Anhanguera animation at the NHM (London)

This one started off with so much promise
as the animators at the National History Museum (NHM) in London assembled their version of the ornithocheirid pterosaur, Anhanguera, bipedally (Fig. 1), as you’ll see when you click on the video under ‘References’.

Figure 1. Animated by the NHM, Anhanguera is bipedal and flapping its literally oversize wings.

Figure 1. Animated by the NHM, Anhanguera is bipedal and flapping its literally oversize wings standing on oversize feet with an undersized skull and hyperextended elbows and unbalanced stance.

Unfortunately there were some morphology issues (compared in Fig. 2):

  1. wings too long
  2. sternal complex missing
  3. gastralia missing (but rarely preserved in ornithocheirids)
  4. feet way too big
  5. skull too small
  6. tail too short
  7. not sprawling
  8. free fingers too big
  9. wing fingers should tucked tight against elbows (in the same plane)
  10. one extra cervical
  11. anterbrachia too short and gracile
  12. elbows overextended (in Fig. 1)
  13. too much weight put on forelimbs, center of balance (wing root) should be over the toes
  14. Prepubes are extremely rare in ornithocheirds, but when present they are tiny, putter-shaped and oriented ventrally in line with the bent femora, not anteriorly
Figure 2. NHM Anhanguera compared to skeletal image from ReptileEvolution.com.

Figure 2. NHM Anhanguera compared to skeletal image from ReptileEvolution.com. There are at least 10 inaccuracies here. See text for list.

Also unfortunately, the video quickly devolved
to the invalid and dangerous quad launch, when (doggone it!) it was all set up to do a more correct and  much safer bird-like launch. The laws of physics and biomechanics are ignored here, but at least David Attenborough narrates.

Figure 3. NHM Anhanguera quad launch select frames.

Figure 3. NHM Anhanguera quad launch select frames. The laws of physics and the limitations of biomechanics are ignored here.

Attempts to convince readers and workers
that the quad-launch hypothesis cheats morphology and physics (as recounted here and at links therein) have so far failed. But I’m not giving up. So, if anyone has a connection to the NHM in London, please make this post available to alert them of their accidental foray into wishful thinking and inaccurate morphology.

References
National History Museum (NHM) in London

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Time to trash the widely embraced ‘Azhdarchoidea’

According to Wikipedia
Unwin (2003) defined the group Azhdarchoidea as the most recent common ancestor of Quetzalcoatlus and Tapejara, and all descendants.

Unfortunately
Unwin’s phylogenetic analysis excluded several dozen relevant taxa. When those are added back in, as shown in the large pterosaur tree (LPT, 232 taxa), azhdarchids arise from certain phylogenetically miniaturized Dorygnathus clade specimens (TM 10341) while tapejarids arise from certain phylogenetically miniaturized germanodactylids (Nemicolopterus) and before that, phylogenetically miniaturized scaphognathids (Ornithocephalus brevirostris, BSPG 1971 I 17). Tapejarids and azhdarchids don’t have a common ancestor in the LPT until you go back to Sordes PIN 2585-25. And that was not the intent of Unwin 2003.

Competing hypotheses of relationships
by Naish and Martill 2006; Lu et al. 2008; Pinheiro et al. 2011; and Andres, Clark and Xu 2014 all suffer from the same cherry-picking and taxon exclusion issues. At least Vidovic and Martill 2014 added germanodactylids and dsungaripterids nesting basal to tapejarids, but failed to add dorygnathids and pre-azhdarchids among other relevant taxa basal to azhdarchids. By the way, you heard it here first: germanodactylids and dsungaripterids were ancestral to tapejarids. Thanks are due to Vidovic and Martill for confirming this.

Pterosaur workers are ‘missing the boat’
when they are content to cherry pick traditional genus-based taxa. If they were to employ more specimen-based taxa in an unbiased fashion, as the LPT does, they, too, would recover a wealth of interrelationships otherwise invisible to them.

The clade name Azhdarchia
is hereby defined as TM 10341, Beipiaopterus, their last common ancestor and all descendants. These include Huanhepterus, Ardeadactylus, CM 11426, BSPG 1911 I 31, the flightless azhdarchid JME-Sos 2428, JME Sos 2179, and the traditional azhdarchids, Jidapterus, Chaoyangopterus, Zhejiangopterus, Azhdarcho, Quetzalcoatlus and kin. With origins in the late middle Jurassic, and no matter what size, these are all stork-like waders, gradually getting phylogenetically larger, toothless and ultimately flightless as their distal wing phalanges become vestiges.

The Azhdarchidae.

Figure 1. The Azhdarchidae. Click to enlarge. (That’s a juvenile Zhejiangopterus shown). These are all waders.

We already have a suitable name for the clade Tapejaridae,
which developed elaborate head crests and never stopped flying (so far as is known), based on their elongate distal wing phalanges.

The new skull compared to other tapejarids. Click to enlarge.

Figure 2. Click to enlarge. The rising size of the tapejaridae. These are not waders.

The expansion of the antorbital fenestra above the level of the orbit
in tapejarids and azhdarchids is (I hate to be the only one saying the obvious) a convergent trait. LPT relationships were introduced and published in Peters 2007, and (with a few modifications to incomplete taxa) hold true today. Peters 2007 reported, Major clades typically have a spectral series of tiny pterosaurs at their base suggesting that paedomorphosis was a major factor in pterosaur evolution.” Since then, no other workers have included the vital and relevant tiny pterosaurs in their phylogenetic analyses.

It is also time to trash the clade ‘Pterodactyloidea’
When tiny pterosaurs are added to a phylogenetic analysis (click here) the traditional clade ‘Pterodactyloidea’ divides into two clades that arise from tiny Dorygnathus derived taxa (Fig. 1) and two more that arise from tiny Scaphognathus derived taxa (Fig. 3), for a total of four pterodactyloid-grade taxa. There’s one more semi-pterodactyloid clade,  Darwinopterus and kin, with a large skull and long neck, but also a long tail. And yet another, the anurognathids that do not have a large skull (exception: Dimorphodon) and long neck. However anurognathids do shrink the tail, a pterodactyloid-grade trait that Longrich, Martill and Andres 2018 used to nest anurognathids as the proximal outgroup to their clade ‘Pterodactyloidea’ with the mistakenly reconstructed Kryptodrakon (= Sericiterus) at the base. The LPT lumps and splits all pterosaurs in a logical and tenable fashion.

Figure 1. Scaphognathians to scale. Click to enlarge.

Figure 3. Scaphognathians to scale. Click to enlarge.

From one generation to another
If you were a full professor, would you venture to include taxa suggested by an amateur? So far, none have shown the courage to do so (see below), while outside of pterosaur studies, confirmation of discoveries first announced here has happened several times (e.g. Chilesaurus), without citation. So methods used here work.

Dr. S. Christopher Bennett once told me:
“If you submit that manuscript, it will not get published. And if you somehow get it published it will not get cited.” Uncanny how that prophecy came true… but it doesn’t reflect on the value of the manuscript.

And that’s why
this blog and the website ReptileEvolution.com were launched, outraged at the insanity and insular thinking out there.

PS. As I write this,
Bestwick, Unwin, Butler, Henderson and Purnell (2018) compiled statistics on pterosaur dietary preferences (over 300 pterosaur dietary statements identified from 126 published studies) employing a traditional cladogram with the tiny hand, four-toed crocodylomorph, Scleromochlus as the outgroup, anurognathids basal to eudimorphodontids, wukongopterids basal to ‘pterodactyloids’, cycnorhamphids nesting with ctenochasmatids, pteranodontids nesting with ornithocheirids, and tapejarids nesting with azhdarchids, with loss of resolution at half the nodes. It’s quite disheartening to see this, when we know better… through specimen-based taxon inclusion.

Pity the first author, poor PhD student (U of Leicester) Jordan Bestwick. He is under the tutelage of Dr. David Unwin. You might remember Leicester, was earlier seeking a pterosaur tracker, a student who could somehow find evidence for the invalidated pterosaur forelimb launch hypothesis. Evidently, this is how they operate: Don’t find out for yourself… rather your job is to continue the legacy and dictates of your professor(s).

In addition to the invalid Azhdarchoidea,
Dr. Unwin has promoted:

  1. the invalid ‘uropatagium‘ incorporating pedal digit 5 in basal pterosaurs
  2. the invalid deep chord wing membrane of pterosaurs
  3. the invalid quadrupedal basal pterosaur hypothesis
  4. the invalid pterosaur egg burial hypothesis
  5. the invalid quad-launch hypothesis of pterosaur takeoff
  6. the invalid archosauromorph (Scleromochlus) origin of pterosaurs (see above)
  7. the invalid modular evolution hypothesis to support
  8. the invalid nesting of the Darwinopterus clade basal to
  9. the invalid Pterodactyloidea.

Anyone can test these hypotheses by
adding taxa to current published studies using whatever characters one chooses. Really. That’s all it takes to upset these cherry-picked (taxon exclusion riddled) studies.

References
Andres B, Clark J and Xu X 2014. The Earliest Pterodactyloid and the Origin of the Group. Current Biology24: 1011–6.
Bestwick J, Unwin DM, Butler RJ, Henderson DM and Purnell MA 2018. Pterosaur dietary hypotheses: a review of idea and approaches. Biological Reviews online pdf
Longrich NR, Martill DM and Andres B 2018. Late Maastrichtian pterosaurs from North Africa and mass extinction of Pterosauria at the Cretaceous-Paleogene boundary. PLoS Biology, 16(3): e2001663.
Lü J, Unwin DM, Xu L and Zhang X 2008. A new azhdarchoid pterosaur from the Lower Cretaceous of China and its implications for pterosaur phylogeny and evolution. Naturwissenschaften. 95 (9): 891–897.
Pinheiro FL et al. (4 co-authors) 2011. New information on Tupandactylus imperator, with comments on the relationships of Tapejaridae (Pterosauria). Acta Palaeontologica Polonica. 56 (3): 567–580.
Peters D 2007. The origin and radiation of the Pterosauria. Flugsaurier. The Wellnhofer Pterosaur Meeting, Munich 27.
Unwin DM 2003. On the phylogeny and evolutionary history of pterosaurs. Pp. 139-190. in Buffetaut, E. & Mazin, J.-M., (eds.) (2003). Evolution and Palaeobiology of Pterosaurs. Geological Society of London, Special Publications 217, London, 1-347.

wiki/Azhdarchoidea
wiki/Pterodactyloidea

 

Azhdarcho restored (from bits and pieces)

Earlier
we looked at the neck and skull of Azhdarcho… Today we’ll put all the bits and pieces we know (from several individuals, unfortunately) to see what we get, following the Q. sp. bauplan (Fig. 1).

Figure 1. Azhdarcho to scale with more complete smaller Quetzalcoatlus specimen and in proportion to the bauplan of Q. sp. Note the robust femur and gracile humerus. These together with the small sternal complex and short distal wing elements indicate a flightless condition.

Figure 1. Azhdarcho to scale with more complete smaller Quetzalcoatlus specimen and in proportion to the bauplan of Q. sp. Note the robust femur and gracile humerus. These together with the small sternal complex and short distal wing elements indicate a flightless condition.

Azhdarcho lancicollis (Nesov 1984, Averianov 2010) is the namesake for the clade Azhdarchidae. This species is known from several individuals of various sizes and very few complete bones. That is why reconstructions of this genus are rare. This reconstruction is based on the more complete Q. sp., but about half as tall.

Given these limitations,
(no complete long bones), the femur appears to be more robust than in other azhdarchids, while the humerus is more gracile. Only in Huanhepterus is the femur so relatively short. The sternal complex is quite small, but with a deep cristospine, distinct from other azhdarchids. (Perhaps the rest of the sternal complex is missing.) Manual 4.4 was identified by Averianov, but it appears to be the distal portion of m4.3. The scale bars for the distal femur appear to be in error, or apply to a much larger individual (see Fig. 1).

The invisible aid in this reconstruction
is the observation that in nearly all post-Huanhepterus azhdarchids, the metacarpus, manual digit 4 and tibia are similar in length (Fig. 1), no matter how small or tall… probably to facilitate terrestrial locomotion.

Unfortunately,
not enough is known of Azhdarcho to add it to the LRT. So much has to be imagined.

References
Averianov AO 2010. The osteology of Azhdarcho lancicollis Nessov, 1984 (Pterosauria, Azhdarchidae) from the Late Cretaceous of Uzbekistan. Proceedings of the Zoological Institute of the Russian Academy of Sciences, 314(3): 246-317.
Nesov LA 1984. Upper Cretaceous pterosaurs and birds from Central Asia. Archived 17 March 2012 at the Wayback Machine. Paleontologicheskii Zhurnal, 1984(1), 47-57.

wiki/Azhdarcho

Battle of the giant Quetzalcoatlus sculptures

Bigger is better
especially when it comes to pterosaurs in museum exhibits. To wit: The Field Museum (Chicago, IL, USA) is installing a flying Quetzalcoatlus (Fig. 3) and a standing Quetzalcoatlus (largely imagined and restored, based on an almost complete wing bone, Fig. 1).

The artist/professors in Southern England
have one as well (Fig. 1). And full scale Q. northropi sculptures can be found worldwide! (See links and images at the end of this post.)

Figure 1. Field Museum Quetzalcoatlus (tan) vs. English Quetzalcoatlus (gray) vs. a tracing of the real Q. sp. and Q. northropi scant remains.

Figure 1. Field Museum Quetzalcoatlus (tan) vs. English Quetzalcoatlus (gray) vs. a tracing of the real Q. sp. and Q. northropi scant remains. Yes, the skull on the Field Musuem model is too long, evidently following the invalid archosaur hypothesis of origin. Pterosaurs, like other tritosaurs, do not change their proportions during growth as fossils demonstrate.

These models arrive on the heels
of a recent post on flightless giant pterosaurs. The Field Museum model (Fig. 1) appears to have a more precisely modeled skull, though about 50% too long (but really, without a skull, who knows?). Perhaps the skull was elongated (based on the smaller ?species) based on the invalid archosaur hypothesis of pterosaur origins. We know from the evidence of fossils that hatchlings and juvenile pterosaurs had adult proportions, not longer skulls.

Both models suffer
from putting too much weight on the tiny free fingers. The feet should be beneath the shoulder joint, as in birds, to take the weight off the tiny hyperextended fingers, acting more like ski poles, not providing thrust, only some sort of support.

The folded wing membrane should tend to disappear
(Fig. 2), but it shows in both models. The wing finger should flex closer to the elbow, but it doesn’t (probably to let the wing membrane show). The wing membrane chord should be shorter, to the elbow, but in both models the brachiopatagium blends with the leg, always awkwardly and in defiance of the data preserved in all pterosaur fossils (Fig. 2) that preserve soft tissue.

Here's how the wing membrane in pterosaurs virtually disappeared when folded.

Figure 2. Here’s how the wing membrane in pterosaurs virtually disappeared when folded. This is a tiny pre-azhdarchid, CM 11426.

Over at the Carnegie Museum (Pittsburgh, PA, USA)
they have a tiny pre-azhdarchid, CM 11426 (Fig. 2), with real wing membranes, as described above, matching those of other pterosaur soft tissues.

Figure 3. Field museum flying Quetzalcoatlus model has the invalid deep chord wing that attaches to the tibia.

Figure 3. Field museum flying Quetzalcoatlus model has the traditional but invalid deep chord wing that attaches to the tibia and makes this sort of pterosaur untenably awkward.

Figure 2. Quetzalcoatlus recreated as a digital model by Henderson 2010 compared to a bone reconstruction. No wonder the results were odd. The math was wrong.

Figure 4. Quetzalcoatlus recreated as a digital model by Henderson 2010 compared to a bone reconstruction. This is a possible slightly deeper wing chord. Compare this one to figure 5, which is more typical. And look at those hind limbs, like those of Sharovipteryx, forming a horizontal stabilizer, just like a typical airplane. And it matches the evidence (Fig. 2).

Not sure why pterosaur paleontologists
keep insisting that evidence (Fig. 2) can and should be ignored. It’s disheartening to see this and leaves them open to criticism.

Quetzalcoatlus running like a lizard prior to takeoff.

Figure 5. Quetzalcoatlus running like a lizard prior to takeoff. Click to animate. Giant azhdarchids gave up flying by reducing the lenth of their wings, following the patterns of other flightless pterosaurs. There is no awkwardness with this narrow chord wing design, which follows fossils like CM 11426 (Fig. 2).

Other online Quetzalcoatlus models/sculptures:

Low Poly Quetzalcoatlus model

https://www.alamy.com/stock-photo-muenchehagen-germany-10th-apr-2017-a-sculpture-of-the-quetzalcoatlus-138149396.html

https://blog.everythingdinosaur.co.uk/blog/_archives/2014/07/07/collecta-quetzalcoatlus-with-prey-model.html

If some of these seem to defy the ability to fly based on
a too far aft center of lift and a too far forward center of balance, or too small of a wing for such a large mass, no worries mate! If the imagination can soar, then so can these giants (NOT!) In the above YouTube video, the invalid, but traditional batwing shape of the brachiopatagium is best seen in the pterosaur’s shadow.

Quetzalcoatlus northropi

Tierra de dinos - Quetzalcoatlus Northropi

IF the wing membranes seem encumbering
awkward, liable to trip up the pterosaur or catch on some low lying shrub, no worried, mate! As these pterosaurs once wandered, let your imagination wander. There’s no need to precisely follow the evidence (Fig. 2) that shows the wing membranes essentially disappearing while flexed/folded.

Quetzalcoatlus at the Toledo Zoo

It’s going to be difficult to raise the wings for flight
given some of these awkward quadrupedal poses. Much better to have the center of balance over the toes at all static times (see below), shifting the balance forward while running at full speed (Fig. 5), like birds.

http://www.iaapa.org/DigitalShowDaily/2016/wed/Billings.asp

https://hiveminer.com/Tags/quetzalcoatlus

Why is this Houston Museum Quetzalcoatlus posed like this? Very strange.

Why is this Houston Museum Quetzalcoatlus posed like this? Very strange.

Quetzalcoatlus neck poses. Dipping, watching and displaying.

Quetzalcoatlus neck poses from David Peters Studio. Dipping, watching and displaying. Yes, the third finger is wrong here. It should be pointing posteriorly.

With what we know about pterosaurs
this should be a golden age of restoration. Instead, these models will someday be seen for what they are… near misses. They replace elegance with awkwardness, facts with fancy, and precision with tradition.

References
https://blog.everythingdinosaur.co.uk/blog/_archives/2018/06/01/pterosaur-models-go-on-display.html

Peters D 2002. A New Model for the Evolution of the Pterosaur Wing – with a twist 
Historical Biology 15: 277-301

Bird, pterosaur, dinosaur simplified chronology

Following the earlier post on non-arboreal post K-T boundary birds…

…this one pretty much speaks for itself.
Here (Fig. 1) is a chronology, very much simplified, of birds, pterosaurs and dinosaurs according to the LRT.

Figure 1. Mesozoic chronology of bird, dinosaur and pterosaur clades.

Figure 1. Mesozoic chronology of bird, dinosaur and pterosaur clades based on taxa in the LRT.

If you’re curious about any of the taxa,
in the chronology, simply use Keywords to locate them.

Ashland, Oregon, pterosaur exhibit

I recognized some of the models
in this traveling pterosaur exhibit (Fig. 1). They came from Triebold Paleontology, but originated at David Peters Studio. Unfortunately, I’m not keen on the poses the exhibitors gave these pterosaurs. Ironically they are sprawling, like lizards, but no one, but yours truly has adopted the lepidosaur origin of pterosaurs hypothesis.

FIgure 1. Pterosaur exhibit

Here’s the way
Pterodaustro should be posed (Fig. 2). It’s a wader, built for walking knee deep into still shallow waters to dip that long filter-toothed mandible — yet able, in a moment to leap into the air and take flight. Still the hind limbs are sprawling.

Figure 2. Pterodaustro sculpture

Here’s the way
Jeholopterus should be posed (Fig. 3), digitigrade with the shoulders directly over the toes.  The long finger claws of this vampire pterosaur were ideal for latching onto and in to, dinosaur skin. And this is the correct skull. Triebold, tossed out the correct skull and placed the more popular, but invalid, Bennett anurognathid skull (the one that mistook the mandibles for sclerotic (eyeball) rings.

Model of Jeholopterus, the famous vampire pterosaur.

Figure 2. Model of Jeholopterus, the famous vampire pterosaur.

Here’s the way
Dimorphodon would run around on the ground – digitigrade (proximal phalanges elevated, too), shoulders over the toes, pedal digit 5 retroverted. Nothing clumsy or awkward about this basal pterosaur! It was fast, agile and keeping those large finger claws sharp for clinging to tree trunks.

 

Figure x. Dimorphodon skeleton.

Figure x. Dimorphodon skeleton. The tail, not found with the rest of the skeleton, making this a chimaera, is too long.

Here’s the text of the online article:
“Long before Tyrannosaurus rex, the world was filled with pterosaurs — bizarre-looking flying reptiles, some as huge as a fighter jet, who ate everything, terrorizing the Mesozoic Age for 160 million years until they, like the dinosaurs, were killed off by a big asteroid.

“That little-known world, our window into which has been vastly expanded by science in the last few decades, has been recreated in a stunning new ScienceWorks Hands-On Museum exhibit that invites you, at one point, to virtually think, feel and fly like a pterosaur by flexing your arms and body.

“Entirely created by the Ashland’s museum staff and volunteers, it was built for under $250,000, a modest amount among museums these days, especially when they saw a San Francisco museum did their pterosaur exhibit for 30 times that, says Steve Utt, co-creator and president of ScienceWorks board of directors.

“Costs for ScienceWorks can be recouped by leasing it out, he says.

“A self-described “Silicon Valley escapee” eight years ago, Utt did all the seemingly magical if not miraculous software and video that plops you right in the middle of the pterosaur’s world, which started 228 million years ago and seems a lot stranger than any science fiction movie.

“Pterosaurs (pronounced “terra-soars”) have replaced the once terrible tyrannosaurus rex, hero of Jurassic Park, as an object of fascination because, says ScienceWorks exhibit director Leo Palombo, “there have been so many discoveries, so much we didn’t know about 10 or 15 years ago, and that’s what you see here — flying reptiles. They are not dinosaurs, not birds. Some had hair, not feathers — so many amazing sizes and shapes.”

“They all used to be called pterodactyls, but that word is outmoded now and applies only to a small subcategory. Displays at ScienceWorks seek to show the immense, newly-discovered range of body types, sizes, combs (those wild shapes on top of their heads), as well as their body architecture, which can only be described as an extremely inventive chapter of evolution.

“Displays explain that pterosaurs in general had long, pointy heads, usually with teeth, could fly up to 70 mph and would gather food by scooping it from water, land or air. They are not like bats, though they have skin-like wings, and these were made possible by the evolution of the fourth finger to hold a wing.

“Many of the exhibits teach you what various species did, how and where they did it — and then you turn around and there’s a video of a familiar beach on the Oregon coast with a couple of pterosaurs soaring in among the breakers, then alighting on our big beach rocks, where they sit and peck and preen. It’s just, simply, hard to believe this ever happened in what’s now Oregon, let alone that we have an accurate, scientific depiction of it.

“Len Eisenberg of ScienceWorks’ science advisory board stands at the most popular interactive pterosaur “ride,” urging participants to arch their heads back and wave their arms, as sensors pick up all these cues. There’s a learning curve and most who try it get chomped by a giant-jawed mososaur (sic) when they crash in the water. You get points for various foods you kill — squid, fish or ammonite. A sign shows the best score of the day, a 20, and you, usually have zero. It takes several times in a long line to get up to the skill of the pterosaur.

“This display and the science around pterosaurs is interesting because we’ve found lots more fossils and footprints in the last decade,” says Eisenberg, “all of which explain how they lived and got food.”

“Another interactive ride shows a seeming x-ray of your flapping human thorax, set beside the ancient creature and giving us a window on how much muscle and thin, fragile, lightweight bone had to be brought into play for it to fly.

“The stunning centerpiece of the new exhibit is the lifesize, 16-foot tall wood model of Quetzalcoatlus, the largest known flying creature of all time, which exhibit technician Rachel Benbrook and others fashioned using Turbo CAD and Adobe Illustrator.

“The public reception to this exhibit has been overwhelmingly positive and,” she says, “many people, seriously, have been blown away. That’s what we want — to inspire and encourage science education to the next level.”
— John Darling is an Ashland freelance writer. Reach him at jdarling@jeffnet.org.”

References

http://www.dailytidings.com/news/20180430/imagination-soars-at-pterosaur-exhibit

Quail hip joints are not good models for pterosaur hip joints

Manafzadeh and Padian 2018 tell us:
“Studies of soft tissue effects on joint mobility in extant animals can help to constrain hypotheses about joint mobility in extinct animals. However, joint mobility must be considered in three dimensions simultaneously, and applications of mobility data to extinct taxa require both a phylogenetically informed reconstruction of articular morphology and justifications for why specific structures’ effects on mobility are inferred to be similar. We manipulated cadaveric hip joints of common quail and recorded biplanar fluoroscopic videos to measure a ‘ligamentous’ range of motion (ROM), which was then compared to an ‘osteological’ ROM on a ROM map. Nearly 95% of the joint poses predicted to be possible at the hip based on osteological manipulation were rendered impossible by ligamentous constraints. Because the hip joint capsule reliably includes a ventral ligamentous thickening in extant diapsids,the hip abduction of extinct ornithodirans with an offset femoral head and thin articular cartilage was probably similarly constrained by ligaments as that of birds. Consequently, in the absence of extraordinary evidence to the contrary, our analysis casts doubt on the ‘batlike’ hip pose traditionally inferred for pterosaurs and basal maniraptorans, and underscores that reconstructions of joint mobility based on manipulations of bones alone can be misleading.”

Figure 6. Images of floating lizards. The small ones, like small pterosaurs, take advantage of surface tension to ride high while spread-eagle on the surface.

Figure 1a. Images of floating lizards. The small ones, like small pterosaurs, take advantage of surface tension to ride high while spread-eagle on the surface.

Manafzadeh and Padian 2018 are not phylogenetically informed.
They should have used lizards. Pterosaurs are not related to birds. Birds are archosaurs. Pterosaurs are lepidosaurs, which universally (except for legless taxa) assume a bat-like pose in their hind limbs when resting (Figs. 1, 2). Many articulated pterosaur fossils are found in the sprawling posture (Fig. 2) typically used for flying…but Manafzadeh and Padian are talking about quail hips and inferring similarity. That is the basic error here.

The clade ‘Ornitodira’
(= pterosaurs + dinosaurs, their last common ancestor and all descendants, Gauthier 1986) is a junior synonym for ‘Amniota’, which is a junior synonym for ‘Reptilia’ when more taxa are added to phylogenetic analysis, as demonstrated here: http://www.ReptileEvolution.com/reptile-tree.htm. This growing online study currently tests 1220 specimen-based taxa throughout the Tetrapoda. So here, as nowhere else, pterosaurs have the opportunity to nest with over 1200 candidate sisters.

Pterosaur outgroups
Macrocnemus, Tanystrospheus, Tanytrachleos, Langobardisaurus, Cosesaurus and Sharovipteryx are pterosaur outgroup taxa (Peters 2000, 2007) with an oblique femoral head and sprawling femora. In Peters (2000) pterosaurs and their outgroups were considered prolacertiforms, but with additional taxa (Peters 2007 and ReptileEvolution.com) taxa listed above join the lepidosaurs Huehuecuetzpalli and Tijubina in a new clade (Tritosauria) nesting between Rhynchocephalia (= Sphenodontia) and Squamata.

Pterosaur femur samples. A

Figure 1b. Pterosaur femur samples. Above, Pteranodon. Below, Anhanguera. Note the oblique angle of the femoral head. When the axes of the femoral neck and laterally-oriented acetabulum lined up a sprawling configuration was produced.

In pterosaurs the angle of the femoral shaft
in relation to the acetabular bowl is determined by the femoral neck, which is nearly at right angles to the shaft in the clade represented by Dimorphodon and Anurognathus. Padian famously compared erect Dimorphodon to erect birds (Padian 1987) and heartily endorsed the Ornithidira hypothesis without testing other pterosaur ancestor candidates among the Lepidosauria, some of which were not published until after 1987. In many other pterosaurs, like Anhanguera, Pteranodon and Quetzalcoatlus, the shaft and head of the femora are much more oblique (Fig. 1b), at times approaching collinear (Fig. 2). No pterosaur femora are presented in Manafzadeh and Padian 2018, only a quail pelvis and femur.

The Vienna Pterodactylus.

Figure 2. The Vienna Pterodactylus. Click to animate. Wing membranes in situ (when folded) then animated to extend them. The femora are sprawling because this is a lepidosaur, not an archosaur.

 

Young scientists:
Examples like Manafzadeh and Padian 2018 should inform you that even though some highly regarded paleontologists have made great discoveries and have stood up against Creationists, even they can put on blinders when it comes to direct attacks on cherished hypotheses. Neither Padian nor his students, nor any other professor nor their students, have ever, or will ever find pterosaur sister taxa among the Archosauriformes, no matter how much they believe that someday, somehow what they pray for and have faith in will happen. It’s been 18 years since the Ornithodira was struck down (Peters 2000) and pterosaurs were shown to nest outside the Archosauriformes. Padian and others simple ignore this trifle, hoping it will someday go away. And it will, unless others offer to take up the cause. Unfortunately, that’s the state of paleontology in 2018.

Everywhere, but here
testing the discoveries of others appears to be on the wane (see video below the references)… but that’s life. Question authority. Test evidence for yourself.

References
Gauthier JA 1986. Saurischian monophyly and the origin of birds. The Origin of Birds and the Evolution of Flight, K. Padian (ed.), Memoirs of the California Academy of Sciences 8:1–55.
Manafzadeh AR and Padian K 2018. ROM mapping of ligamentous constraints on avian hip mobility: implications for extinct ornithodirans. Proceedings of the Royal Society B Biological Sciences. Published 23 May 2018.DOI: 10.1098/rspb.2018.0727
Padian K 1983. Osteology and functional morphology of Dimorphodon macronyx (Buckland) (Pterosauria: Rhamphorhynchoidea) based on new material in the Yale Peabody Museum, Postilla, 189: 1-44.
Peters D 2000. A redescription of four prolacertiform genera and implications for pterosaur phylogenesis. Rivista Italiana di Paleontologia e Stratigrafia 106: 293-336.
Peters D 2007. The origin and radiation of the Pterosauria. Flugsaurier. The Wellnhofer Pterosaur Meeting, Munich 27

John Oliver thinks the following science problem is not funny.
Academic publications are unlikely to publish studies that simply confirm earlier discoveries. And yet… science depends on confirmation and ultimately consensus.

(Click to play video). After the first few minutes the video becomes less relevant):

As Oliver puts it:
There’s no Nobel Prize for fact checking.” Perhaps that is why few other workers are even considering taxa listed in the large reptile tree and large pterosaur tree that were shown to be relevant for more focused studies. And those that do (e.g. Baron and Barrett 2017 in their Chilesaurus study) are being notably taciturn about grabbing headlines for discoveries posted and time-stamped years earlier.

Quotes from this Oliver video:
“So you have all these exploratory studies that are taken as fact, that have never actually been confirmed.” 

“Replication studies are rarely funded. No one wants to do them.”

“Too often, a small study with nuanced tentative findings gets blown out of all proportion when it is presented to us, the lay public.”