in a Dress)
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To: Charles H. (The_r0nin)
Your entire argument is based on a premise about what evolutionary theory postulates that is completely wrong. If you're going to argue against something, at least understand what you are arguing against first! Jeez...

He's stuck in a self-dug lying rut and cannot under any circumstances admit error lest he be damned to Hell for all eternity for being the troll that he is. So it goes with trolls.

303 posted on 07/03/2006 8:31:26 PM PDT by balrog666 (There is no freedom like knowledge, no slavery like ignorance. - Ali ibn Ali-Talib)
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To: Texas Eagle
How many tyranosaurs roamed the Earth?

Probably not that many compared to the other kinds of dinosaurs if they followed the usual rules about numbers for predators vs prey animals.

The big question about how tyranosaurs lived is how they would have hunted without having useful forelimbs. In today's world, hunters with teeth and claws (cats) can take on large prey singlehandedly while predators with just teeth (wolves and dogs) generally hunt in packs. Picture a pack of tyranosaurs coming after you?

304 posted on 07/03/2006 8:32:55 PM PDT by tomzz
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To: Texas Eagle

I have no clue. But I am sure that there is a palaeontologist out there who could help you out...given that we think that Sue was about 25 years old at time of death, we have a pretty good idea as to max life spans of a TRex...the question of how often it bred and what amount of square miles could support each individual are questions that can never be answered, but I am sure that we can make some assumptions and work up a numerical range for you.....however math is not my strong suit...what are you getting at, anyhow?


305 posted on 07/03/2006 8:32:58 PM PDT by Al Simmons (Hillary Clinton is Stalin in a Dress)
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To: CarolinaGuitarman
Yes, they found a 3 mm in diameter hard piece of bone that had to be treated with acids to get it *softened*. There were no blood cells, nor DNA found. It was as much *meat* as a pet rock is alive.

Says you... Here's what the Reuters article had to say:

Paleontologists forced to break the creature's massive thighbone to get it on a helicopter found not a solid piece of fossilized bone, but instead something looking a bit less like a rock.

When they got it into a lab and chemically removed the hard minerals, they found what looked like blood vessels, bone cells and perhaps even blood cells.

"They are transparent, they are flexible," said Mary Higby Schweitzer of North Carolina State University and Montana State University, who conducted the study.

She said the vessels were flexible and in some cases their contents could be squeezed out.

"The microstructures that look like cells are preserved in every way," added Schweitzer, whose findings were published in the journal Science.

"Preservation of this extent, where you still have this flexibility and transparency, has never been seen in a dinosaur before." Feathers, hair and fossilized egg contents yes, but not truly soft tissue.

Studying the soft tissues may help answer many questions about dinosaurs. Were they cold-blooded like reptiles, warm-blooded like mammals, or somewhere in-between? How are they related to living animals?

"If we can isolate certain proteins, then perhaps we can address the issue of the physiology of the dinosaur," Schweitzer said.


306 posted on 07/03/2006 8:36:21 PM PDT by tomzz
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To: Charles H. (The_r0nin)
"What?!? That is not even close to evolutionary theory. Selection pressure has a much greater influence on rate of change; mutation rate has very little impact. A species with very few mutations but in an environment that places serious survival pressures on that species will see a greater evolutionary rate of change than a species with a high rate of mutation but very little pressure from its environment to change."

That's incorrect. Selection pressure could be from a volcano spewing ash into the air, or from a climate change, but "Selection" doesn't make any change to any species...it merely culls out those entities that have or don't have certain pre-existing genetic structures.

To actually change the genetic structure..to actually change a species, you have to have physical changes in the make-up or sequencing of the DNA itself (e.g. genetic mutations).

Without mutations, you can't have speciation. You can only have more or less of an existing population.

Nice try, though.

307 posted on 07/03/2006 8:36:29 PM PDT by Southack (Media Bias means that Castro won't be punished for Cuban war crimes against Black Angolans in Africa)
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To: tomzz

I believe that 'pack hunting' is dictated by the available prey (ie, Giganotosaurs appear to have lived in family groups, which makes sense when the prevalent herbivore was a Titanosaur - Argentinosaurus - which could grow to 10 times the size of the largest Giganotosaurus)...if the prey is smaller, solo hunting appears to be more common...with TRex its an open questions because without a doubt both ceratopsians and Hadrosaurines in the late cretaceous could get VERY big indeed, though the ration was a lot closed to 1:1....I guess we won't know for sure unless someone finds a pack of Rexes burried by a flash flood (which did in the two Giganotosaur groups that Dr. Coria found in Patagonia...)


308 posted on 07/03/2006 8:39:39 PM PDT by Al Simmons (Hillary Clinton is Stalin in a Dress)
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To: Al Simmons
Sue was about 25 years old at time of death, we have a pretty good idea as to max life spans of a TRex...the question of how often it bred and what amount of square miles could support each individual are questions that can never be answered, but I am sure that we can make some assumptions and work up a numerical range for you.....

Okay, just for the sake or discussion, let's say the T. Rex's average life span was 25 years and a heterosexual couple of T. Rex's spawned one t. Rex in their lifespans. So at minimum, there would be one new T. Rex every 25 years. At that rate, how many T. Rex's would have been born in 5 million years?

309 posted on 07/03/2006 8:40:17 PM PDT by Texas Eagle (If it wasn't for double-standards, Liberals would have no standards at all.)
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To: CarolinaGuitarman
"No, it goes to the heart of the matter. You are assuming mutations with no selection. That's nuts. It's the selection that keeps the body plan of the alligator what it is. Not the mutation rate (of which you have no idea what it is, as you made up your claims about it being slow)."

Incorrect. Again, you are unaware of the effects and interplay of mathematical probabilities on **random** mutations.

Thus, I'm not ruling out the impact of "selection." Instead, I'm factoring in the mathematical randomness of mutations.

Better vision in an alligator would not be "selected" out, for instance, contrary to your setup above. Such a random mutation would survive.

Thus, if a species remains unchanged over vast amounts of time, an answer **other** than "selection" must be present.

310 posted on 07/03/2006 8:41:24 PM PDT by Southack (Media Bias means that Castro won't be punished for Cuban war crimes against Black Angolans in Africa)
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To: tomzz
"Says you... Here's what the Reuters article had to say:"

The researchers, you know, the people who actually worked with the specimen, agree with me. You are posting the initial press release, not the actual write up from the scientists, nor the follow ups. There was no DNA found, nor intact cells, nor anything even close to *meat*. The area in question had a diameter of 3mm. Those are the facts, whether creationists want to accept it or not.

They aren't even sure if there is ANY original material in the bone.
311 posted on 07/03/2006 8:42:08 PM PDT by CarolinaGuitarman (Gas up your tanks!!)
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To: Texas Eagle

You got me. it all depends on how many you are STARTING with, and what rate of growth was average as the population expanded into new territories (using your examples the Rexes would have gone extinct pretty fast......)


312 posted on 07/03/2006 8:42:12 PM PDT by Al Simmons (Hillary Clinton is Stalin in a Dress)
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To: CarolinaGuitarman
The researchers, you know, the people who actually worked with the specimen, agree with me. You are posting the initial press release, not the actual write up from the scientists, nor the follow ups.

The initial press releases were before the hard-core evo-losers had time to get to the researchers. I view them as more accurate than whatever came later.

313 posted on 07/03/2006 8:44:23 PM PDT by tomzz
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To: demkicker
It's rather sad that you cannot or will not be more specific. Freedom of religion allows you to believe in whatever you desire, regardless of your family's beliefs.

I will not be more specific because you were rude in pinging me with an atheist ping. I would pray for you but I have bette things to do.

314 posted on 07/03/2006 8:44:58 PM PDT by OmahaFields ("What have been its fruits? ... superstition, bigotry and persecution.")
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To: balrog666

Knock it off!


315 posted on 07/03/2006 8:46:16 PM PDT by Admin Moderator
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To: Southack
Thus, if a species remains unchanged over vast amounts of time, an answer **other** than "selection" must be present.

Since no species has remained unchanged over vast amounts of time, you have just proven that there is no **other**.

316 posted on 07/03/2006 8:47:03 PM PDT by OmahaFields ("What have been its fruits? ... superstition, bigotry and persecution.")
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To: Southack
"Incorrect."

No, I am absolutely correct.

"Again, you are unaware of the effects and interplay of mathematical probabilities on **random** mutations."

And you are just blowing smoke, because the selection process is much more important than the rate of mutations.

"Thus, I'm not ruling out the impact of "selection." Instead, I'm factoring in the mathematical randomness of mutations."

You are COMPLETELY factoring out selection, and pretending that only mutations occur with nothing shaping which ones survive and which ones die off.

"Better vision in an alligator would not be "selected" out, for instance, contrary to your setup above. Such a random mutation would survive."

When did I say better vision in an alligator would be selected out? And what makes you think that it would survive automatically, without any consideration for the environment it was in?

"Thus, if a species remains unchanged over vast amounts of time, an answer **other** than "selection" must be present."

Since none of the alligator species (yes, one of those scientific words you seem to have so much trouble with) which are alive today were around 150 million years ago, your example is wrong on its face. They have not remained unchanged, but have instead speciated many times, even forming higher taxa.
317 posted on 07/03/2006 8:47:45 PM PDT by CarolinaGuitarman (Gas up your tanks!!)
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To: Southack

New body types in the fossil record are almost always associated with extinction events or geological events that produce isolation.

Breeding experiments by humans demonstrate that physical size and shape can be modified in decades rather than mellennia. The key difference between rapid and slow change is selection and changes in the conditions that determine reproductive success.

There are genomes that are more plastic than others. Dogs can be shaped rather easily, but cats have pretty much the same body shape. The answer to why this is will be found by research rather than by speculation.


318 posted on 07/03/2006 8:48:38 PM PDT by js1138 (Well I say there are some things we don't want to know! Important things!")
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To: OmahaFields
"Since no species has remained unchanged over vast amounts of time, you have just proven that there is no **other**."

Really?! In what specific, different way is an alligator that is alive today from that of its direct ancestral grandmother 20 million years ago?

319 posted on 07/03/2006 8:49:57 PM PDT by Southack (Media Bias means that Castro won't be punished for Cuban war crimes against Black Angolans in Africa)
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To: tomzz
"The initial press releases were before the hard-core evo-losers had time to get to the researchers. "

So these mythical *hard-core evo-losers* pressured the scientists into changing their stories, because of... what?

"I view them as more accurate than whatever came later."

So you view the early press release by some reporter as having more weight than what was released by the researchers themselves at the very same time, and their subsequent corrections as they did more research? You sure are eager to ignore the evidence.

BTW, the MSNBC report, while sloppy and misleading, still doesn't support your claim that meat was found. That's your invention.
320 posted on 07/03/2006 8:52:00 PM PDT by CarolinaGuitarman (Gas up your tanks!!)
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