have you considered other possible means to increase atmospheric pressure at sea level - or is oxygen the only factor?

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http://en.wikipedia.org/wiki/Sauropoda

Hi Christine,

Thanks for the information. The giraffes have biological means to cope with higher blood pressure. A Sauropod's neck is however significantly longer, say 18 meters (60 ft) compared to a giraffe which is 5.5 meters tall, which would increase the pressure problem by a factor of three.

The question of mass and structural support is interesting. I would be interested to see a scientific paper that addressed that issue. The Argentinosaurus has 10 times more massive than a Savannah Elephant.

From Wikipedia.

One, somebody tell "Chris Yukna" that Mr. Paragragh is his friend.

Don't look Gillian. The third link is a badly written 10th grade science paper worth about a "D-" for structure and maybe a "C" for content for hitting on most points. Run through a spell checker. Though if this was a 6th grader I'd go higher.

If this person is older then it's a classic example of somebody remembering their high school science then commenting on that same science 15 to 20 years later when they matured, without following up on or getting current with present evidence.

ATM'ers and Creationists/Young Earthers are famous for this. Everybody knows science grinds to a halt once you leave high school to allow you to mature and then come back and tell them it's wrong.

So the first mega-paragragh goes casting doubts on "giant insects" by mixing the terminologies of eupteryds and scorpions. And taking analogies literally. Or he's just confused. The so called "sea scorpions" were aquatic. 100 ton whales are too. The "land prints" were a low tidal flat. The largest members of the Carnivora, (dogs, foxes, bears, cats, seals, sealions) the pinnipeds, leave footprints on land as well. Going to say seals shouldn't exit, just look at cats?

Pterosaurs are reptiles so no they are not dinosaurs. That's a whole other evolutionary line. They DO have keel bones so the author is WRONG on that one, flat out.

Birds, descendants of theropods do have keel bones as did a lot of non-flying theropods. A keel bone isn't nessarely a flight adaptation. It's where your pectorials hook up. Look at their own dragonfly example. No keelbone there.

The old "half wings won't let you fly" saw was settled in the mid-eighties. Won't even go there.

The whole thing is based on ignorance of what happens to animals that have a lot of room, due to mega-continents. Animals with lots of space and food will get huge. Over time! Lots of time!

There is a profound ignorance of time here. In a million years humans will have approximately 33,000 generations. Insects in a warm stable enviroment, in the same time frame, will kick out 2 million generations, or more, each better adapted than the one before!

Let's disect this bit shall we?

Well some people tried to raise them in greenhouses with an atmosphere of 35% oxygen. The results were disappointing: some slight increase in size.

This right up there with those wondering why nothing has evovled in peanut butter since we've been making peanut butter. No concept of deep time. I'm amazed they saw a result within their attention span. I suspect prevarication. Really. Think about that set up. If not a lie, this should be looked at by actual scientists.

However, there still is a problem with these airborne dragonflies . If enriched Oxygen levels allow increased energy expenditure then there would be an augmentation of heat. Thus the flies would burn up.

So I take two engines, one designed to work at sea level (then) and then one designed to operate at 30,000 feet (now). If I put the high altitude fuel in the low altitude engine, yes I'm going to burn that engine out.

One minor note of discord, some studies seem to indicate that high levels of oxygen can impede the growth of plants

By which he means modern plants.


This is a bad book report.

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This is a link to a blog for pterosaur specialists and aficionados.

It does appear pterosaur mass is controversial and not resolved.

http://darrennaish.blogspot.com/2006...storks_03.html

Great Physical Mass of Brachiosaurs and Leg Structure

Declarative statement. Also wrong when applied in this manner. Aircraft are made of steal and aluminum. If I measured an F-14's dimensions and use their logic, I come up with about 300 tons. I could be wrong.

Not allowing for lungs, pneumatic bone and digestive system which is mainly full of gas.


Or 5 indricotheres. 10 to 20 ton rhinos that lived in Asia 30 million years ago.

Pneumatic bones! Look up pnuematic bones! There were no borophagic dinosaurs! Why? Because almost no dinosaurs filled their bones with fat and marrow!


What kind of a statement is this? Does he see horses getting their legs fixed? Good Lord, even bunny rabbits die when they get a broken leg. Who wrote this? A ten year old?

Do you people know what the terrestrial version of blood in the water is?

A limp.

A predator's eye is automatically drawn to a limp. You move differently than the herd and this indicates you are easier to run down than your non-limping brethren.



William, just to let you know, none of my above posts mean I wouldn't give you ice water on a hot day or that I wouldn't go fishing with you. It just means I wouldn't let you teach paleontology that's all.

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In your rush to call everyone "entrenched" or closed-minded or "limited" you fail to note that the "limit" here has a very natural boundary: that point at which the evidence stops. - JayUtah

Science fiction was never meant to be an educational tool. - Editor Amazing Tales

Thanks Grant, I'll go look. He uses metric units I take it?
Metric, people! Metric is easy, all you have to do is move the little dot around!

Yeah. I'm also noticing that the same 'facts' are used to support a variety of ATM arguments. For example, the link I gave earlier, is a debunking of Ted Holden. Holden's...Velikovsky, and his maaaad planetary orbits. Next up, a proposal linking dinosaurs to UFOs...

p.s Good rebuttal BigDon. Especially the part about lots of time. Thanks, that was interesting. Peanut butter! I loved that...

Yes, liked your posts, BigDon.

Ah, I was wondering if this thread fit in with the catastrophism/Velikovsky/Electric Universe stuff, or if it was going down a different ATM path. That makes it clearer. I know I've read about Holden before, but I'd managed to forget about him.

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William's 3rd source was surprised that ferns could be 3m or 4m high in the carboniferous, and one of the posters above expressed a similar thing.

Actually there are 100s of species of tree fern growing today, widespread in rain forest climates, and one or two other places.
http://en.wikipedia.org/wiki/Cyathea_brownii is said to be the tallest species, but
http://en.wikipedia.org/wiki/Cyathea_medullaris is similar. Both are said to grow up to 20m tall.

Ted Holden!! a Legend across on Talk Origins lol.

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He does. Be warned that it's now (ulp) 19 years old, so you're not going to see a treatment of the recently discovered giants. But basic physics hasn't changed, and the size of an Apatosaurus hasn't changed, and scaling laws haven't changed, so there's much of biophysical interest in there. Alexander, for instance, looks at the difference in load-bearing behaviour of sand and clay, and shows that a domestic cow will sink a lot farther into sand than an Apatosaurus, but an Apatosaurus will sink further than a cow in clay. Who'd have guessed?
In essence, it's the same message we had on the pterosaurs thread: biophysics constrains the options of giant animals; it doesn't render them impossible.

You can pick up a cheap second-hand copy pretty easily.

Grant Hutchison

When I was younger it was the apparent impossibility of eating enough plant material through those tiny heads to keep the sauropods alive.

One does come back to the existence of plentiful evidence these animals not only survived, but thrived. There are no logical paradoxes, just insufficient additional factual detail and interpretation to explain everything at this time.

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If they can get you asking the wrong questions, they don't have to worry about the answers.

Praed, did you actually see that youtube video? There is one if you need to slap your forehead and groan at something.

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In your rush to call everyone "entrenched" or closed-minded or "limited" you fail to note that the "limit" here has a very natural boundary: that point at which the evidence stops. - JayUtah

Science fiction was never meant to be an educational tool. - Editor Amazing Tales

There is the question of how creamy peanut butter could evolve into chunky peanut butter.

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If they can get you asking the wrong questions, they don't have to worry about the answers.

Reverse entropy. Peanut butter, chunky, violates thermodynamics, too.

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I KNEW chunky peanut butter was a crime against nature!

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In your rush to call everyone "entrenched" or closed-minded or "limited" you fail to note that the "limit" here has a very natural boundary: that point at which the evidence stops. - JayUtah

Science fiction was never meant to be an educational tool. - Editor Amazing Tales

Excellent. 19yrs old is fine. I'm on the case...

I need cheering up; so slapping my head sounds good. Post the link if you can. Ta.

[off-topic] I don't know ... I think 19yrs old is a bit young - they move too fast, and we have almost nothing in common ... [/off-topic]

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Shoot, anybody under the age of 25 reminds me so much of my own kids it's a nonstarter at the get go.

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In your rush to call everyone "entrenched" or closed-minded or "limited" you fail to note that the "limit" here has a very natural boundary: that point at which the evidence stops. - JayUtah

Science fiction was never meant to be an educational tool. - Editor Amazing Tales

I know that feeling ...

funny thing is, I can remember the time when I thought anyone over 25 was a "living fossil" ...

>cough<
the reason I asked is that, while oxygen is vital for keeping our blood the right shade of red, etc, it's only one (and not the major) component of the atmosphere ... other bits of it have also shown signs of greater or lesser partial pressure at times ... and there are hints that the lower air column has also varied in height ... all of which suggests that 1 bar might not have always been the standard ...


The mention of 35% O2, and giant insects, rang a bell - is there some confusion here between the Cretaceous ...
and the Carboniferous?

- Abstract
Berner et al, 2003; Phanerozoic Atmospheric Oxygen; Annual Review of Earth and Planetary Sciences; Vol. 31: 105-134 (Volume publication date May 2003)

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The story of high oxygen in the Cretaceous dates back to the 80s, with the work on amber bubbles which was subsequently discredited. It then revived with Bergman's COPSE model. But Berner's more recent GEOCARBSULF model (770kB pdf) suggests low levels of oxygen in the Cretaceous: down to the equivalent of 12% of our current atmospheric pressure, then rising to 18% towards the end.

Grant Hutchison

thanks for the link, Grant, though when I last studied it (the subject, not this paper), the O2 low point was in the Triassic, ~100Myr ealier ...

oh yes - it's in the abstract:

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GEOCARBSULF's low (that 12% I mentioned) is actually in the early Jurassic. I garbled the timing in my previous post, by somehow mentally conflating the Jurassic and Cretaceous I'm not doing well today.
Oxygen oscillates around ~18% during the Cretaceous.

Grant Hutchison

That's why dinosaurs were big; they needed bigger lungs...

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The first place I recall encountering the particulars of the square-cube law as related to dinosaurs was in Robert Bakker's book The Dinosaur Herises. As he pointed out, the total load support includes not only the bone itself but the various ligaments and other structures in the leg.

And I saw in this biweekly's Science News that a skeleton providing evidence of an avian breathing system in dinos has been found in So. America.

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What about a super dense atmosphere? Not just increased Oxygen, as was being discussed about the insects, but a denser concentration of all atmospheric gas. Would a super dense atmosphere have been able to prop up their huge weights through buoyancy?

It was a highly active volcanic time, so it would seem the possibility is there.

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Super dense atmosphere would give the same pressure all around the bug, so wouldn't produce any bouancy.

You need changes of density for that.

Like how wood is more dense than air but (generally) less dense than water.

So it floats on water, but doesn't rise into the air.

The air might be really really dense, but it would only help that wood "float" if it were more dense than that wood.


(Dense air might help wings work better, but that's a different thing...)

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ahh well, what's a few million decades between friends?

The important thing is that we both seem to support a finding of substantially less than 35% (partial pressure) O2 in the Mesozoic ... and that the author seems to have confused the Palaeozoic Carboniferous (high O2; biggest bugs) with the Mesozoic Cretaceous (mostly high sea levels, high temps, biggest critters) ...

easy enough to do, I guess - the two longest-running periods in the Phanerozoic; roughly one galactic orbit apart ... the sort of thing that suggests patterns ...


yes, but it was one of the issues/problems raised by the OP ...

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Do you know what I find intriguing? The 5 to 10 million year spans of time between major extinguisons (I'm drunk folks, going to go vote the President pretty soon.) Like the T/K thing. You have plants evolved to co-exist with major plant munching dinosaurs and no dinosaurs!

So after the Very Bad Thing happened (to the dinosaurs) What happens ? A pole to pole forest! How rockin' is that?

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In your rush to call everyone "entrenched" or closed-minded or "limited" you fail to note that the "limit" here has a very natural boundary: that point at which the evidence stops. - JayUtah

Science fiction was never meant to be an educational tool. - Editor Amazing Tales