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# What drove bird evolution?

Author Topic:   What drove bird evolution?
redwolf
Member (Idle past 5104 days)
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From: alexandria va usa
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 Message 121 of 145 (125370) 07-18-2004 1:40 AM

You'd have to do a volumetric study to get a realistic weight estimate for the seismosaur's neck but, visually, you can line up three to five 10,000 lb elephants alongside the guy's neck and figure 40K lbs and you're probably ballpark. Having the cog of the neck 15' from the shoulders would also be conservative ballpark. That would be 600,000 foot pounds of torque.

When I first noticed that, I tried to come up with something to compare it to to try to visualize it. I spoke with the people who service tanks and tank-tow vehicles at Aberdeen, i.e. how much torque is there on anything on a tank or tank-tow vehicle, and the answer was around 600 - 1000 foot pounds. I asked people at shipyards, how much torque was there on any sort of a nut which held a propeller on a large ship; couple thousand foot pounds...

The only thing I could come up with with torque in the hundreds of thousands of foot pounds like that would be the combined total torque of all engines of a very large ship. For instance, max total horsepower for an Iowa class battleship, all four engines, is given as about 200,000 hp. If you use the normal formula for torque, i.e. (Horsepower * 5252) / RPM and assume maximum HP on one of those ngines is around 2500 rpm, which is a pure guess since I've not found figures for it, you'd be looking at 420160 foot pounds. That would be the maximum combined total torque of all four engines of an Iowa class battleship. That would be the torque needed to drive one of those ships through the water at a bit better than 30 knots.

Now, the seismosaur looks big standing next to people, but not standing next to an Iowa class battleship. Having that kind of a torque load hanging off his shoulders 24/7 is not a ticket for success in life, or for dominating the world for tens of millions of years, as is claimed.

 Replies to this message: Message 123 by arachnophilia, posted 07-18-2004 2:27 AM redwolf has replied Message 128 by crashfrog, posted 07-18-2004 10:18 AM redwolf has replied Message 142 by Cthulhu, posted 11-10-2004 4:02 PM redwolf has not replied

arachnophilia
Member (Idle past 656 days)
Posts: 9069
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 Message 122 of 145 (125372) 07-18-2004 2:10 AM Reply to: Message 105 by redwolf07-17-2004 2:44 PM

they're out to get your money.

 There is a petroglyph in Natural Bridges National Monument that bears a startling resemblance to dinosaur, specifically a Brontosaurus, with a long tail and neck, small head and all." (Prehistoric Indians, Barnes and Pendleton, 1995, p.201)

as i believe someone pointed out, there is no such dinosaur. the brontosaurus was an apatasaurus who's head somehow got changed with that of a camarasaurus.

so, let's begin the lecture on dinosaur physiology, shall we?

 There were two basic types of sauropods, i.e. brachiosaurids and the diplidocids. Simply from the bone structure, the former appear to have held their necks and heads upwards, the later outwards.

it's not so much bone structure as balance. but either way, no dinosaur dragged its tail, as depicted in the petroglyph. tails, in the dinosaur world, were used as counter weights, to balance the animal. the depictions of dinosaurs with their tails on the ground are very dated, and the simple fact that image seems to show a dinosaur with its tail on the ground (below ground?) indicates that if a person made it, they hadn't seen a real sauropod at any point.

 In our gravity, of course, neither would be possible. A sauropod holding his head upward would be impossible because of the blood pressure requirements to get blood to a brain 40' above its heart

hearts. plural. they think brachiosaurus had about 8 of them, and all pretty large. this was an animal adapted to reaching the highest branches. and either way, the blood pressure study has been done, and it's not problem.

 holding his neck outwards would be impossible because it would involve hundreds of thousands of foot pounds of torque.

that's what tails are for. they counter balance. it's also one reason sauropods have small heads (the other reason may be found above, if you think about it). sauropods that hold their heads outward tend to have high dorsal vertbrae, where thick muscle (and even tendons and bone) attach to make a sauropod essentially a miniature golden gate bridge.

but, i guess the millions of foot pounds of torque on that rule that out in today's gravity too. maybe gravity is different in california?

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 Replies to this message: Message 124 by redwolf, posted 07-18-2004 8:04 AM arachnophilia has replied Message 139 by Dr Jack, posted 07-19-2004 5:48 AM arachnophilia has replied

arachnophilia
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 Message 123 of 145 (125376) 07-18-2004 2:27 AM Reply to: Message 121 by redwolf07-18-2004 1:40 AM

i believe you already have a thread for this, but let's look at a better resolution picture of a REAL seismosaur skeleton.

how high would say those dorsal spins are? 4 feet? 5?

here's an illustration of its internal organs, but you can see what the skeleton looks like better

it doesn't need to hold up a lot of weight with its neck. just the mass of its head and neck. notice how the vertbrae just fore of the hips are turned? i don't know exactly where you're getting your figures, but the neck itself doesn't actually matter. the neck is counter balanced against the tail, so that the net force downward is over the hip. the way the bones are deforemed near the hip is evidence of that.

edited to fix page width - The Queen

This message has been edited by AdminAsgara, 07-18-2004 01:29 AM

 This message is a reply to: Message 121 by redwolf, posted 07-18-2004 1:40 AM redwolf has replied

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redwolf
Member (Idle past 5104 days)
Posts: 185
From: alexandria va usa
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 Message 124 of 145 (125419) 07-18-2004 8:04 AM Reply to: Message 122 by arachnophilia07-18-2004 2:10 AM

quote:

hearts. plural. they think brachiosaurus had about 8 of them, and all pretty large. this was an animal adapted to reaching the highest branches. and either way, the blood pressure study has been done, and it's not problem.

I'm not aware of any animal with more than one heart and I'm not aware of any scientific literature backing that sort of claim. Conversely, statements to the effect that there would be an insurmountable problem with sauropods holding their heads high are easy to find in real scientific literature.

 This message is a reply to: Message 122 by arachnophilia, posted 07-18-2004 2:10 AM arachnophilia has replied

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redwolf
Member (Idle past 5104 days)
Posts: 185
From: alexandria va usa
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 Message 125 of 145 (125420) 07-18-2004 8:08 AM Reply to: Message 123 by arachnophilia07-18-2004 2:27 AM

> the neck is counter balanced against the tail

That's right. The neck and the tail would both be lying flat on the ground in our present gravity...

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arachnophilia
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 Message 126 of 145 (125421) 07-18-2004 8:14 AM Reply to: Message 124 by redwolf07-18-2004 8:04 AM

 I'm not aware of any animal with more than one heart and I'm not aware of any scientific literature backing that sort of claim. Conversely, statements to the effect that there would be an insurmountable problem with sauropods holding their heads high are easy to find in real scientific literature.

you just haven't done your reading. here's a hint, get off the internet. i remember very distinctly when the issue of the cardiopulmonary system of a brachiosaurus was dealt with. i do believe they even had fossil evidence to support it.

and no, you wouldn't be aware of any creatures today with more than one heart. not many creatures are specifically evolved to grow so high.

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arachnophilia
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Posts: 9069
From: god's waiting room
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 Message 127 of 145 (125422) 07-18-2004 8:16 AM Reply to: Message 125 by redwolf07-18-2004 8:08 AM

 > the neck is counter balanced against the tailThat's right. The neck and the tail would both be lying flat on the ground in our present gravity...

i think you don't understand gravity. suspension bridges work just fine, and sauropods are built like moving suspension bridges. they don't even have to hold up that much wieght.

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crashfrog
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 Message 128 of 145 (125435) 07-18-2004 10:18 AM Reply to: Message 121 by redwolf07-18-2004 1:40 AM

 That would be the maximum combined total torque of all four engines of an Iowa class battleship.

Here's that crane again, handling torque loads hundreds of thousands of times greater than the sauropod:

Can you show me, on that crane, where the thousands of Iowa-class battleship engines are located? Because I can't seem to find them, but your argument insists that they must be there.

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redwolf
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 Message 129 of 145 (125459) 07-18-2004 1:36 PM Reply to: Message 126 by arachnophilia07-18-2004 8:14 AM

quote:

I'm not aware of any animal with more than one heart and I'm not aware of any scientific literature backing that sort of claim. Conversely, statements to the effect that there would be an insurmountable problem with sauropods holding their heads high are easy to find in real scientific literature.

you just haven't done your reading. here's a hint, get off the internet. i remember very distinctly when the issue of the cardiopulmonary system of a brachiosaurus was dealt with. i do believe they even had fossil evidence to support it.

I was trying to be polite the first time. If you're going to stick with this sort of ignorant bullshit, there's no real need for politeness.

There is no animal with more than one heart and no reason to believe there ever would have been. That would require that dinosaurs had been a totally separate creation from all other animals, which NOBODY believes, evolutionists, creationists, or anybody else other possibly than the people who write the Marvel comic books.

Moreover, a number of totally competent scientists have flatly stated that a sauropod dinosaur could not hold his head high due to the problems of the blood pressure which would be required to do so (in our present gravity).

Christopher McGowan (DINOSAURS, SPITFIRES, & SEA DRAGONS) goes into this in detail (pages 101 - 120). He mentions the fact that a giraffe's blood pressure, at 200 - 300 mm Hg, far higher than that of any other animal, would probably rupture the vascular system of any other animal, and is maintained by thick arterial walls and by a very tight skin which apparently acts like a jet pilot's pressure suit. A giraffe's head might reach to 20'. How a sauropod might have gotten blood to its brain at 50' or 60' is the real question.

Two articles which mention this problem appeared in the 12/91 issue of Natural History. In "Sauropods and Gravity", Harvey B. Lillywhite of Univ. Fla., Gainesville, notes:

quote:

"...in a Barosaurus with its head held high, the heart had to work against a gravitational pressure of about 590 mm of mercury (Hg). In order for the heart to eject blood into the arteries of the neck, its pressure must exceed that of the blood pushing against the opposite side of the outflow valve. Moreover, some additional pressure would have been needed to overcome the resistance of smaller vessels within the head for blood flow to meet the requirements for brain and facial tissues. Therefore, hearts of Barosaurus must have generated pressures at least six times greater than those of humans and three to four times greater than those of giraffes."

In the same issue of Natural History, Peter Dodson ("Lifestyles of the Huge and Famous"), mentions that:

quote:

"Brachiosaurus was built like a giraffe and may have fed like one. But most sauropods were built quite differently. At the base of the neck, a sauropod's vertebral spines unlike those of a giraffe, were weak and low and did not provide leverage for the muscles required to elevate the head in a high position. Furthermore, the blood pressure required to pump blood up to the brain, thirty or more feet in the air, would have placed extraordinary demands on the heart (see opposite page) [Lillywhite's article] and would seemingly have placed the animal at severe risk of a stroke, an aneurysm, or some other circulatory disaster. If sauropods fed with the neck extended just a little above heart level, say from ground level up to fifteen feet, the blood pressure required would have been far more reasonable."

 This message is a reply to: Message 126 by arachnophilia, posted 07-18-2004 8:14 AM arachnophilia has replied

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redwolf
Member (Idle past 5104 days)
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From: alexandria va usa
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 Message 130 of 145 (125460) 07-18-2004 1:37 PM Reply to: Message 128 by crashfrog07-18-2004 10:18 AM

>Here's that crane again...

One word: irrelevant.

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jar
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 Message 131 of 145 (125461) 07-18-2004 1:46 PM Reply to: Message 129 by redwolf07-18-2004 1:36 PM

One word: irrelevant.

Aslan is not a Tame Lion

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crashfrog
Member (Idle past 780 days)
Posts: 19762
From: Silver Spring, MD
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 Message 132 of 145 (125481) 07-18-2004 4:24 PM Reply to: Message 130 by redwolf07-18-2004 1:37 PM

 One word: irrelevant.

You mean, your claim about sauropod torque loads and Iowa-class battleship engines? Yes, given that the sauropod neck handled torque loads in the exact same way the modern skycrane does, I would indeed say your claim was irrelevant. That was the purpose of my example.

But it's good to see you agree. Now can we drop this ridiculous gravity fiction?

 This message is a reply to: Message 130 by redwolf, posted 07-18-2004 1:37 PM redwolf has not replied

redwolf
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Posts: 185
From: alexandria va usa
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 Message 133 of 145 (125490) 07-18-2004 4:59 PM

crane irrelevant
The crane is irrelevant because it is supported by cables anchored at a point substantially higher than the body of the crane itself, and no animal has a neck which is built like that.

 Replies to this message: Message 134 by crashfrog, posted 07-18-2004 5:35 PM redwolf has not replied Message 137 by arachnophilia, posted 07-18-2004 6:28 PM redwolf has not replied

crashfrog
Member (Idle past 780 days)
Posts: 19762
From: Silver Spring, MD
Joined: 03-20-2003

 Message 134 of 145 (125492) 07-18-2004 5:35 PM Reply to: Message 133 by redwolf07-18-2004 4:59 PM

 The crane is irrelevant because it is supported by cables anchored at a point substantially higher than the body of the crane itself, and no animal has a neck which is built like that.

An assertion contradicted by a number of skeletons shown to you so far. The sauropod's arched back provides a more than high enough anchor point for the torque loads experienced by the neck, and the tail provides the same counterbalance that the skycrane uses.

Boring, RW. If you can't do anything but repeat already-rebuked assertions, why do you even post here?

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NosyNed
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 Message 135 of 145 (125493) 07-18-2004 5:49 PM Reply to: Message 134 by crashfrog07-18-2004 5:35 PM

back up?
 The sauropod's arched back provides a more than high enough anchor point for the torque loads experienced by the neck, and the tail provides the same counterbalance that the skycrane uses.

Somewhere I would think someone has done the numbers on this. Can you back this up with those numbers?

 This message is a reply to: Message 134 by crashfrog, posted 07-18-2004 5:35 PM crashfrog has not replied

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