Only the young pterosaurs flew

[nebel]

A recent Guardian article shows flying creatures with necks longer than giraffe,s. Even on the ground that is hard work to keep the head up. Bird brains are small and efficient though, even those of Monarch butterflies. ' Big birds are soarers, keep flapping to a minimum. so: The alternative theory is, that
These Creatures were more like bees, having the large reproducers in their high perched nests, supplied by herds of their family of youngsters that fitted into the flight envelope of weight/ drag and power ratios.
Love of parents, eldercare in action.

 

[river]

A recent Guardian article shows flying creatures with necks longer than giraffe,s. Even on the ground that is hard work to keep the head up. Bird brains are small and efficient though, even those of Monarch butterflies. ' Big birds are soarers, keep flapping to a minimum. so: The alternative theory is, that
These Creatures were more like bees, having the large reproducers in their high perched nests, supplied by herds of their family of youngsters that fitted into the flight envelope of weight/ drag and power ratios.
Love of parents, eldercare in action.

What do Paleontologists say ?

 

[nebel]

What do Paleontologists say ?

As far as I know, they comment only on the size, the bone structure that would have supported the flight muscles. Under present atmospheric conditions muscle powered flight is absolutely impossible at that size.
Human powered flight, Icarus stile, pedalling' allowed us to cross the Chanel, with a tailwind. Big birds are soarers. dynamic soarers like the albatrosses, or in thermals like vultures. or on slopes ###. so, awaiting new insights, my conclusion is,
only the young, the ones under 2 metre span were the flyers, able to go anywhere.
*** in my days the long distance record for soaring motorless flight was from Pennsylvania to the border of Florida , and back in one day. on a long ridge in a strong westerly wind. so:
That type of long mountain feature, with strong prevailing winds would be the limited habitat of the adults, their top of the mountains living site. They would die landing in the flats.
Freedom for the young and small only.

 

[Write4U]

Interesting question. This may be of interest:

 

[nebel]

W4y: thank you,
for my slow brain the speech is too fast. what is his point.? giraffes have a hard time even getting back on their feet, never mind achieving take off speed and lift. 30 feet stron wings to jump into the air and then start flapping like a hummingbird? think of the normal rhythm of such a loaded pendulum, a beat every 5 seconds? many birds have longer necks , in proportion to Giraffes, --- swans, flamingos. but scaled up the muscle mass required to hold them horizontally would be enormous. Were these pets penguins perhaps? underwater fliers? alternative to the alternative theory?!
I think of the 10 meter muscled flier as a peacock strutting to have offspring, -- who then, in their youth, enjoys a wide reaching feasting life. to come home to roost and grow.
Living with plenty of heights and lift, the Andes, Alps, Himalayas.

 

[nebel]

Here is another alternative: they were ground effect fliers, like the DO X or the Ekranoplan, taking off like the albatrosses on Midway Island, or dragging themselves up on cliffs edges to launch into a headwind.
Anyway, the mid sized young would have had the easier task. to wing it.

 

[river]

Birds lungs , are air sacks , which enter into the bone structure , which makes them lighter . And which gather oxygen both from inhalation and exhalation . Hence efficiency of the lung system . And the lightness of the creature .

 

[nebel]

Birds lungs , are air sacks , which enter into the bone structure , which makes them lighter . And which gather oxygen both from inhalation and exhalation . Hence efficiency of the lung system . And the lightness of the creature .

river, may be the creatures lived near rivers. for take off, gained airspeed by floating downstream fast. --really so,
, no doubt the bone structure of a 10 meter wing, 5 meter neck was light, our human, muscle powered flight attempts were studies in extreme lightness. hollow tubes, (bones) , none of the contraptions were without drag creating external wires holding the wings up on the ground , downduring lift, flight.
The weight issues is about the muscles required to hold the wings, then neck up, never mind the impossible flapping for propulsion.
They were nothing like we know that flies today. so, barring radically atmospheric condition then, you have to pick between the alternatives proposed.
The young definitely could fly, seniors did not even have too, perhaps.

 

[Write4U]

The weight issues is about the muscles required to hold the wings, then neck up, never mind the impossible flapping for propulsion.

Have we considered the air density at that time. The denser the air the greater the buoyancy.

Pterosaurs should have been too big to fly – so how did they manage it?

Pterosaurs also had a highly specialised respiratory system, similar to that of birds, with air sacs in addition to their lungs. This is a much more effective breathing system, which is important for providing the large amounts of energy needed for flight.

Pterosaurs had air sacs in their necks and trunk, and larger creatures also had them in their wings. In many cases, the air sacs invade the bones and hollow them out, making their wing bones extremely thin-walled. This is referred to as skeletal pneumaticity and is another important element contributing to large pterosaurs’ ability to fly.

Cross section of a pterosaur wing finger bone.Bayerische Staatssammlung für Paläontologie und Geologie, Munich/Elizabeth Martin-Silverston, Author provided

We know pterosaurs were the most pneumatised animals to ever live but we still don’t understand how heavy they were. For instance, estimates for the weight of Quetzalcoatlus northropi vary from 75kg to 544kg. This is because their fossils are incomplete and previous studies were based on birds, which isn’t an accurate comparison.

For example, we initially thought that pterosaurs took off by running or jumping. However, recent work has shown that they may have used their powerful forelimbs to launch themselves into the air in a similar way to vampire bats.

My research focuses on using CT scans and X-rays of pterosaur bones to create 3D models of their skeletons. These images allow me to see the internal structure of the bones, which improves our understanding of the distribution of mass and the thickness of the bones.

The goal is to determine which methods are better for determining how heavy these flying giants were. So far, we’ve found that pterosaur bones were heavier than previously thought, and that methods based on working out the volume of the body are more accurate than comparing them to modern animals. Several recent estimates put Quetzalcoatlus northropi at approximately 250kg.

Palaeontologists still have many questions about giant pterosaur flight. We don’t fully understand how they took off or what kind of flyers they were once in the air. Did they flap or soar? How long could they fly for? How did they land? In fact, some people still believe these giraffe-sized animals were too heavy to fly at all. But then what did they do with their wings? These are all questions that new techniques and fossil finds are starting to answer.

https://theconversation.com/pterosa...o-big-to-fly-so-how-did-they-manage-it-60892#

 

[nebel]

Have we considered the air density at that time. The denser the air the greater the buoyancy.

Heavier air would make the creature float, but these were not zeppelins. Thicker air favours small fliers, bumble bees, hummingbirds. please consider the Reynolds number effect,
warm thick air, like in the boundary layer of a flier, stifles speed, lift generated. . imagine having to push yourself through thicker air. Airplanes climb to fly in a thinner medium.

 

[river]

Heavier air would make the creature float, but these were not zeppelins. Thicker air favours small fliers, bumble bees, hummingbirds. please consider the Reynolds number effect,
warm thick air, like in the boundary layer of a flier, stifles speed, lift generated. . imagine having to push yourself through thicker air. Airplanes climb to fly in a thinner medium.

Not too thin .

 

[Write4U]

imagine having to push yourself through thicker air.

Penguins seems to fly quite comfortable through a thick fluid medium.

I wonder if the air-sacks actually adjusted to thinner air. Something to consider?

 

[nebel]

Not too thin .

right, there is an ultimate altitude for every wing shape, the U2 has huge wings ' The ingenuity helicopter that flew twice on mars too, and fast spinnig, with < 1% earth atmospheric density. so pterosauros had huge wings. hinged to flap.

Penguins seems to fly quite comfortable through a thick fluid medium.

Yeah, they are propelling themselves through water. The denser the fluid, the smaller the wings. Think of the tuna, 75 km/h, with a small tail but huge, delicious muscles.
wings of pterosaur adults were huge. indicating flight in a rare medium. thank you!

 

[Write4U]

wings of pterosaur adults were huge. indicating flight in a rare medium. thank you

LOL, nobody said they were good swimmers......

 

[nebel]

LOL, nobody said they were good swimmers.....

but penguins with small "wings" are. so the alternative theory, that the atmosphere during pterosaurs time was thicker is not valid. For larger than human beings to try to fly with small flapping wings is no Laughing OL matter; there are some hilarious clips of attempts from ~ 120 years ago though.

 

[Write4U]

but penguins with small "wings" are. so the alternative theory, that the atmosphere during pterosaurs time was thicker is not valid. For larger than human beings to try to fly with small flapping wings is no Laughing OL matter; there are some hilarious clips of attempts from ~ 120 years ago though.

LOL, I'm not disagreeing with you...

 

[nebel]

I'm not disagreeing

I am glad we have agreement. There is an enigma, In the evolutionary process, why would a flier grow to that size, when it could not fly, by today's standards? was it it's size that made their branch whither on the tree of ancestry?
quote: "what did they do with their wings?"
used them as fake umbrellas to catch the prey resting, hiding in their "protective" shade.

 

[Write4U]

was it it's size that made their branch whither on the tree of ancestry

I would guess so. Apparently the oxygen rich environment helped in extraordinary growth. Let's not forget that their reign lasted several hundred million years. But when the air stabilized at a lower oxygen level, their size became a burden and they became extinct from their sheer size.

I see that that as a possible scenario. If combined with a long gestation and or fertility cycle they may just have faded away slowly one by one.

This can be seen today with our remaining giants who are endangered species and slowly are reducing in numbers.

It is one of mathematical cruelties of natural selection. Sometimes you can outgrow your own survival mechanisms.

 

[nebel]

Here is another example of the mature, breeding individuals of a species, becoming too big to fly. only the young levitate.



Moth too big to fly found at construction site
Cheryl Santa Maria
Digital Reporter
Monday, May 17th 2021, 2:56 pm - The rarel-seen moth turned up at a construction site near a rainforest.


A gigantic moth that's too big to fly and rarely seen by humans has been turned up at a school building site in Australia, several outlets report.

Found in wooded areas of Australia and New Zealand, the giant wood moth (Endoxyla cinereus) is the world's largest moth species. Females are twice the size of males, weighing up to 30 grams and boasting a wingspan up to 25 centimetres.

They're rarely seen by humans because adult giant wood moths cannot feed and only live for a few days, reaching their full size just before mating and dying soon after, the Australian Museum says.

 

[nebel]

https://theconversation.com/pterosa...o-big-to-fly-so-how-did-they-manage-it-60892#

Launching techniques are varied. The greatest benefit is the wind gradient., that would give you instant air speed when jumping up into the wind, like that. Better yet, when jumping into wind that is rising on a slope. .
having experienced both, I doubt a creature that size would have the muscle power/mass ratio to manage these forces, even just to hold the wings level , never mind sustain flapping propulsion to keep airborne , Think of the natural resonance of a 5 meter pendulum too.
Then there is gravity assist, like bats, falling from a ceiling of sufficient heights (the Wright brothers used a falling weight & rope method)
Landings would be hard on those fragile light bones, of the older grown specimen.
Paul Mac Ceady, of human powered flight fame, tried to replicate a flying dinosaur of modest size, 3 meter span perhaps, but, lacking a bird brain, with a predictable outcome. so,
the cranes are back in Ireland, but that seems to be the size of it, so,
really huge flyers , like the moth above, when grown, come home to roost, reproduce and rest for their good. so, perhaps

the huge fly only when they're small fry.