Meet Seazzadactylus, the newest Late Triassic pterosaur

Dalla Vecchia 2019 introduces us to
Seazzadactylus venirei (Figs. 1–3; MFSN 21545), a small Late Triassic pterosaur known from a nearly complete, disarticulated skeleton (Fig. 2). The tail is supposed to be absent, but enough is there to show it was very gracile. The gracile feet are supposed to be absent, but they were overlooked. The rostrum was artificially elongated, but a new reconstruction (Fig. 3) takes care of that. A jumble of tiny bones in the throat (Fig. 4) were misidentified as a theropod-like curvy ectopterygoid, but the real ectopterygoid fused to the palatine as an L-shaped ectopalatine was identified (Figs. 3,4). 

Figure 1. Seazzadactylus nests between the two Austriadactylus specimens in the LPT.

Figure 1. Seazzadactylus nests between the two Austriadactylus specimens in the LPT.

Seazzadactylus is a wonderful find,
and DGS methodology (Fig. 1) pulled additional data out of it than firsthand observation, which was otherwise quite thorough (with certain exceptions).

Figure 2. Seazzadactylus in situ and tracing from Dalla Vecchia 2019. Colors added here.

Figure 2. Seazzadactylus in situ and tracing from Dalla Vecchia 2019. Colors added here.

Dalla Vecchia reports

  1. The premaxillary teeth are limited to the front half of the bone. Dalla Vecchia did not realize that is so because, like other Triassic pterosaurs, the premaxilla forms the ventral margin of the naris, dorsal to the maxilla (Fig. 3).
  2. A misidentified theropod-like ectopterygoid and pterygoid. Dalla Vecchia should have known no pterosaur has an ectopterygoid shaped like this. Rather the curvy shape represents a jumble of bones (Fig. 4). The real ectopalatine in Seazzadactylus has the typical L-shape (Figs. 3, 4) found in other pterosaurs.
  3. The scapula is indeed a distinctively wide fan-shape.
  4. The proximal caudal vertebrae are present, as are several more distal causals. All are tiny.
Figure 3. Seazzadactylus reconstructed using DGS methods.

Figure 3. Seazzadactylus reconstructed using DGS methods. No such reconstruction was produced by Dalla Vecchia. This is a primitive taxon precocially and by convergence displaying several traits found in more derived taxa.

Figure 4. Seazzadactylus bone jumble, including the L-shaped ectopalatine (orange + tan).

Figure 4. Seazzadactylus bone jumble, including the L-shaped ectopalatine (orange + tan). No pterosaur has a theropod-like ectopterygoid. That’s a loose jumble of bone spurs and shards.

It is easy to see how mistakes were made.
Colors, rather than lines tracing the bones, would have helped. Using a cladogram with validated outgroup taxa and more taxa otherwise were avoided by Dalla Vecchia for reason only he understands.

Figure 5. Seazzadactylus pectoral girdle.

Figure 5. Seazzadactylus pectoral girdle.

Phylogenetically Dalla Vecchia reports,
Macrocnemus bassaniiPostosuchus kirkpatricki and Herrerasaurus ischigualastensis were chosen as outgroup taxa.” (Fig. 6)

Funny thing…
none of these taxa are closely related to each other or to pterosaurs (Macrocnemus the possible distant exception) in the large reptile tree (LRT, 1549 taxa) where no one chooses outgroup taxa for pterosaurs. PAUP makes that choice from 1500+ candidates.

Figure 5. Cladogram by Dalla Vecchia 2019 showing where Seazzadactylus nests

Figure 6. Cladogram by Dalla Vecchia 2019 showing where Seazzadactylus nests. Their is little to no congruence between this cladogram and the LPT (subset Fig. 7), exception in the anurognathids. This cladogram needs about 200 more taxa to approach the number in the LPT.

Within the Pterosauria,
Dalla Vecchia nests his new Seazzadactylus between Austriadraco and Carniadactylus within a larger clade of Triassic pterosaurs that does not include Preondactylus, Austriadactylus or Peteinosaurus. Dalla Vecchia’s cladogram includes 27 taxa (not including the above mentioned outgroup taxa). In the large pterosaur tree (LPT, 239 taxa) Austriadraco (BSp 1994, Fig. 8) is a eudimorphodontid basal to all but two members of this clade. Carniadactylus (Fig. 8) is a dimorphodontid closer to Peteinosaurus. So there is little to no consensus between the two cladograms.

Figure 7. Subset of the LPT focusing on Triassic pterosaurs.

Figure 7. Subset of the LPT focusing on Triassic pterosaurs and their many LRT validated outgroups.

Publishing in PeerJ may cost authors $1400-$1700 (or so I understand).
Dalla Vecchia asked his Facebook friends for monetary help to get this paper published. I offered $900, but only on the proviso that the traditional outgroup taxa (listed above and unknown to me at the time) not be employed. You can understand why I cannot support those invalidated (Peters 2000) outgroups. Dr. Dalla Vecchia’s rejected my offer with a humorless invective of chastisement that likened my offer to one traditionally made by the Mafia. A more polite, ‘no thank-you,’ would have sufficed. Just today I learned of Dalla Vecchia’s ‘chosen’ outgroups. Kids, that’s not good science.

Figure 6. Seazzadactylus sister taxa in the Dalla Vechhia 2019 cladogram to scale.

Figure 8. Seazzadactylus sister taxa in the Dalla Vechhia 2019 cladogram to scale.

Bottom line:
A great new Triassic pterosaur! We’ll hash out the details as time goes by.


References
Dalla Vecchia FM 2019. Seazzadactylus venieri gen. et sp. nov., a new pterosaur (Diapsida: Pterosauria) from the Upper Triassic (Norian) of northeastern Italy. PeerJ 7:e7363 DOI 10.7717/peerj.7363
Peters D 2000a. Description and Interpretation of Interphalangeal Lines in Tetrapods.  Ichnos 7:11-41.
Peters D 2000b. A Redescription of Four Prolacertiform Genera and Implications for Pterosaur Phylogenesis. Rivista Italiana di Paleontologia e Stratigrafia 106 (3): 293–336.

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A new cat-sized flightless azhdarchoid from Canada

Martin-Silverstone, Witton, Arbour and Currie 2019 bring us
news of a humerus and several vertebrae (some fused into a notarium) they taxonomically narrow down to a cat-sized Campanian (Late Cretaceous) azhdarchoid pterosaur. It was found on Hornsby Island, close to the much larger Victoria Island in Southwestern Canada.

The authors report,
“the individual was approaching maturity at time of death.”

In their discussion, the authors state:
“The thin bone walls, gracile bone construction and humeral morphology of RBCM.EH.2009.019.0001, indicate it clearly belonged to a volant Mesozoic animal, a pterosaur or avialan.”

There’s not much to see or reconstruct here.
The few bones found are fragments still in the matrix. The link below will take you to the online PDF.

On closer inspection,
the small triangular deltopectoral crest is smaller than in flightless pterosaurs (e.g. Sos2428 in Fig. 1) and the bone is thicker than one might expect of a volant pterosaur. The authors do not consider the possibility that their specimen had a volant ancestry, but was itself no longer volant, as happens often enough in the azhdarchid line of wading pterosaurs. Some were tiny (Fig. 1), some cat-sized, some man-sized and others much larger. Some were volant. Others were not, convergent with birds of all sizes.

Figure 2. The flightless pterosaur, Sos 2428, along with two ancestral taxa, both fully volant. Note the reduction of the wing AND the expansion of the torso. We don't know the torso of Q. northropi. It could be small or it could be very large.

Figure 1. The flightless pre-azhdarchid pterosaur, Sos 2428, along with two ancestral taxa, both fully volant. Note the reduction of the wing AND the expansion of the torso. This deltopectoral crest is at least twice the size of the new Canadian specimen

Dr. Witton has invested much time and treasure
in telling us giant azhdarchids were volant, despite the facts that weigh against that hypothesis. He also omits the data on three flightless pterosaurs, including Sos2428 (Fig. 1). Now we can add a fourth, his new cat-sized Hornby Island pterosaur.

Earlier co-author Witton
and Habib 2010 discussed hypothetical flightlessness in giant azhdarchids from many angles, but never introduced actual flightless taxa, two of which were known at the time. This online paper included infamous illustrations of an ornithocheirid manus in the process of a quadrupedal launch that had been cheated to implant the wing finger on the substrate, something that never happens according to the ichnite record. They did this by shrinking the free fingers.

Quetzalcoatlus running like a lizard prior to takeoff.

Figure 2. Quetzalcoatlus running like a bipedal lizard with no need or ability to fly.

Postscript
Interesting blog post here on an unfortunate bone misidentification on a paper earlier by one of the co-authors. Thank goodness Witton chose not to vilify his co-author.


References
Martin-Silverstone E, Witton MP, Arbour VM and Currie PJ 2019. A small azhdarchoid pterosaur from the latest Cretaceous, the age of flying giants. Royal Society open science 3: 160333. http://dx.doi.org/10.1098/rsos.160333
Witton MP, Habib MB 2010. On the Size and Flight Diversity of Giant Pterosaurs, the Use of Birds as Pterosaur Analogues and Comments on Pterosaur Flightlessness. PLoS ONE 5(11): e13982. https://doi.org/10.1371/journal.pone.0013982

Fish nibbles on Pteranodon metacarpal

Figure 1. Fish teeth compared to grazed Pteranodon metacarpal

Figure 1. Fish teeth compared to grazed Pteranodon metacarpal

Ehret and Harrell 2018
bring us news from Alabama of two distinct sets of tooth marks on a Pteranodon (Fig. 2) metacarpal (Fig. 1). They report:

“The Pteranodon specimen exhibits serrated teeth marks on the surface of the bone and a second set of larger, unserrated teeth marks unlike those of any contemporary shark species. These feeding traces compare favorably with the tooth spacing and morphology of Squalicorax kaupi, and a small to moderate-sized saurodontid fish, such as Saurodon or Saurocephalus, respectively. In both instances, feeding traces appear to be scavenging events due to the lack of any healing or bone remodeling. The specimen represents a pterosaur that either fell into marine waters or was washed out from nearshore areas and then scavenged by both a chondrichthyan and osteichthyan.”

“Many fossils from late Cretaceous Alabama appear to have been nibbled by sharks, including sea turtles and dinosaurs, which are often ‘covered in predation marks,’ says Ehret.”

NatGeo publicized the find by talking to some pterosaur experts, “Pterosaurs actually had a lot of meat on their skeletons,” says Michael Habib, a pterosaur expert at the University of Southern California who was not involved with the latest find. “They were not the skinny animals often depicted in films and art. The flight muscles in particular would have made a great meal.”

Pterosaur metacarpals,
like all metacarpals, actually are sinewy and have little to no associated muscle.

Habib adds,
“Pteranodon also inhabited this coastal environment during the late Cretaceous, making a living snatching smaller fish from the shark-filled waters. Pterosaurs could float, but being less buoyant than birds, they probably didn’t sit on the surface for long. Some species, including Pteranodon, did likely plunge into the water for prey. “They could then quickly take back off from the surface. But these diving pterosaurs might have been vulnerable to sharks just after they entered the water,” he says.

M. Witton concluded,
“It’s nice to know what species were interacting in this way.”

Ehret corrected the pterosaur experts,
“It’s also possible that the animal died near the shore and was scavenged when it washed out to sea.”

Figure 3. Triebold Pteranodon in floating configuration. Center of balance marked by cross-hairs.

Figure 2 Triebold Pteranodon in floating configuration. Center of balance marked by cross-hairs.

Contra Habib’s statement
Pteranodon was at least as buoyant as a pelican. It has been widely known for over a century that pterosaur bones are thinner than bird bones and Pteranodon metacarpals, in particular, were hollow like pontoons (Fig. 2).

Ultimately
the bite marks represent curiosity, not predation, a point understood by Ehret and Harrell.

References
Ehret DJ and Harrell TL Jr. 2018. Feeding traces of a Pteranodon (Reptilia: Pterosauria) bone from the late Cretaceous (Campanian) Mooreville Chalk in Alabama, USA. Palaios 33(9):414–418.

www.natgeo.com/

Big pterosaurs: big or little wing tips

Earlier and below (Fig. 2) we looked at large and giant pterosaur wings comparing them to the largest flying birds, including one of the largest extant flying birds, the stork, Ciconia, and the extinct sheerwater, Pelagornis, the largest bird that ever flew.

FIgure 2. A basal pteranodotid, the most complete Pteranodon, the largest Pteranodon skull matched to the largest Pteranodon post-crania compared to the stork Ciconia and the most complete and the largest Quetzalcoatlus

FIgure 1. A basal pteranodotid, the most complete Pteranodon, the largest Pteranodon skull matched to the largest Pteranodon post-crania compared to the stork Ciconia and the most complete and the largest Quetzalcoatlus. Note the much reduced distal phalanges in the complete and giant Quetzalcoatlus, distinct from the Pteranodon species.

Today
we’ll look at how the largest Pteranodon (Figs. 1, 4) compares to much larger pterosaurs, like Quetzalcoatlus northropi (Figs. 1, 2) that have vestigial wingtips similar to those of the  much smaller flightless pre-azhdarchid, SOS 2428 (Fig. 3).

Note the tiny three distal phalanges
on the wing of the largest Quetzalcoatlus, distinct from the more typical elongate and robust distal phalangeal proportions on volant pterosaurs of all sizes. Much smaller definitely flightless pterosaurs, like SOS 2428, shrink those distal phalanges, too. That’s the pattern when pterosaurs lose the ability to fly.

Figure 2. Q. northropi and Q. sp. compared to Ciconia, the stork, and Pelagornis, the extinct gannet, to scale. That long neck and large skull of Quetzalcoatlus would appear to make it top heavy relative to the volant stork, despite the longer wingspan. Pteranodon and other flying pterosaurs do not have such a large skull at the end of such a long neck (Fig. 1). The longer wings of pelagornis show what is typical for a giant volant tetrapod, and Q. sp. comes up short in comparison.

Figure 2. A previously published GIF animation. Q. northropi and Q. sp. compared to Ciconia, the stork, and Pelagornis, the extinct gannet, to scale. That long neck and large skull of Quetzalcoatlus would appear to make it top heavy relative to the volant stork, despite the longer wingspan. Pteranodon and other flying pterosaurs do not have such a large skull at the end of such a long neck (Fig. 1). The longer wings of pelagornis show what is typical for a giant volant tetrapod, and Q. sp. comes up short in comparison.Today we’ll compare the wingspan of the largest Quetzalcoatlus to the largest and more typical Pteranodon species (Fig. 2).

Unfortunately
pterosaur workers refuse to consider taxa known to be flightless, like SOS 2428 (Peters 2018). It’s easy to see why they would be flightless (Fig. 3). Scaled to similar snout/vent lengths with a fully volant pterosaur like n42 (BSPG 1911 I 31) the wing length and chord are both much smaller in the flightless form.

Lateral, ventral and dorsal views of SoS 2428

Figure 3. Lateral, ventral and dorsal views of the flightless SoS 2428 (Peters 2018) alongside No. 42, a volant sister taxon.

Comparing the largest ornithocheirid,
SMNK PAL 1136, to the largest Pteranodon (chimaera of largest skull with largest post-crania in Fig. 4) shows that large flyers have elongate distal phalanges, distinct from body and wing proportions documented in the largest azhdarchids, like Quetzalcoatlus.

Figure 5. Largest Pteranodon to scale with largest ornithocheirid, SMNS PAL 1136.

Figure 4. Largest Pteranodon to scale with largest ornithocheirid, SMNS PAL 1136. Note the long distant wing phalanges on both of these giant flyers. This is what pterosaurs evolve to if they want to continue flying. And this is how big they can get and still fly. Giant azhdarchids exceed all the parameters without having elongate wings. Note: the one on the left has a longer wingspan whir the one on the right has a more massive torso and skull together with more massive proximal wing bones and pectoral girdle. On both the free fingers are tiny, parallel oriented laterally and slightly tucked beneath the big knuckle of the wing finger. The pteroid points directly at the deltopectoral crest. 

As the largest Pteranodon and largest ornithocheirid (SMNS PAL 1136)
(Fig. 4) demonstrate, as flying pterosaurs get larger, they retain elongate distal wing phalanges. And big, robust phalanges they are.

By contrast in azhdarchids and pre-azhdarchids
there is a large size bump after n42 (BSPG 1911 I 31) the fourth wing phalanx either disappears (see Microtuban and Jidapterus) or shrinks to a vestige. Then there’s Zhejiangopterus (Fig. 5), with a big pelvis, gracile forelimbs and a giant skull on a very long neck. Just that neck alone creates such a long lever arm that the pterosaur is incapable of maintaining a center of balance over or near the shoulder joints.

Figure 1. Click to enlarge. There are several specimens of Zhejiangopterus. The two pictured in figure 2 are the two smallest above at left. Also shown is a hypothetical hatchling, 1/8 the size of the largest specimen.

Figure 5. There are several specimens of Zhejiangopterus. The two pictured in figure 2 are the two smallest above at left. Also shown is a hypothetical hatchling, 1/8 the size of the largest specimen.

As mentioned earlier, becoming flightless permitted, nay, freed azhdarchid pterosaurs to attain great size. They no longer had to maintain proportions that were flightworthy. Instead they used their shortened strut-like forelimbs to maintain a stable platform in deeper waters. And when they had to move in a hurry, their wings could still provide a tremendous amount of flurry and thrust (Fig. 6) for a speedy getaway.

Quetzalcoatlus running like a lizard prior to takeoff.

Figure 6. Quetzalcoatlus running without taking off, using all four limbs for thrust. That long lever arm extending to the snout tip in front of the center of gravity is not balanced in back of what would be the center of lift over the wings

For the nitpickers out there…
some specimens of Nyctosaurus (UNSM 93000, Fig. 7) also have but three wing phalanges, but they are all robust. The distal one is likely the fourth one because it remains curved. Phalanges 2 and 3 appear to have merged, or one of those was lost. Compare that specimen to a more primitive Nyctosaurus FHSM VP 2148 with four robust wing phalanges.

Figure 5. Cast of the UNSM 93000 specimen of Nyctosaurus. Missing parts are modeled here.

Figure 5. Cast of the UNSM 93000 specimen of Nyctosaurus. Missing parts are modeled here.

References
Peters D 2018. First flightless pterosaur (not peer-reviewed). PDF online.

 

Flugsaurier 2018: ‘Young istiodactylid’ nests with tall pterodactylids in the LPT

Flugsaurier 2018 opens today, August 10,
and the abstract booklet is out. So it’s time to take a look at some of the news coming out of that Los Angeles pterosaur symposium. Since the purpose of the symposium is increase understanding of pterosaurs, I hope this small contribution helps.

Figure 1. The Erlianhaote specimen attributed by Hone and Xu 2018 to istiodactylidae nests in the LPT with the large derived pterodactylids.

Figure 1. The Erlianhaote specimen attributed by Hone and Xu 2018 to the clade Istiodactylidae (within Ornithocheiridae) nests in the LPT with the large derived pterodactylids. Note the un-warped deltopectoral crest and lack of a deep cristospine, along with the long legs and short wings.

Hone and Xu at Flugsaurier 2018
describe, “An unusual and nearly complete young istiodactylid from the Yixian Formation, China (Fig. 1). The specimen shows the characteristic istiodactylid cranial features of tooth shape and enlarged nasoantorbital fenestra. However, it has proportionally large hindlimbs and wing proportions that are similar to those of azhdarchids. This has led to suggestion that the specimen may be a composite and that only the cranial material is istiodactylid. Preparation work around some key parts revealed no inconsistencies in the matrix or evidence of glue. The specimen is held in the Erlianhaote Dinosaur Museum, Erlianhote, China.”

Figure 2. The Erlianhaote specimen nests with these pterodactylids in the LPT, not with Istiodactylus (Fig. 3).

Figure 2. The Erlianhaote specimen nests with these pterodactylids in the LPT, not with Istiodactylus (Fig. 3). Note the antorbital fenestra becomes longer with larger size in this clade. The teeth are similar to those in istiodactylids.

Reconstructed as is
(Fig. 2) and added to the large pterosaur tree (LPT, 233 taxa, not yet updated due to no museum number nor genus name) the young ‘istiodactylid’ nests as a large derived pterodactylid. 13 steps separate this taxon from the Istiodactylus clade.

Ornithocheirids,
like Istiodactylus (Figs. 3, 4) and the SMNL PAL 1136 specimen (Fig. 5), share a very large wing finger, a short metacarpus, a warped deltopectoral crest, small free fingers and deeply keeled sternal complex not found in the Erlianhote specimen.

Figure 3. Istiodactylus has a shorter neck, longer wing finger and deep cristospine, among other traits not found in the new Erlianhaote specimen.

Figure 3. Istiodactylus has a shorter neck, longer wing finger and deep cristospine, among other traits not found in the new Erlianhaote specimen.

Figure 4. Istiodactylus sinensis is an istiodactylid from China sharing few traits with the new Erlianhaote specimen. Note the warped deltopectoral crest not warped in the new specimen.

Figure 4. Istiodactylus sinensis is an istiodactylid from China sharing few traits with the new Erlianhaote specimen. Note the warped deltopectoral crest not warped in the new specimen. Manual 4.1 is shorter than in other well-known istiodactylids.

The largest ornithocheirid

Figure 5. The unnamed largest ornithocheirid, SMNK PAL 1136, nests with Istiodactylus.

Figure 6. The Erlianhaote pterodactylid reconstructed in several views.

Figure 6. The Erlianhaote pterodactylid reconstructed in several views. The imagined (gray) areas of the skull here were imagined as an istiodactylid, but the better restoration is shown in figure 2.

It’s better not to eyeball certain specimens.
Sometimes you have to run them through a phylogenetic analysis to find out what they are. That’s what the LPT is for. It minimizes taxon exclusion and handles convergence.

Pterosaurs are still lepidosaurs.
So they follow lepidosaur fusion patterns, which follow phylogeny. Hone and Xu made the mistake of imagining pterosaurs might have archosaur fusion patterns that follow ontogeny.

Why am I not at Flugsaurier 2018?
In addition to about a dozen reasons that I can list later, or your can guess now, I can be more helpful and timely here.

References
Andres B and Ji Q 2006. A new species of Istiodactylus (Pterosauria, Pterodactyloidea) from the Lower Cretaceous of Liaoning, China. Journal of Vertebrate Paleontology, 26: 70-78.
Bowerbank JS 1846. On a new species of pterodactyl found in the Upper Chalk of Kent P. giganteus). Quarterly Journal of the Geological Society 2: 7–9.
Bowerbank JS 1851. On the pterodactyles of the Chalk Formation. Proceedings of the Zoological Society, London, pp. 14–20 and Annals of the Magazine of Natural History (2) 10: 372–378.
Bowerbank JS 1852. On the pterodactyles of the Chalk Formation. Reports from the British Association for the Advancement of Science (1851): 55.
Hone DWE and Xu 2018. An unusual and nearly complete young istiodactylid from the Yixian Formation, China. Flugsaurier 2018: the 6th International Symposium on Pterosaurs. Los Angeles, USA. Abstracts: 53–56.
Hooley RW 1913. On the skeleton of Ornithodesmus latidens. An ornithosaur from the Wealden shales of Atherfield (Isle of Wight)”, Quarterly Journal of the Geological Society, 69: 372-421
Howse SCB, Milner AR and Martill DM 2001. Pterosaurs. Pp. 324-335 in: Martill, D. M. and Naish, D., eds. Dinosaurs of the Isle of Wight, The Palaeontological Association
Wang X, Rodrigues T, Jiang S, Cheng X and Kellner AWA 2014. An Early Cretaceous pterosaur with an unusual mandibular crest from China and a potential novel feeding strategy. Scientific Reports 4 : 6329, pp. 1-9. | DOI: 10.1038/srep06329
Witton MP 2012. New Insights into the Skull of Istiodactylus latidens (Ornithocheiroidea, Pterodactyloidea). PLoS ONE 7(3): e33170. doi:10.1371/journal.pone.0033170

wiki/Istiodactylus

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

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