The Times (UK) declares: proof for ‘winged dinosaurs’ vaulting

According to The Times.co.uk,
“Isle of Wight find proves winged dinosaurs took off by ‘vaulting’ into the air. Following the discovery of a fossilised giant pterosaur, scientists may have resolved how the 650lb beasts took flight. The sheer size of such creatures has long baffled scientists because they seem too heavy to take off. Now research with a computerised 3D model suggests they used their massive leg and wing muscles to catapult themselves into the air.”

Figure 1. Image from The Sunday Times (UK) showing the Isle of Wight and an ornithocheird filled with helium on a smaller planet taking off by vaulting.

Figure 1. Image from The Sunday Times (UK) showing the Isle of Wight and an ornithocheird filled with helium on a smaller planet taking off by vaulting. See figure 2 for the 650 lb Hatzegopteryx. The human silhouette (gray at left) is way too small for this ornithocheirid, so they got their pterosaurs mixed-up.

“Robert Coram, a professional fossil hunter who made the find, said: “It might have been the largest flying creature that had ever lived up to that time.”

“Mr Habib explained: “Mathematical modelling indicates that launching from a quadrupedal stance — pushing off first with the hind limbs and then with the forelimbs — would have provided the leaping power giant pterosaurs required for takeoff.”

FIgure 2. From The Sunday Times (UK) showing a human to scale with a restoration of Hatzegopteryx.

FIgure 2. From The Sunday Times (UK) showing a human to scale with a restoration of Hatzegopteryx.

This article appears to follow a Witton 2019 SVPCA abstract
(coincidence?) discussing the flight capabilities of the giant azhdarchid, Hatzegopteryx, using Graphic Double Integration and Principal Component Analysis. AND this article coincides with a Scientific American cover story on pterosaurs by Dr. Habib, discussed earlier here.

The pterosaur experts talking to The Times are still not discussing
the much smaller phylogenetic ancestors of azhdarchids with longer wings, nor do they consider the reduced to vestigial distal phalanges that essential clip the wings of azhdarchids over 1.8 m (6 ft) tall, nor do they recognize the traits that attend small flightless pterosaurs.

Let’s stop promoting giant volant pterosaurs
until these objections are met and resolved. Perhaps a little backtracking and apologizing for earlier grand standing is in order here.

Figure 1. Estimating giant azhdarchid weight from estimated height and comparables with similar smaller taxa.

Figure 3. Estimating giant azhdarchid weight from estimated height and comparables with similar smaller taxa.

Let’s define giant pterosaurs
as those at least 2m or 7ft tall at the eyeball (sans crest if present). The rest are large (more or less human-sized) pterosaurs (comparable to Pelagornis, Fig. 4) or smaller pterosaurs comparable to some other extant bird (e.g. goose-, robin- or hummingbird-sized).

Figure 1. Click to enlarge. The largest flying and non-flying birds and pterosaurs to scale.

Figure 4. Click to enlarge. The largest flying and non-flying birds and pterosaurs to scale.

You might remember
an earlier post featuring a classified ad from U of Leicester, (UK) seeking a student to prove the vaulting pterosaur hypothesis by finding appropriate pterosaur tracks. The Isle of Wight includes several strata with dinosaur tracks. Perhaps someday they will deliver giant pterosaur tracks that suddenly end. Then we can argue if the pterosaur flew from that point on and how it did so.


References
Witton M 2019. You’re going to need a bigger plane: body mass and flight capabilities of the giant pterosaur. SVPCA abstracts.
Counter arguments based on facts appear here:

New PBS Eons video: How pterosaurs got their wings

The good folks at PBS Eons
added a new video on the origin of pterosaurs. The following repeats (with added images) my comments on the PBS Eons video on YouTube.

This video is SO WRONG
so many times. The origin of pterosaurs is not ‘foggy.’

The Scleromochlus (Fig. 1) hypothesis for pterosaur origins was invalidated by Peters 2000 who tested it and all other candidates for pterosaur origins in four separate phylogenetic analyses by adding taxa to prior studies. Macrocnemus, Langobardisaurus, Cosesaurus, Sharovipteryx and Longisquama (Fig. 2) were recovered closer to pterosaurs.
Figure 3. Short-legged Gracilisuchus, along with sisters, long-legged bipedal Pseudhesperosuchus and Scleromochlus.

Figure 1. Short-legged Gracilisuchus, along with sisters, long-legged bipedal Pseudhesperosuchus and Scleromochlus.

Scleromochlus nested with basal bipedal crocodylomorphs,
(Fig. 1) close to the origin of dinosaurs. Note the tiny hands on Scleromochlus. Note the lack of pedal digit 5 on Scleromochlus. By contrast, pterosaurs had large hands and a specialized pedal digit 5 that had two large phalanges that folded together such that the distal phalanx was dorsal side down, making an impression behind pedal digits 1–4 (Figs. 10, 11). More on this below.
Figure 3. The origin of pterosaurs now includes Kyrgyzsaurus, nesting between Cosesaurus and Sharovipteryx.

Figure 2. The origin of pterosaurs now includes Kyrgyzsaurus, nesting between Cosesaurus and Sharovipteryx. Click to enlarge.

Pterosaurs didn’t fossilize very well?
False. Look at all the excellent pterosaur fossils we know of, some with soft tissue.
Pterosaurs are not archosaurs.
Peters 2000 introduced the clade Fenestrasauria for pterosaurs + their above named ancestors. These in turn were part of a new clade of lepidosaurs, named Tritosauria, nesting between Rhynchocephalians and Protosquamates published in Peters 2007.
Cosesaurus and Longisquama have extra-large fingers,
dominated by digit 4. See: http://reptileevolution.com/pterosaur-wings.htm
Ornithodirans are a junior synonym
for Reptilia (=Amniota, see cladogram link below). Not wise to bring up this invalidated clade name.
Figure 1. Scaphognathians to scale. Click to enlarge.

Figure 3. Scaphognathians to scale. Click to enlarge.

The pterodactyloid grade of pterosaur
was attained four times by convergence (two from the genus Dorygnathus, two more from the genus Scaphognathus, Fig. 3). Transitional taxa were all tiny Solnhofen forms (Fig. 3). As in many other clades, phylogenetic miniaturization attended the genesis of derived pterosaurs.
As in giant birds,
Quetzalcoatlus (Fig. 4) grew so large because it was flightless. All azhdarchids over six-feet-tall had clipped wings (vestigial distal wing phalanges) good for flapping and walking on, not for flying.
Figure 1. Estimating giant azhdarchid weight from estimated height and comparables with similar smaller taxa.

Figure 4. Estimating giant azhdarchid weight from estimated height and comparables with similar smaller taxa.

No pterosaur fossils had wing membranes extending ‘the length of their legs’.
All soft tissue shows the short chord wing membrane was stretched between the elbow and wing tip.  See: http://reptileevolution.com/pterosaur-wings.htm
Tritosaur pectoral girdles demonstrating the evolution and migration of the sternal elements to produce a sternal complex.

Figure 5. Tritosaur pectoral girdles demonstrating the evolution and migration of the sternal elements to produce a sternal complex.

How did pterosaurs get their wings? 
Convergent with theropods ancestral to birds, Cosesaurus reorganized its pectoral girdle to flap (Fig. 5). The scapula became immobile and strap-like. The coracoid became immobile and stalk-like. The clavicles, interclavicle and single sternum migrated together, then fused together. The forelimbs of Cosesaurus were too short for flight, but fully capable of flapping, probably as a mating ritual. Likewise the pectoral girdles of Sharovipteryx and Longisquama were similarly built. Of the three, Longisquama had the largest hands, but still could not fly. Bergamodactylus was the basalmost pterosaur and it could fly. See links below.
Why guess how a hypothetical ancestor learned to fly
when we have excellent samples of every stage? (see links below)
The arboreal leaping model
does not require flapping — and gliders do not evolve into flappers (e.g. colugos, squirrels, sugar gliders, etc.)
The arboreal parachute model
worked for bats, but they were seeking prey beneath their perches as fingers 3-5 then 2-5 elongated. Pterosaurs only elongated one digit: #4. It made a better wing than bug-in-the-leaf-litter trap.
The terrestrial model
is Lamarckian, growing bigger wings to catch insects just out of reach for most is not good science.
Figure 5. Cosesaurus forelimb with pro to-aktinofibrils trailing the ulna.

Figure 6. Cosesaurus forelimb with pro to-aktinofibrils trailing the ulna.

Sexy
The valid hypothesis for bird and pterosaur wing evolution is competitive attractiveness during mate selection (think birds-of-paradise) with cosesaur-like creatures flapping and displaying. BTW, both Cosesaurus and Longisquama are preserved with membranes trailing finger 4, (Fig. 6) which folds in the plane of the wing in Longisquama (Fig. 7).

Figure 7. Click to enlarge. The origin of the pterosaur wing and the migration of the pteroid and preaxial carpal. A. Sphenodon. B. Huehuecuetzpalli. C. Cosesaurus. D. Sharovipteryx. E. Longisquama. F-H. The Milan specimen MPUM 6009, a basal pterosaur.

Not to be outdone,
Sharovipteryx (Fig. 8) had membranes (uropatagia) trailing each hind limb. These are reduced in pterosaurs, which continue to use their hind limbs as horizontal stabilizers, their feet as twin rudders, as the flapping forelimbs, closer to the center of gravity, become ever larger, better for display, then for short flapping hops, then for flight.
Figure 3. Sharovipteryx reconstructed. Note the flattened torso.

Figure 8. Sharovipteryx reconstructed. Note the flattened torso.

Another false statement corrected here:
The scapula of Scleromochlus (Fig. 1) was tiny. It only had to support a tiny forelimb with vestigial fingers.
Scleromochlus had a ‘square pelvis’
because it, too was a biped. But that was nothing compared to the larger pelvis of Cosesaurus (Fig. 9), which also had a prepubis, a pterosaurian trait not found on Scleromochlus. The pelvis of Sharovipteryx was larger still.
Figure 1. Cosesaurus flapping - fast. There should be a difference in the two speeds. If not, apologies. Also, there should be some bounce in the tail and neck, but that would involve more effort and physics.

Figure 9. Cosesaurus flapping. Tere should be some bounce in the tail and neck, but that would involve more effort and physics.

Scleromochlus had a long muscular tail.
As in crocs and dinos, and most reptiles, the caudofemoral muscles were pulling the femur. Compare that with the attenuated tail of pterosaurs, Cosesaurus and Sharovipteryx. Only pelvic muscles were pulling the femur.
Back legs longer than front legs in Scleromochlus?
That’s what we also see in Cosesaurus, Sharovipteryx and Longisquama.
Cosesaurus and Rotodactylus, a perfect match.

Figure 10. Cosesaurus and Rotodactylus, a perfect match. Elevate the proximal phalanges along with the metatarsus, bend back digit 5 and Cosesaurus (left) fits perfectly into Rotodactylus (right).

Walking on its toes?
We have Rotodactylus ichnites (hand and footprints, Figs. 10, 11) that match Middle Triassic Cosesaurus in the Early Triassic. These include the impression of pedal digit 5 behind toes 1-4. Nothing else like them in the fossil record.
True!
Scleromochlus was like the modern jerboa, with its tiny vestigial hands, totally inappropriate as a pterosaur ancestor.
False!
Not all pterosaur tracks are quadrupedal. Only derived pterosaurs, those that frequented beaches were. We have bipedal pterosaur tracks (Fig. 12). See references below.
Cosesaurus foot in lateral view matches Rotodactylus tracks.

Figure 11. Cosesaurus foot in lateral view matches Rotodactylus tracks.

Quadrupedality in pterosaurs is secondary.
Note the backward pointing manual digit 3 in quad tracks. Note the fusion of four to thirteen sacrals into a sacrum and the elongation of the ilium to anchor large femoral muscles and anchor the increasingly larger sacrum in all pterosaurs. In order to flap, you have to be a biped.
Figure 1. Pteraichnus nipponensis, a pterosaur manus and pes trackway, matched to n23, ?Pterodactylus kochi (the holotype), a basal Germanodactylus.

Figure 12. Pteraichnus nipponensis, a pterosaur manus and pes trackway, matched to n23, ?Pterodactylus kochi (the holotype), a basal Germanodactylus.

All quad pterosaurs can be attributed to pterodactyloid-grade pterosaurs,
those that underwent phylogenetic miniaturization during the Jurassic. At that time, the fly-size hatchlings of the hummingbird-sized adults (Fig. 13) could not leave the moist leaf litter or risk desiccation until growing to a sufficient size. So they walked around on all fours until attaining flight size.
A hypothetical hatchling No. 6

Figure 2. A hypothetical hatchling No. 6 alongside a fly, a flea and the world’s smallest insect, a fairy fly (fairy wasp). The fairy wasp is shown enlarged here (scaled in red) and in figure 1.

True!
The extinction of pterosaurs can be attributed to their great size at the end of the Cretaceous. They had no tiny representatives, like they did at the end of the Jurassic, to weather the rapid climate changes and/or seek shelter.

References

For a cladogram that documents the family tree of pterosaurs see: http://ReptileEvolution.com/MPUM6009-3.htm
For a cladogram that documents pterosaur and dinosaur ancestors back to Silurian jawless fish see: http://ReptileEvolution.com/reptile-tree.htm
For fossils and reconstructions of pterosaur ancestors, see:
And here are all the peer-reviewed academic publications
that some pterosaur experts don’t want to talk about:
Peters D 2000a. A Redescription of Four Prolacertiform Genera and Implications for Pterosaur Phylogenesis. Rivista Italiana di Paleontologia e Stratigrafia 106 (3): 293–336.
Peters D 2000b. Description and Interpretation of Interphalangeal Lines in Tetrapods.  Ichnos 7:11-41.
Peters D 2002. A New Model for the Evolution of the Pterosaur Wing – with a twist. Historical Biology 15: 277-301.
Peters D 2007. The origin and radiation of the Pterosauria. In D. Hone ed. Flugsaurier. The Wellnhofer pterosaur meeting, 2007, Munich, Germany. p. 27.
Peters D 2011. A Catalog of Pterosaur Pedes for Trackmaker Identification. Ichnos 18(2):114-141.

Pterorhynchus dewlap now looks like a displaced wing membrane

Short one today
on an old subject: the apparent dewlap of the pterosaur Pterorhynchus (Fig. 1).

Figure 1. Pterorhynchus under UV light. Given that no sisters have such a dewlap, this now looks like a displaced wing membrane, as in Sordes.

Figure 1. Pterorhynchus under UV light. Given that no sisters have such a dewlap, this now looks like a displaced wing membrane, as in Sordes.

Now it looks like a displaced wing membrane.
We’ve seen this before with Sordes. Sorry this took so long to appreciate and understand. The proximity to the throat bends the mind that way. Those wing fibers are impressive in UV.


References
Czerkas SA and Ji Q 2002. A new rhamphorhynchoid with a headcrest and complex integumentary structures. In: Czerkas SJ ed. Feathered Dinosaurs and the Origin of Flight. The Dinosaur Museum:Blanding, Utah, 15-41. ISBN 1-93207-501-1.

wiki/Pterorhynchus

Fresh data on little Ningchengopterus (not a baby pterosaur)

Yesterday we looked at a new paper on an old topic,
the ability of ‘large enough’ pterosaur hatchlings to fly shortly after hatching (Unwin and Deeming 2019). I say, ‘large enough’ because some fly-sized hatchlings of hummingbird-sized adults were not large enough to avoid desiccation due to their high surface/volume ratio. This was likely the origin of quadrupedal locomotion from bipedal pterosaur ancestors. Such tiny hatchlings had to remain within high humidity leaf litter environs until reaching that minimum size for flight. And they probably drank a lot of water.

On the publicity tour for Unwin and Deeming 2019,
the NYTimes.com published an article that contained a rather high-resolution picture of a small Late Jurassic pterosaur, Ningchengopterus (Figs. 1-3; Lü 2009) that is several magnitudes better than the originally published line drawing.

Figure 1. ?Ningchengopterus in situ. Note the narrow-at-the-elbow wing membrane and manual digit 5 near the wrist.

Figure 1. ?Ningchengopterus in situ. Note the narrow-at-the-elbow wing membrane and manual digit 5 near the wrist. There is no wing membrane connection to the lower leg or ankle, only a ‘fuselage fillet’ inside the elbow.

Ningchengopterus? liuae (Lü J 2009) CYGB-0035 was originally considered a “baby”, even though it had an adult crest. Here, in the large pterosaur tree (LPT, 238 taxa) Ningchengopterus was derived from a sister to the larger Painten pterosaur and it phylogenetically preceded Pterodactylus antiquus? AMNH 1942 (No. 20 in Wellnhofer (1970). Here it appears that Ningchengopterus was actually a basal Pterodactylus and therefore congeneric.

Despite the additional data and several scoring changes,
the nesting of Ningchengopterus in the LPT did not change. So crappy data sometimes work. Crappy character lists sometimes work. Taxon exclusion never works. Let’s treat every pterosaur specimen as a taxon, like the LPT does, and see which taxa are associated with many times larger adults… and which nest with other tiny pterosaurs under phylogenetic miniaturization.

Figure 2. Ningchenopterus reconstructed using DGS methods. Sure it's small, but not much smaller than sister taxa after phylogenetic analysis.

Figure 2. Ningchenopterus reconstructed using DGS methods. Sure it’s small, but not much smaller than sister taxa after phylogenetic analysis.

Ningchengopterus preserves a complete proximal wing membrane
(Fig. 1) that confirms the findings of Peters 2002, in which evidence for a narrow chord pterosaur wing membrane that was stretched between the elbow and wing tip was presented for all pterosaurs in which the soft tissue is preserved, distinct from traditional bat-wing models proposed without evidence by several PhDs.

Figure 3. Finger 5 in Ningchengopterus is very clear, but overlooked by all other pterosaur workers.

Figure 3. Finger 5 in Ningchengopterus is very clear, but overlooked by all other pterosaur workers.

Manual digit 5 on pterosaurs is a vestige
(Fig. 3) that has been overlooked by all prior pterosaur workers. Ningchengopterus preserves manual digit 5 without question.

Figure 6. The Painten pterosaur phylogenetically nests between two smaller specimens in the LPT. 

Figure 4. The Painten pterosaur phylogenetically nests between two smaller specimens in the LPT. This is an earlier reconstruction of Ningchengopterus.

We’ve already established
(contra tradition enforced by several pterosaur professors) that pterosaur hatchlings were nearly identical to their 8x larger adults. So how do we determine if a pterosaur is a hatchling or an adult? The answer is phylogenetic analysis. A small adult pterosaur will nest with other small adult pterosaurs. A juvenile will nest with much larger adult pterosaurs, as demonstrated here with the first juvenile Rhamphorhynchus recovered by phylogenetic analysis, a paper the pterosaur referees did not want you to read, but you can read it here at ResearchGate.net for yourself.

Figure 1. Large anurognathids and their typical-sized sisters. Here the IVPP embryo enlarged to adult size is larger than D. weintraubi and both are much larger than more typical basal anurognathids, Mesadactylus and MCSNB 8950.

Figure 5. Large anurognathids and their typical-sized sisters. Here the IVPP embryo enlarged to adult size is larger than D. weintraubi and both are much larger than more typical basal anurognathids, Mesadactylus and MCSNB 8950.

There is (so far) only one exception to the above rule:
The IVPP anurognathid embryo (Fig. 5) is the same size as several adult sister taxa, like MCSNB 8950 and Mesadactylus. So undiscovered adults will be giant basal anurognathids when found. One incomplete and mislabeled sister taxon, ?Dimorphodon weintraubi, is closer in size to the hypothetical adult of the IVPP embryo, demonstrating the possibility of a giant anurognathid is real. Again, phylogenetic analysis works out all such problems.

The Vienna Pterodactylus.

Figure 6. The Vienna Pterodactylus. Click to animate. Wing membranes in situ (when folded) then animated to extend them. There is no shrinkage here or in ANY pterosaur wing membrane. There is only an “explanation” to avoid dealing with the hard evidence here and elsewhere.


References
Lü J 2009. A baby pterodactyloid pterosaur from the Yixian Formation of Ningcheng, Inner Mongolia, China. Acta Geologica Sinica 83 (1): 1–8.
Peters D 2002. A New Model for the Evolution of the Pterosaur Wing – with a twist. – Historical Biology 15: 277–301.
Unwin DM and Deeming DC 2019. Prenatal development in pterosaurs and its implications for their postnatal locomotory ability. Proceedings of the Royal Society B https://doi.org/10.1098/rspb.2019.0409

wiki/Ningchengopterus

Digitally boosting contrast to better see pterosaur wings

With all the new innovations
in seeing otherwise invisible details using UV, RTI, laser and fluorescing lighting, let’s not forget that Adobe Photoshop can boost contrast after the original digital photograph has been taken. In the present example (Figs. 1-4), the wing membrane is ever so slightly darker than the matrix, but that small range can be increased digitally.

Figure 1. The proximal wing of TMP 2008.41.001 showing original photo, original tracing along with boosted contrast and color tracing.

Figure 1. The proximal wing of TMP 2008.41.001 showing original photo, original tracing along with boosted contrast and color tracing. Nothing changes here, except the interpretation. I say this is data. Hone et al. 2015 wrongly call this ‘shrinkage’. Where is the pteroid? I would X-ray this slab. Based on the propatagium, it is probably buried.

Earlier we looked at
the TMP  2008.41.0001 specimen of Rhamphorhynchus (Hone et al.  2015). Today we’ll just rotate the images to fit the taller-than-wide blogspace format and digitally boost the contrast of the published photos to see what we can see together. Hon et al. traced the same wing membrane borders. Then they said it was ‘fake news’ due to ‘shrinkage’, but only where they wanted it to ‘shrink’.

Figure 3. Right wing and tail of the TM 2008.41.0001 specimen with contrast digitally boosted. Labels and line art from Hone et al. 2016.

Figure 2. Right wing and tail of the TM 2008.41.0001 specimen with contrast digitally boosted. Labels and line art from Hone et al. 2016.

Despite the fact
that this specimen documents a narrow-chord wing membrane stretched between the elbow and wingtip (Fig. 1), no citation to Peters 2002 was provided by Hone et al. 2016, thus fulfilling Bennett’s curse, “You won’t get published and if you do get published, you won’t get cited.”

As readers already know
Dr. David Hone deleted all reference to Peters 2000 when testing the minority view on pterosaur origins (from fenestrasaurs, Peters 2000) versus the majority view (from archosaurs, Bennett 1996), then ascribing both views to Bennett (1996) in a series of two papers (Hone and Benton  2007, 2009) discussed earlier here.

According to Hone et al. (2016):
“Each wing has a more narrow chord along  most of its length than seen in some specimens of Rhamphorhynchus (e.g., BSPG 1938 I 503a, the ‘DarkWing’ specimen—Frey et al., 2003) suggesting some postmortem shrinkage of the membranes (Elgin, Hone & Frey, 2011).”

Unfortunately,
Hone et al did not realize they were looking at a patch of mid-wing membrane in the DarkWing specimen (Fig. 4). We looked at the pre- and post-mortem disarticulation of the ‘DarkWing specimen earlier here.

Of course,
the authors did not forget to cite their own study on wing shape, Elgin, Hone & Frey 2011, in which they considered all examples of a narrow chord wing membrane (that means all examples) caused due to taphonomic ‘shrinkage.’ Their zeal for re-imagining hard data was reviewed earlier here and here.

Figure 2. Left wing of TMP 2008.41.001 showing original photo, original tracing along with boosted contrast and color tracing. Wing tip includes apparently missing wingtip ungual, but there is an articular surface there.

Figure 3. Left wing of TMP 2008.41.001 showing original photo, original tracing along with boosted contrast and color tracing. Wing tip includes apparently missing wingtip ungual, but there is an articular surface there and the membrane extends beyond m4.4.

The wing tip was twisted during burial
rotating the distal elements 180º. This was misinterpreted by Hone and Elgin in their report of the small rhamphorhychid, Bellubrunnus, in which they claimed this was the natural orientation of the wing tip elements in Bellubrunnus. We looked at that unfortunate interpretation earlier here.

Figure 1. The darkwing specimen of Rhamphorhynchus. Top: in situ. Middle: Soft tissues highlighted. Bottom: Neck and forelimb restored.

Figure 4. The darkwing specimen of Rhamphorhynchus. Top: in situ. Middle: Soft tissues highlighted. Bottom: Neck and forelimb restored to the invivo position. Note: the proximal portion is not exposed in situ.  The purple line is drawn based on phylogenetic bracketing. All other pterosaurs have a narrow chord wing membrane.

It is not good for paleontology
when workers ignore hard data.

The Zittel wing

Figure 5. The Zittel wing from a species of Rhamphorhynchus. Click to enlarge. Elgin, Hone and Frey 2011 dismissed this specimen as another example of ‘shrinkage’, but only where they wanted it to shrink.

The other question you should ask,
is why professional paleontologists, PhDs and professors are not calling attention to such issues? It is not good for paleontology when a civilian scientist has to point out such errors of judgement…over and over. Your paleontologists are imagining ‘shrinkage’ wherever they want to and not elsewhere, for some strange reason. Imagine their worst nightmare… backing away from their imaginary interpretations as they begrudgingly accept reality.

IF there was even ONE example
of a pterosaur wing membrane attached at the ankles, I would be the first to tell you about it. So far, all evidence purporting to do so, like the infamous Sordes holotype, has been soundly and thoroughly debunked. Please tell that to the authors listed below, plus any other artists and PhDs who need to know.


References
Elgin RA, Hone DWE and Frey E 2011. The extent of the pterosaur flight membrane. Acta Palaeontologica Polonica 56 (1), 2011: 99-111. doi: 10.4202/app.2009.0145
Hone D, Henderson DM, Therrien F and Habib MB 2015. A specimen of Rhamphorhynchus with soft tissue preservation, stomach contents and a putative coprolite. PeerJ 3:e1191; DOI 10.7717/peerj.1191
Peters D 2002. A New Model for the Evolution of the Pterosaur Wing – with a twist. – Historical Biology 15: 277–301.

https://pterosaurheresies.wordpress.com/2011/11/03/what-the-dark-wing-rhamphorhynchus-tells-us/

 

Vestigial fingers on the UNSM 93000 Nyctosaurus

The UNSM 93000 specimen attributed to Nyctosaurus
has only three wing phalanges and the tiny vestigial free fingers have never been looked at using DGS methods before. Well, here they are (Fig. 1).

Figure 1. Closeup of the UNSM 93000 specimen of Nyctosaurus focusing on three vestige free fingers.

Figure 1. Closeup of the UNSM 93000 specimen of Nyctosaurus focusing on three vestige free fingers. This is what happens when you no longer need these fingers. You can tell Nyctosaurus from Pteranodon in that the former never fuses the sesamoid (extensor tendon process) to phalanx 4.1. Other wrongly consider this a trait of immaturity.

Nyctosaurus sp. UNSM 93000 (Brown 1978, 1986) was derived from a sister to Nyctosaurus gracilis and phylogenetically preceded the crested Nyctosaurus specimens. Except for the rostral tip, the skull and cervicals are missing. Distinct from Nyctosaurus gracilis, the dorsals of the Nebraska specimen relatively shorter. The scapula and coracoid were more robust. The deltopectoral crest of the humerus most closely resembled that of Muzquizopteryx. Fingers I-III were tiny vestiges. Manual 4.1 extended to mid ulna when folded. Manual 4.4 was probably fused to m4.3 or it was missing and m4.3 became curved.

Figure 1. The UNSM specimen of Nyctosaurus, the only one for which we are sure it had only three wing phalanges.

Figure 2. The UNSM specimen of Nyctosaurus, the only one for which we are sure it had only three wing phalanges.

The pubis and ischium did not touch, as in more primitive nyctosaurs. It would have been impossible for the forelimb to develop thrust during terrestrial locomotion. It was likely elevated or used like a ski-pole.


The family tree of the Ornithocephalia and Germanodactylia is here. The expanded family tree of the Pterosauria is here.


References
Brown GW 1978. Preliminary report on an articulated specimen of Pteranodon Nyctosaurusgracilis. Proceedings of the Nebraska Academy of Science 88: 39.
Brown GW 1986. Reassessment of Nyctosaurus: new wings for an old pterosaur. Proceedings of the Nebraska Academy of Science 96: 47.

 

Scaphognathus wing membrane in visible light

Today a paper by Jäger et al. 1831
put the holotype of Scaphognathus (Goldfuß 1831; Late Jurassic) under various forms of illumination and re-discovered soft tissue originally noted and rarely cited.

Figure 1. Holotype of Scaphognathus GIF animation showing extent of wing membrane ignored by xx et al. 2018.

Figure 1. Holotype of Scaphognathus GIF animation showing extent of wing membrane ignored by xx et al. 2018.

Ironically
the authors ignored the most obvious aspect of the Scaphognathus soft tissue: the presence of a narrow chord wing membrane (Fig. 1), as documented by Peters (2002) and ignored ever since, per Chris Bennett’s threat, “You won’t get published, and if you do get published, you won’t get cited.”

Figure 2. Here is the Vienna specimen of Pterodactylus in situ and with matrix removed. Now compare this figure with figure 3, which shows the wings and uropatagia unfolding. There is no way to turn this into a deep chord wing membrane. And it decouples the forelimbs from the hind limbs.

Figure 2. Here is the Vienna specimen of Pterodactylus in situ and with matrix removed. Now compare this figure with figure 3, which shows the wings and uropatagia unfolding. There is no way to turn this into a deep chord wing membrane. And it decouples the forelimbs from the hind limbs.

The Vienna specimen of Pterodactylus
(Figs. 2, 3) are the prime examples of a narrow chord wing membrane, stretched between the wing tip and elbow… as in all pterosaurs that preserve soft tissue.

The Vienna Pterodactylus.

Figure 3. The Vienna Pterodactylus. Click to animate. Wing membranes in situ (when folded) then animated to extend them. There is no shrinkage here or in ANY pterosaur wing membrane. There is only an “explanation” to avoid dealing with the hard evidence here and elsewhere.

There are still no examples
of a deep chord wing membrane (attached to the ankle or tibia) preserved in any pterosaurs, as documented here, here, here and here.

References
Goldfuß A 1831. Beiträge zur Kenntnis verschiedener Reptilien der Vorwelt. Nova Acta Physico-Medica Academiae Caesareae Leopoldino-Carolinae Naturae Curiosorum, 15:61-128.
KRK Jäger, Tischlinger H, Oleschinski G, and Sander PM 2018. Goldfuß was right: Soft part preservation in the Late Jurassic pterosaur Scaphognathus crassirostris revealed by reflectance transformation imaging (RTI) and UV light and the auspicious beginnings of paleo-art. Palaeontologia Electronica 21.3.4T: 1-20. pdf
Peters D 2002. A new model for the evolution of the pterosaur wing – with a twist. Historical Biology 15: 277–301.

Is Jeholopterus pregnant? And what’s hiding in plain sight beneath that left wing?

There seems to be an overlooked egg shape
inside Jeholopterus, the vampire pterosaur, at just the right place (Figs. 1, 2; IVPP V12705). It’s not full term, so embryo/hatchling bones are not readily visible (= fully ossified) and currently impossible to reconstruct. Then again, that patch could be just a scuff mark.

Figure 1. Jeholopterus GIF animation showing new left wing shape plus underlying debris, perhaps in the form of theropod feathers.

Figure 1. Jeholopterus GIF animation showing new left wing shape plus underlying debris, some in the form of theropod feathers. Folded wings on pterosaurs should essentially disappear. This new interpretation follows that hypothesis. Click for an enlarged image.

Remember
pterosaurs are fenestrasaur – tritosaurlepidosaurs, so they are able to retain eggs within the mother’s body until just before hatching. Even their super-thin, lizard-like egg shells (or lack thereof) supports the present tree topology of pterosaurs as lepidosaurs in the large reptile tree (LRT, 1315 taxa) and disputes traditional models of archosaurian origin first invalidated by Peters 2000 by phylogenetic testing. Pterosaur eggs found alone (not near the mother) outside the body (like the IVPP anurognathid) include full term embryos. The Hamipterus egg accumulation chronicles a mass death of pregnant mothers, probably by lake burping.

Moreover
Jeholopterus seems to have landed on (= sunk on to after death) some theropod/bird feathers or similarly shaped pond plants. I suspected there was something wrong with that way-too-broad-while-folded wing. Pterosaur wings typically fold up to near nothingness, like bat wings do, when folded. It turns out, that’s the case here, too. There is a fringed trailing edge where the current and correct blue area ends. Make sure you click for a larger image.

Figure 2. Possible Jeholopterus premature egg in which embryo bones are not well calcified. Ribs and gastralia on a separate frame.

Figure 2. Possible Jeholopterus premature egg in which embryo bones are not well calcified. Ribs and gastralia on separate frames.

Look up at the left hand
of Jeholopterus and you’ll see there is some sort of fossilized matter (greenish color added on overlay) on the stratum that the specimen sank to. The same appears to be happening near the left wing tip, where something like feathers or long leaves appear, giving the illusion of a little too much pterosaur wing chord, especially in comparison to the right wing, which appears ‘normal.’

Figure 3. Jeholopterus counter plate in UV with brachiopatagium traced.

Figure 3. Jeholopterus counter plate in UV with brachiopatagium traced. UV image from Kellner et al. 2010.

Jeholopterus ninchengensis (Wang, Zhou, Zhang and Xu 2002) Middle to Late Jurassic, ~ 160 mya, [IVPP V 12705] was exquisitely preserved with wing membranes and pycnofibers on a complete and articulated skeleton (see below). Unfortunately the fragile and crushed skull was undecipherable to those who observed it first hand. Using methods described here, Peters (2003) deciphered the skull and identified the IVPP specimen of Jeholopterus as a vampire. In that hypothesis, Jeholopterus stabbed dinosaurs with its fangs, then drank their blood by squeezing the wound with its plier-like jaws while hanging on with its robust limbs and surgically sharp, curved and elongated claws. From head to toe, Jeholopterus stood apart morphologically. It was not your typical anurognathid. Derived from a sister to the CAGS specimen attributed to Jeholopterus, the holotype of Jeholopterus was a phylogenetic sister to Batrachognathus.

Figure 2. Reconstruction of Jeholopterus. This owl-like bloodslurper was covered with super soft pycnofibers to make it a silent flyer.

Figure 4. Reconstruction of Jeholopterus. This owl-like bloodslurper was covered with super soft pycnofibers to make it a silent flyer. Note the wider than tall torso and super long, super sharp claws.

These Jeholopterus wing images support
the narrow chord wing membrane stretched between elbow and wing tip (Peters 2002) and ignored by all subsequent workers. Note: Peters 2002 did not understand that something else made the left wing of Jeholopterus appear to have a deeper chord at mid wing. The illusion is that complete!

References
Cheng X, Wang X, Jiang S and Kellner AWA 2014. Short note on a non-pterodactyloid pterosaur from Upper Jurassic deposits of Inner Mongolia, China. Historical Biology (advance online publication) DOI:10.1080/08912963.2014.974038
Kellner AWA, Wang X, Tischlinger H, Campos DA, Hone DWE and Meng X 2010. The soft tissue of Jeholopterus (Pterosauria, Anurognathidae, Batrachognathinae) and the structure of the pterosaur wing membrane. Proc Royal Soc B 277: 321–329.
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.
Peters D 2002. A New Model for the Evolution of the Pterosaur Wing – with a twist. – Historical Biology 15: 277–301.
Peters D 2003. The Chinese vampire and other overlooked pterosaur ptreasures. Journal of Vertebrate Paleontology 23(3): 87A.
Wang X, Zhou Z, Zhang F and Xu X 2002. A nearly completely articulated rhamphorhynchoid pterosaur with exceptionally well-preserved wing membranes and “hairs” from Inner Mongolia, northeast China. Chinese Science Bulletin 47(3): 226-230.

wiki/Jeholopterus

New pterosaur hatchling video from Dr. Witton misinforms

A new video
from Dr. M. Witton looks at the possibility of gliding in hatchling pterosaurs. Unfortunately it is full of misinformation.

Distinct from what Dr. Witton is telling us,
pterosaur hatchling and juvenile proportions are not much different than their 8x larger adult forms. See link below and this growth series image: https://pterosaurheresies.wordpress.com/2015/12/15/pterodaustro-isometric-growth-series/

From the hatchling Pterodaustro image,
Dr. Witton has omitted the skull and neck, but it is present in the egg (it has to be!) and is nearly identical to that of the adult. We looked at a second embryo earlier here (Fig. 2), and for the first embryo see:  http://reptileevolution.com/pterodaustro-embryo.htm for details.
Figure 3. Rough reconstruction using color tracings. Note the elongate jaws and small eye, documenting isometric growth in this pterosaur, as in all others where this can be seen.

Figure 2. Rough reconstruction using color tracings. Note the elongate jaws and small eye, documenting isometric growth in this pterosaur, as in all others where this can be seen.

Relatively large hatchlings
were able to take flight shortly after hatching. True. The eggs were carried within the mother until ready to hatch, as in many lepidosaurs. The eggshell membrane is also lepidosaurian.
In direct contrast,
the fly-sized hatchllngs of tiny pterosaurs had to grow to a size at which they could leave their damp leaf litter environs, or suffer from desiccation based on their surface-to-volume ratio, as in the tiniest living lizards.  See: https://pterosaurheresies.wordpress.com/2011/08/11/the-tiniest-pterosaur-no-6/
Figure 4. Two of the smallest pterosaurs that both have a large sternal complex. BMNH42736 and B St 1967 I 276.

Figure 3. Two of the smallest pterosaurs that both have a large sternal complex. BMNH42736 and B St 1967 I 276.

Gliding is not an option
for baby pterosaurs hatching on the ground. Pterosaurs and their ancestors were flapping before they could fly. Gliding is an ability acquired later in large derived taxa, the same as in birds.
FIgure 8. Dimorphodon take off (with the new small tail).

FIgure 4. Dimorphodon take off (with the new small tail).

The quadrupedal launch
shown in several illustrations is not only bogus, but dangerous and inefficient for the pterosaur. Much better to use the giant flapping wing for thrust from the first moment of take-off. For details: https://pterosaurheresies.wordpress.com/2011/07/20/seven-problems-with-the-pterosaur-wing-launch-hypothesis/
Figure 8. A larger view of Nemicolopterus. Pedal digit 5 is relatively reduced here.

Figure 5. Nemicolopterus. This tiny taxon is close to Sinopterus, but closer to Shenzhoupterous. 

Dr. Witton discusses a Sinopterus dongi hatchling.
He is considering tiny adult Nemicolopterus (Fig. 5) a hatchling. The Nemicolopterus specimen has traits distinct from Sinopterus and nests separately in a cladogram closer to Shenzhoupterus, whereas all other adult/hatchling pairs nest together in a pterosaur cladogram. See: http://reptileevolution.com/nemicolopterus.htm
Figure 1. The new small Pteranodon wing, FHSM 17956, compared to Ptweety and the adult NMC41-358 specimen.

Figure 6. The new small Pteranodon wing, FHSM 17956, compared to Ptweety and the adult NMC41-358 specimen.

We know of not one, but two Pteranodon juveniles.
For details: http://reptileevolution.com/pteranodon-juvenile.htm
For all future and present paleontologists reading this blog.
It is vitally important that you back up your hypotheses with evidence. Don’t cherry-pick or cherry-delete data to fit your notions or fool an audience.

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.