"Required" by who, your cockamamie scientific "laws" or by creatures who actually flew?
Swordmaker: "That is what the cube/square law is about.
Yes, you can increase the size of the wing, but then it WON'T BE THE SAME STRUCTURE AS A MODERN EAGLE!
The shape of the bird would be different.
As one increases the sail area, the muscle size must increase by the cube of the square area of the wing."
First of all, your "cube/square law" must be considered as baloney-to-the-max, since your presentation of it consists 100% of assertion-insult followed by more assertion-insults.
There's no "proof" in anything you've said.
Second, there's no scientific "law" which says the avian wing-load of 5 lbs. per square foot stops functioning beyond 30 pounds, or 50 pounds.
Since it's basically the same limit as hang-gliders and ultra-light aircraft, there's no upper weight limit.
Yes, of course, I "get" your idea that a bird's (or pterosaur's) body size might grow faster than its wing area.
To make your argument for you, you claim that:
- if a 25 pound bird needs 5 square-feet of wing-lift area, and accomplishes this with wings 10 feet long and half a foot wide, and
- if it needed to grow wings 15 feet long by one foot wide, to lift a higher body-weight of 75 lbs -- you claim that
- by the time its wings grew from 10 to 15 feet, its body-weight must absolutely necessarily, according to some mythological "cube/square law" you fanaticize, the bird's weight must be more than 75 lbs.
Sure I "get" that, but its rubbish for at least the following reasons:
- You have not proof that your alleged "cube/square law" effectively limits sizes of any animals, and fossil evidence shows it does not.
- Your "cube/square law" cannot predict what the weight (in the example above) of a 15 foot wing-span bird must be.
- All actual scientific estimates of prehistoric flying-creature weights fall within the 5 lbs. per square-foot of wing-load limit.
- You cannot "prove" any of those estimates wrong.
I therefore conclude that you folks are simply advocates of an anti-science agenda, motivated more by theology than any serious interest in finding natural explanations for natural processes.
Swordmaker: "The teratorn fossil structure was essentially a scaled up eagle without oversized wings.
You can theorize oversized wings all you want but they weren't there and neither were the muscles"
In fact, your claim here notwithstanding: large teratorns like Argentavis are the very definition of "scaled up" and "oversized wings".
And in all cases, the scientific estimates of wing-size versus body-weight obey the 5 lbs. per spare-foot of wing rule.
So, why and how you fanaticize that your alleged "cube/square rule" overrules the simple wing-load is beyond rational comprehension.
Swordmaker: "Nor were the muscles in the dinosaurs capable of swinging or lifting a cantilevered neck using bone and sinew as the structural materials. . . the engineering math simply doesn't work."
Sure, I "get" that this was a problem from the beginning, over 100 years ago.
That's why, many years ago, sauropods were often pictured mostly under water.
And I'm still not convinced there's anything particularly wrong with that -- consider nostrils on top.
Today they are always portrayed out-of-water, with head and tail counterbalanced parallel to the ground, not reaching (much less rearing) up for high branches.
Bottom line: there's no evidence, certainly none presented on this thread, which "proves" that your alleged "cube/square law" magically limits the sizes of prehistoric beasts to that of modern elephants.
Swordmaker: "Nor were the muscles in the dinosaurs capable of swinging or lifting a cantilevered neck using bone and sinew as the structural materials. . . the engineering math simply doesn't work."
Since your math doesn't work, obviously your math is wrong.
Time for you to reexamine your ridiculous assumptions.
Out of time, must run...