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.
Thank you. (re: Bumble Bees)
I'm guessing it flew. It is like a mathematical equation where you have more than one variable. In this case lots of variables, since we do not have a complete creature to test fly and we do not know what the environment was like when it lived.
But the range of possibilities are in two categories:
1. things we don't yet know (or haven't thought about) regarding the animal.
2. Things we don't yet know (or haven't thought about) regarding the environment in which it lived.
The solution to this puzzle could be in one or both categories.
Regarding the Bronto...I mean, Apatosaurus, there is a lot of speculation going on regarding all sorts of things - not just tendons, but blood pressure variances, etc. There's more to it than the pictures in schoolbooks, and people need to be educated about such things.
From Wikipedia:"MacCready also developed, for the Smithsonian Institution, a half-scale replica of the giant pterosaur, Quetzalcoatlus northropi. The model had a wingspan of 5.5 meters (18 feet) and featured a complex, computerized control system, just as the full-size pterosaur relied on its neuromuscular system to make constant adjustments in flight."
Here is the link to a short video of its flight:
http://ovirc4.free.fr/Films/maccready.mpg
I believe it, but it only proves aerodynamics.
First, it was half scale, and size matters. Second, it was not made of living material.
As I understand it, even with hollow bones, etc., modern birds cannot fly once a maximum weight of around 35 lbs is reached. At that point, it takes more than a pound of muscle/bone/feather/membrane to produce a pound of lift. So the farther from 35 lbs you get, the more impractical it becomes.
I wonder if there was any mylar and carbon fiber in the half scale model? ;)
"Maybe you need to check out the definition of "bash":
To criticize harshly; To engage in harsh, accusatory criticism. "
Ahhh, BASH. I didn't get that. Does that include a self-righteous poster who starts a flame by telling someone that they must have been hitting the bottle mighty early this morning? You must have mistaken me for one of your flock. I don't drink.
"I think we're done here."
I'll let you know when I'm done. It would seem that the bashing has been attempted by you, (not that you are very good at it) and now you would really like someone to feel sorry for you. I'll do that. I feel sorry that self-righteous people like you can't find happiness in life unless they are sure all the others around them are going to hell.
Still no facts about T-Rex?
Ok, we're done. Have a nice day, Dem.
And how is that relevent to the assertion that "scientists" said bee flight is "impossible"?
It sounds a bit like saying evolution or abiogenesis is impossible because parts are still a mystery.
I was making the argument that just because we can't figure out how nature works in all instances doesn't mean that it doesn't....(it was a reply to the 'Pterosaur's were too big too fly' argument that I seem to recall someone - not sure who anymore - made...)
Please post the actual calculations or a link.
LOL. Taking up where I left off? I think SH gets his concept of mutations from Hollywood. If you can't see it at 20 paces, it doesn't exist.
Possibly not a bad policy for examining crocks and gators.
OK, but you'll just deny the math or the link or the context. Evolutionists are *never* persuaded by math.
But since you asked... Requested Math That Proves T Rex Birth Rate Too Low For Evolutionary Explanation
This has got to be one of the silliest things I've ever heard of. How anyone can take (or pretend to take) such ideas and the people who spread them seriously is beyond me.
For example, there are Burgess Shale trilobites with big nasty bites chomped off. There are no bones, much less people, in the Cambrian. No fish, no reptiles, no birds, no bones at all. None.
A minority opinion. AFAIK, only Jews, Christians, Muslims, and atheists deny animals having spirits. Hindus, Buddhists, and animists all assert that they do.
Is it possible for a chihuahua and a great Dane to mate?
What "soft tissue"?
If you want some math that employs raw chance and has at least some relevance, take a look at the cash flow at a casino. Every wager is stochastic, and yet the trend is inexorable.
It is bad form to talk about other Freepers behind their backs.
And you are confusing Southack's guess with a fact.
Ironically, your example of casino math only conveys a single trend (i.e. the house eventually wins), failing to yield enough properly sequenced data to code a life form (e.g. red casino chips being DNA A, green casino chips being DNA G, black casino chips being DNA T, blue casino chips being DNA C) or otherwise convey any meaningful amount of information.
In fact, the sum of all casinos playing colored chips over all of history will not, statistically, properly sequence (by chance) the DNA of even the most simple life form.
Not even once.
"Mud Flaps, Arizona"
LOL!
google t-rex and soft tissue.
It is a minority opinion that Jesus is God in the flesh. There is even a movie about the "minority opinion".
Sometimes the minority is right.
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