Too big to fly? A new YouTube video

The channel Animalogic produced the linked video
posing the question of Quetzalcoatlus (Fig 1) flight. Comments follow. Long-time readers will be familiar with these facts, arguments and insights.

@7:27 adult pterosaurs range down past the size of a sparrow down to the size of a bee hummingbird, the smallest living bird. There are no ‘huge gaps’ in our knowledge of pterosaur interrelationships according to the large pterosaur tree, a cladogram with an unsurpassed 266 taxa. All taxa blend together as in microevolution. At the genesis of new clades phylogenetic miniaturization is common, in which smaller pterosaurs become precocious in a series of generations, laying eggs while their bones still showed juvenile traits. Speaking of which, hatchlings had adult proportions, a trait inherited from their deep ancestor, late surviving Huehuecuetzpalli.

There was a flying model of Questz made by Paul Macready – but he made extra large, Pteranodon-sized wings. Comparisons shown here: https://pterosaurheresies.wordpress.com/2024/02/23/greg-pauls-iconic-flying-quetzalcoatlus-illustration-time-for-a-revision/

@12:01 the push-up take-off of Witton and Habib was debunked. This was Habib’s first paper so he can be forgiven for cheating pterosaur anatomy by placing the wing finger on the ground so it could build tendon tension, like a grasshopper hind leg, and catapult the pterosaur into the air with its wings not only still folded, but pointing down! Doomed to crash before the wings could be raised and flapped for the first time in mid-air – which the host called ‘hang time’. Only tiny vampire bats get away with this technique. No pterosaur tracks show anything but the three tiny free fingers creating impressions. The wing finger never impresses. Instead pterosaurs stood on hind limbs, like birds, and flapped with open wings while they leaped with their hind limbs to create maximum thrust and lift at takeoff. Details here: https://pterosaurheresies.wordpress.com/2018/06/02/why-we-think-giant-pterosaurs-could-fly-not/

BTW pterosaurs were able to FULLY fold their wings against their forelimbs so the membrane stowed away as completely as in bats.

@12:55 you can see how small the wings were, and how far from the center of balance they were. This model is going to nose dive, not glide. It also promotes the myth of the deep chord pterosaur wing plan. We have many soft tissue specimens of pterosaurs. None have wings attached to the ankles. No exceptions. All share a narrow chord wing membrane stretched between the wing tip and elbow with a fuselage filled between the elbow and mid thigh.

What did Quetz eat? Fossils were found in a shallow lake with a diverse assembly of arthropods, gastropods and bivalves. Quetz had long legs because it was a wader, a beachcomber. It was able to wade into deeper waters than its smaller relatives and younger selves. The stomach was very small relative to the giant head, long neck and limbs.

Why did Quetz retain the wings it did have? While not able to provide enough lift for flight, flapping still provided thrust = speed while running.

Hope this helps. There are many pterosaur myths out there. Some based on cheating anatomy – some based on continuing whatever is printed in college textbooks – and some based on supporting colleagues who may someday referee the manuscripts of their friends and allies.

” data-medium-file=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2021/12/conway-standing-quetzalcoatlus588.jpg?w=211″ data-large-file=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2021/12/conway-standing-quetzalcoatlus588.jpg?w=584″ class=”wp-image-63179 size-full” src=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2021/12/conway-standing-quetzalcoatlus588.jpg” alt=”Figure 1. Quetzalcoatlus freehand drawing from the memoire compared to an assembly of bones from the same memoire. ” width=”584″ height=”832″ srcset=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2021/12/conway-standing-quetzalcoatlus588.jpg?w=584&h=832 584w, https://pterosaurheresies.wordpress.com/wp-content/uploads/2021/12/conway-standing-quetzalcoatlus588.jpg?w=105&h=150 105w, https://pterosaurheresies.wordpress.com/wp-content/uploads/2021/12/conway-standing-quetzalcoatlus588.jpg?w=211&h=300 211w, https://pterosaurheresies.wordpress.com/wp-content/uploads/2021/12/conway-standing-quetzalcoatlus588.jpg 588w” sizes=”(max-width: 584px) 100vw, 584px” />

 Figure 1. Quetzalcoatlus freehand drawing from the memoire compared to an assembly of bones from the same memoire.

Like giant flightless birds,
pterosaurs became over-sized and oddly proportioned giants because they were flightless. We know this because little Q’s distal wing phalanges were vestigial. That’s called ‘a clue!’ Pteranodontids and ornithocheirids had much larger wings and they were smaller, much smaller overall. Let’s remember that weight increases by the cube of the length. So bigger aircraft need bigger wings at the same airspeed. Ask any pilot who has to calculate the number of passengers and their baggage and their weight. Overweight small planes tend to crash. https://pterosaurheresies.wordpress.com/2018/06/02/why-we-think-giant-pterosaurs-could-fly-not/

@6:21 pterosaurs are not related to dinosaurs. They do share hollow bones, a simple hinge ankle joint and an antorbital fenestra, but the list is short. A 2000 paper used three phylogenetic analyses to recover pterosaurs from Cosesaurus, Sharovipteryx and Longsiquama all flightless, bipedal lepidosaurs (but not lizards = squamates). We know they flapped due to a sternal complex created by the fusion of the clavicles, sternum and interclavicle, as in pterosaurs. These taxa also had an elongate, locked down coracoid, as in birds. That’s different from the small sliding coraocoid of quadrupeds. A bipedal gait is shown by the dinosaur-like anterior extension of the ilia incorporating more sacrals in the vertebral series. These taxa had an attenuated tail, as in pterosaurs , which means they had a vestigial caudofemoralis muscle, so a prepubis appeared to help move the femur. All three had a pteroid and strap-like scapula, as in pterosaurs. All three had pterosaur-like soft tissue,, including uropatagia behind each hind leg and fibers emanating from behind the forelimb. These taxa shared an odd lateral toe morphology with pterosaurs in which the metatarsal was short, the first phalanx was robust and as long as the other metatarsals and the next phalanx was just as long, but folded back so that when walking with a digitigrade stance this outer toe made a small dimple far behind the anterior four phalanges. We have those tracks. They are called Rotodactylus. Later beachcombing pterosaurs with a vestigial lateral toe became flat-footed and quadrupedal. Their tracks are much more abundant than early bipedal pterosaur tracks. A 2002 paper showed that, like birds, the wings came last and they were originally used for mating rituals, enhanced in visual splendor by flapping.

@7:27 adult pterosaurs range down past the size of a sparrow down to the size of a bee hummingbird, the smallest living bird. There are no ‘huge gaps’ in our knowledge of pterosaur interrelationships according to the large pterosaur tree, a cladogram with an unsurpassed 266 taxa. All taxa blend together as in microevolution. At the genesis of new clades phylogenetic miniaturization is common, in which smaller pterosaurs become precocious in a series of generations, laying eggs while their bones still showed juvenile traits. Speaking of which, hatchlings had adult proportions, a trait inherited from their deep ancestor, late surviving Huehuecuetzpalli. There was a flying model of Questz made by Paul Macready – but he made extra large, Pteranodon-sized wings. Comparisons shown here: https://pterosaurheresies.wordpress.com/2024/02/23/greg-pauls-iconic-flying-quetzalcoatlus-illustration-time-for-a-revision/

@12:01 the push-up take-off of Witton and Habib was debunked. This was Habib’s first paper so he can be forgiven for cheating pterosaur anatomy by placing the wing finger on the ground so it could build tendon tension, like a grasshopper hind leg, and catapult the pterosaur into the air with its wings not only still folded, but pointing down! Doomed to crash before the wings could be raised and flapped for the first time in mid-air – which the host called ‘hang time’. Only tiny vampire bats get away with this technique. No pterosaur tracks show anything but the three tiny free fingers creating impressions. The wing finger never impresses. Instead pterosaurs stood on hind limbs, like birds, and flapped with open wings while they leaped with their hind limbs to create maximum thrust and lift at takeoff. Details here: https://pterosaurheresies.wordpress.com/2018/06/02/why-we-think-giant-pterosaurs-could-fly-not/ BTW pterosaurs were able to FULLY fold their wings against their forelimbs so the membrane stowed away as completely as in bats.

@12:55 you can see how small the wings were, and how far from the center of balance they were. This model is going to nose dive, not glide. It also promotes the myth of the deep chord pterosaur wing plan. We have many soft tissue specimens of pterosaurs. None have wings attached to the ankles. No exceptions. All share a narrow chord wing membrane stretched between the wing tip and elbow with a fuselage filled between the elbow and mid thigh.

What did Quetz eat?
Fossils were found in a shallow lake with a diverse assembly of arthropods, gastropods and bivalves. Quetz had long legs because it was a wader, a beachcomber. It was able to wade into deeper waters than its smaller relatives and younger selves. The stomach was very small relative to the giant head, long neck and limbs. Why did Quetz retain the wings it did have? While not able to provide enough lift for flight, flapping still provided thrust = speed while running. Hope this helps. There are many pterosaur myths out there. Some based on cheating anatomy – some based on continuing whatever is printed in college textbooks – and some based on supporting colleagues who may someday referee the manuscripts of their friends and allies.