It’s always good to see pterosaurs on film or video. Too often its a disappointment as we’ve seen earlier with a National Geographic video. Usually it’s the same old dreadful stuff (list below), as archaic in thinking as tail-dragging dinosaurs. But here they toss in some novel ideas that will blow your mind (Fig. 1).
Why have pterosaurs been so singularly disfigured in morphology and behavior?? It’s like everyone involved has decided to discard their thinking caps!
Click here for part 1 of David Attenborough’s Flying Monsters 3D, presented by Serengeti Entertainment, an IMAX presentation now available on YouTube in five parts. The quality is excellent, so be sure to [fill your screen] with the video.
Figure 1. Here’s a first: Tapejara using its wings and head crest to sail instead of fly, following hypotheses put forth by Dr. Sankar Chatterjee. These pterosaurs are not flapping. They are holding their wings up like masts (at great strain, I might add). They have no underwater keel, so how they are keeping upright is a mystery. Glad to see someone out there is really out there! Grist for the mill, of course.
The usual anatomical rants:
The animators of FM3D got their data from traditional pterosaur workers, the ones who are holding back real research and continuing to hold fast to bogus data, like:
- Deep chord wing membranes attached to the ankles.
- In basal pterosaurs, a single uropatagium from leg to leg, not including the tail.
- In derived pterosaurs, useless uropatagia not providing lift for posteriorly directed hind limbs.
- Flat wings with no camber.
- No arm muscles. Too little thigh muscles.
- Fingers pointing forward while terrestrial or arboreal.
- Pedal digit 5 on basal pterosaurs not being used beneath a digitigrade pes.
- No idea where pterosaurs came from or how they developed wings.
Topic 1. How did pterosaurs first take to the air?
Attenborough’s narrative suggests it was the quest for flying insects, or to get from tree to tree in search of crawling insects that drove pre-pterosaurs to develop wings. Draco volans, the rib-gliding lizard, is Attenborough’s analog. Of course, this entirely misses the development of bipedal locomotion and flapping and only hints at the fact that traditional paleontologists are entirely stymied by the origin of pterosaurs. Sadly, today, there are even pterosaur ‘experts’ out there out don’t even know what a pterosaur is, or how pterosaurs fit into the reptile family tree! And there’s no excuse for that ‘nowadays’ with phylogenetic analysis — that is, unless those paleontologists have willfully decided to turn a blind eye toward good data and refuse to test the best working hypotheses for fear of having to retreat from their untenable claims. Of course, there’s motive and opportunity here.
We do get a good view of the rib-gliding lizard, Draco, landing on a tree (this may be CG = computer graphics) with full deployment of the rib membranes in the vertical plane creating maximum drag and a four-point landing right in front of the camera!
Topic 2. Flapping
Attenborough takes us to the white Jurassic cliffs along the coast of Dorset, England, to introduce us to the story of Mary Anning. This is a skillful redirection away from the actual origins of flapping, but allows Attenborough to introduce us to Dimorphodon, his most basic pterosaur complete with pedal digit 5 pointing medially at full extension toward the tail, framing the full uropatagium stretched between the hind limbs beneath the tail. Here the wings are too short and the tail is way-way too short. There are no Triassic pterosaurs featured in the film.
Click here for part 2
Topic 3. Eating
Dimorphodon flies through swarms of insects, gathering them with its (too wide) mouth. A very narrow skull is actually present. Here the hind legs and feet are improperly positioned in the horizontal plane while flying. That’s because Dimorphodon had dinosaur-like hind limbs, with femoral head at right angles to the shaft, unable to rise to the horizontal plane. Such legs were good for bipedal locomotion on dinosaurs – but evidently the experts hold a prejudice against that activity in pterosaurs.
Crashing into another Dimorphodon on the wing leads to our hero dropping into a river then sinking to the bottom to initiate fossilization.
Topic 4. Finding fossils and the wing joint
From there we segue to the Solnhofen limestone quarry where Attenborough splits limestone hoping to find a specimen. We meet the darkwing specimen of Rhamphorhynchus, famous for preserving so much detail in the wings. Attenborough notes the “miracle joint” (the wing joint) “to move their fingers in any direction,” and that “allowed them to fold up their wing when they landed.” Unfortunately, the next scene and all other pterosaur scenes do not show the wings folded as they could be, making the membrane essentially disappear, as shown in fossils, but rather the wing fingers never quite closes up because the too-large deep chord membrane is always present, hanging like a blanket, as it does in virtually all pterosaur movies. : (
Topic 5. Darwinopterus and the pterodactyloid transition
David Attenborough next pays a visit to Dr. Dave Unwin who presents Darwinopterus, which he thinks bridges the gap between basal, long-tailed pterosaurs and later, short-tailed forms. Actually, as we have seen earlier here and here, tiny pterosaurs bridge that gap and Darwinopterus is a dead-end pre-scaphognathid pterosaur close to Pterorhynchus leaving no descendants. Darwinopterus simply has a longer neck and longer rostrum than most basal pterosaurs, but the longer skull has its origins with Pterorhynchus at the base of that clade. Dr. Unwin describes Darwinopterus as a “weird mix of characters, primitive and advanced, a little bit like Frankenstein’s monster.” Someone should inform Dr. Unwin that evolution doesn’t work like this. It doesn’t work in modules. That’s why, if you study pterosaur feet, or any other sort of animal feet, you can make a pretty good guess what sort of skull it had. At the time scales involved, every part of the body evolves, not just the head or the tail. Not permitting tiny pterosaurs into his database was Unwins’ downfall, and he’s had many.
Topic 6. Wing design
“Very efficient in the air, but they [wings] evolved at a cost,” reports Attenborough. Dr. Unwin shows us a wire-frame model Rhamphorhynchus that flaps then lands, getting quadrupedal ASAP (Fig. 3).
Unwin’s model displays the fingers-forward error, which no tracks ever show. Attenborough tells us, “It’s easy to see that walking on flat surfaces would have been quite difficult for it.” The hands implant at twice or thrice the distance apart from the centerline as do the feet, which again do not match the fossil record. Experimenting with a bipedal pose, Unwin’s model Rhamphorhynchus tail catches or drags on the ground and walks like young Forrest Gump in leg braces. Why this is so is difficult to say because pterosaur tails were very flexible at the base of the pelvis and stiff only some distance beyond that. Clearly any pterosaur could raise its tail over its head Fiig. 2), let alone extend it directly out behind, like a bird. We even have bipedal pterosaur tracks.
Figure 2. The darkwing specimen of Rhamphorhynchus muensteri demonstrating the ability to raise its tail while bipedal. The wing membrane is shown expanded here, for illustrative purposes, but would have folded much more tightly against the spar in life. And note, there is no awkward and untenable membrane from the forelimb to the ankle here, as in figure 3.
Topic 7. Walking styles
Dr. Unwin argues for a quadrupedal terrestrial locomotion in Rhamphorhynchus, despite the universally acknowledged handicaps it presents and lack of evidence for any basal pterosaur to walk quadrupedally. And this situation is not improved by leaning too far forward (as in Fg. 3), as Unwin proposes. Moreover, Unwin’s Rhamphorhynchus with its leg-to-leg uropatagium and deep chord to the ankle wing membranes creates a three-sided tent beneath the pterosaur that cannot fold away.
Figure 3. Wireframe Rhamphorhynchus by David Unwin. The uropatagium (between the legs) and the deep chord wing membrane combine to produce a three-sided tent, ideal for catching the wing like a parachute.
These three fictitious membranes would make great wind catchers should any light breeze or strong storm seek to push a pterosaur off its perch. Such errors would have made pterosaurs virtual open parachutes. The preferred anatomy (Fig. 2) shows any pterosaur could have folded up its wing membrane virtually completely, assisted by the internal fibers, and, of course hunkering down when it really gets windy.
Click here for part 3
Topic 8. Pterodactyls
We get to meet “new style” pterosaurs, or pterodactyls, in Crayssac, France. Attenborough reports “the membrane between the legs split.” Ouch! According to more accurate data, there never was a membrane stretched between the legs. In Sordes that was a displaced ulna and radius together with some displaced wing membrane shown here. The darkwing Rhamphorhynchus clearly shows two uropatagia, but, sadly, like Creationists, traditional pterosaur workers continue to politely ignore such readily seen data.
Topic 9. Crayssac Tracks
Attenborough tells us the manus impressions at Crayssac are made by “the knuckles” and that the wing finger was the “little” finger, rather than digit 4. Both wrong, of course.
Then a little Pterodactylus runs across its own tracks, much as in this animation. Happily the wing is much narrower in chord, but the animators force the poor creature into a hunchback so that it’s wrists are unnaturally bent too far, like an old crone with walking sticks. Straightened up a bit and the walk would have been near perfect. Sadly, even with these narrower chord membranes, the animators continued to extend the wing membrane down the leg, even though this added nothing to the aerodynamics and only served to reinforce an old stereotype that needs to be abandoned. Also unfortunately, the animators paid little heed to the manus tracks and continued to plant the free fingers far outside their path.
Figure 4. Click to animate. Plantigrade and quadrupedal Pterodactylus walk matched to tracks
“The new ability to walk had a profound effect on pterosaur evolution,” Attenborough says. This is the current paradigm???!!! No wonder we’re in trouble. So in pterosaurs, according to Attenborough, first they could walk, then they couldn’t, then they could. Yeah.
Pterodaustro is shown with its sieve-like jaws. Pteranodon should have a sword-like rostrum, but here it is sword-like horizontally as well, creating a sort of box shape. Never saw that before. Hope to never see it again.
Topic 10. Pteranodon soaring
Pteranodon is shown in all of its majesty, with a deep chord membrane soaring above the clouds.
Then Archaeopteryx is introduced as half-reptile, half-bird.
Click here for part 4
Topic 11. Tapejara crests
Dr. Sankar Chatterjee works on Tapejara in Texas. He says the giant soft tissue crest is a steering device, a wind sensor and a rudder in front to be more aerobatic. All this is probable. Attenborough reports that some specimens of Tapejara had fur, which means they were warm-blooded. A little late to be saying that… because we learned earlier that such pycnofibers preceded pterosaurs and go all the way back to Sharovipteryx and Cosesaurus. Then Chatterjee goes out on a limb when he reports pterosaurs used their open and upraised wings as sails when floating on the sea (Fig. 1). Of course, lifting the arms for extended periods during windy conditions is most tiring. Chatterjee reports, “The head crest would be just like a jib.”
Isn’t it much easier to just fly, with the wings supported by the airstream and without all that hydrodynamic drag? Ducks and geese use water to slow down their landings, after all. There was one example of a forelimb takeoff, but it was off the side of a cliff. Luckily so, otherwise the ensuing drop would have been a crash before the first wing flap. (See, I told ya!)
Topic 12. Pterosaur eggs
Attenborough shows us a pterosaur egg with well-formed wings, which tells us the chick was able to fly immediately after hatching. “Embryo bones,” Attenborough tells us, “develop differently in pterosaurs than in birds. And this led to some pterosaurs becoming gigantic.” Well, actually we’ve had big birds, too, like elephant birds, much larger than most pterosaurs.
Topic 13. Quetzalcoatlus Introduced
The subject of giants takes us to Big Bend National Park, home of Quetzalcoatlus, which was so big, Attenborough tells, “for years some scientists r to believe that it could have existed.” That’s news to me. I thought everyone accepted it from the start.
We meet Doug Lawson, who found Q. on a sandstone hillside. Later Q is shown scavenging a dead dinosaur, its only competition is another Q. Some rummaging lizards get picked up and slurped down to their dismay in a nod toward the Witton and Naish.
Click here for part 5
Topic 14. Pterosaur Takeoff
How did Quetzalcoatlus get off the ground? A CT scan of the humerus reveals the insides but in CG. The supporting struts are said to line up in one direction for maximum strength in that dimension. Then we meet Mike Habib’s Anhanguera again, catapulting its body skyward at a reported 35 miles per hour. That’s so hard to believe when smaller, more muscular kangaroos can only manage no more than 16 mph on the first hop with better leverage and bigger muscles. Earlier we looked at the impossibility of a forelimb launch using larger bones but much smaller muscles in the arm compared to the leg.
The precisely engineered sailplane (with narrow-chord wings!) that comes up next is airborne at 46 mph. Of course with the deep chord wing membrane the flaps on Attenborough’s pterosaurs are virtually always extended, creating more lift and drag, especially so during the launch with legs extended down. That’s not the optimal sailplane wing shape that reptileevolution.com champions. There is a better way to get airborne and that is by using those long wings to create something the engineers call, “thrust” which can be directed down and back at the same time.
Topic 15. Asteroid impact? Or the domination of birds?
Part five finishes with a standard asteroid impact, but Attenborough blames the birds for setting pterosaurs on the path toward extinction. He tells us, birds had the advantage of decoupled wings, not attached to the legs. “No pterosaurs, encumbered by their skinny wings could wade like flamingoes,“ Attenborough reports. Yet that’s exactly what wading pterosaurs, like Ctenochasma, Quetzalcoatlus and Pterodaustro did! We have their footprints! Attenborough is correct, however, if pterosaurs had put on the wrong wing membrane when they got out of bed. If a deep chord membrane got into water, it would have filled up with water. Thankfully that problem never happens with a narrow-chord membrane.
Figure 6. Click to enlarge. Revised Qiuetzalcoatlus from Flying Monsters 3D with David Attenborough.
So much effort goes into making these animated films. It’s just too bad they’re working from such out-dated blueprints of disfigured pterosaurs.
Mark Witton reported here, “A handful of pterosaur researchers were consulted in the making of the film, too – David Unwin, David Martill, Michael Habib and myself were all involved to ensure the science was on the money. With credentials like that, it’s understandable that expectations were higher for this than for many palaeodocs and, indeed, the programme has caused a stir around the world with palaeobloggers-a-plenty eager for it to land on their cinematic shores this Spring. Problem is, once you’ve taken in how nice everything looks, you start to focus on the story you’re being told and the content of the programme, and that’s where the issues begin.” And Mark lists many issues I glossed over (and ignores others that are not problems according to him.) He summarizes:
“It really seems that, with a bit more care, this could’ve been as much of an achievement for effective scientific communication as it has been for 3D technology, but it’s really an enormous missed opportunity.”