A paper model of the ‘Discodactylus’ skull

Earlier a flat, but layered Adobe Photoshop plan of the skull of Discodactylus’ was presented (Fig. 1) and nested with the very similar anurognathid pterosaur, Vesperopterylus.

Figure 3. The skull of NJU-57003 reconstructed in animated layers for clarity. This is something the print media just cannot do as well. All elements are similar to those found earlier in other anurognathids.

Figure 1. The skull of NJU-57003 reconstructed in animated layers for clarity. This is something the print media just cannot do as well. All elements are similar to those found earlier in other anurognathids.

Here
a paper, paste and tape model of this plan is presented (Figs. 2, 3), made from a print out of the elements in figure 1.

Figure 1. Paper reconstruction of the Discodactylus skull and mandibles.

Figure 2. Paper reconstruction of the Discodactylus skull and mandibles. Yes, the dentary teeth don’t make sense. They are scattered in situ and this is not corrected here.

The extremely fragile skull
held together from below by slender palatal bones (maxillary palatal rods and hyoids not shown) provides a solution for a flying animal with a wide, rattlesnake-like gape.

Figure 3. Another view of the paper reconstruction of the skull and mandibles of Discodactylus.

Figure 3. Another view of the paper reconstruction of the skull and mandibles of Discodactylus.

Discodactylus megasterna (Yang et al. 2018; Middle-Late Jurassic; NJU-57003) is a complete skeleton of a disc-skull anurognathid with soft tissue related to Vesperopterylus (below). The sternal complex is quite large to match the wider than tall torso. Distinct from other anurognathids, m4.1 does not reach the elbow when folded.

This specimen was featured in a report (Yang et al. 2018) on pterosaur filaments that incorrectly aligned pterosaurs with feathered dinosaurs, rather than their true ancestors, the filamentous fenestrasaurs, Sharovipteryx and Longisquama.

Figure 4. Vesperopterylus skull reconstructed from color data traced in figure 3.

Figure 4. Vesperopterylus skull reconstructed 

Figure 2. Vesperopterylus reconstructed using original drawings which were originally traced from the photo. Manual digit 4.4 is buried beneath other bones and reemerges to give its length. Pedal digit 1 turns laterally due to metacarpal arcing and taphonomic crushing. There is nothing reversed about it. 

Figure 5. Vesperopterylus reconstructed using original drawings which were originally traced from the photo. Manual digit 4.4 is buried beneath other bones and reemerges to give its length. Pedal digit 1 turns laterally due to metacarpal arcing and taphonomic crushing. There is nothing reversed about it.

References
Yang et al. (8 co-authors) 2018. Pterosaur integumentary structures with complex feather-like branching. Nature ecology & evolution.

 

 

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Another disc-head anurognathid from Jurassic China

Yesterday Yang et al. 2018 presented NJU-57003 (Figs. 1–3), a small anurognathid pterosaur with a great deal of soft tissue preservation, including feather-like filaments, said to be homologous with feathers. That was shown to be invalid by taxon exclusion here.

Today we’ll reconstruct
the crushed skull using DGS and nest this specimen in a cladogram using phylogenetic analysis (Fig. 4) in a few hours. Yang et al. were unable or unwilling to do either, even with firsthand access to the fossil and nine co-authors.

Figure 1. The NJU-57003 specimen and outline drawing, both from Yang et al. 2018. Various membranes and the overlooked sternal complex are colored in here.

Figure 1. The NJU-57003 specimen and outline drawing, both from Yang et al. 2018. Various membranes and the overlooked sternal complex and prepubes are colored in here. Clearly the uropatagia are separated here, as in Sharovipteryx. No wing membrane attaches below the knee.

Overlooked by Yang et al.
the sternal complex is quite large beneath the wide-spread ribs, a trait common to anurognathids. The torso, like the skull, would have been much wider than deep in vivo.

Figure 2. The skull elements of NJU-57003 colored to help alleviate the chaos of the crushed specimen. See figure 3 for the same elements reconstructed.

Figure 2. The skull elements of NJU-57003 colored to help alleviate the chaos of the crushed specimen. I can’t imagine betting able to interpret this skull without segregating each piece with a different color. See figure 3 for the same elements reconstructed with these colors.

As in other disc/flathead anurognathids
the palatal processes of the maxilla (red in Figs. 2, 3) radiate across the light-weight palate.  Yang et al. mislabeled these struts the ‘palatine’ (Fig. 1) following in the error-filled footsteps of other pterosaur workers who did not put forth the effort to figure things out.

The skull
is likewise supported by relatively few and very narrow struts. Contra Yang et al. 2018, who once again, mistakenly identify the toothy maxilla as an scleral ring (Fig. 1), the actual scleral rings (Figs. 2, 3) are complete and smaller within a large squarish orbit bounded ventrally by a deep jugal.

Figure 3. The skull of NJU-57003 reconstructed in animated layers for clarity. This is something the print media just cannot do as well. All elements are similar to those found earlier in other anurognathids.

Figure 3. The skull of NJU-57003 reconstructed in animated layers for clarity. This is something the print media just cannot do as well. All elements are similar to those found earlier in other anurognathids. Note the eyes, as in ALL pterosaurs, are in the back half of the skull.

Discodactylus megasterna (Yang et al. 2018; Middle-Late Jurassic, Yanlio biota, 165-160mya; NJU-57003) is a complete skeleton of a disc-skull anurognathid with soft tissue related to Vesperopterylus. The sternal complex is quite large to match the wider than tall torso. Distinct from other anurognathids, m4.1 does not reach the elbow when folded.

Figure 4. Subset of the LPT nesting Discodactylus with Vesperopterylus within the Anurognathidae.

Figure 4. Subset of the LPT nesting Discodactylus with Vesperopterylus within the Anurognathidae.

This specimen was introduced without a name
in a paper that incorrectly linked pterosaur filaments to dinosaur feathers (Yang et al. 2018), rather than with their true ancestor/relatives, the filamentous fenestrasaurs, Sharovipteryx and Longisquama, taxa omitted in Yang et al. and all workers listed below. Details here. The authors were unable to score traits for the skull and did not mention Vesperopterylus in their text.

Apparently the same artist
who originally traced the skull of Jeholopterus in 2003 (Fig. 5) also traced the present specimen (Fig. 1) with the same level of disinterest and inaccuracy. Compare the original image (Fig. 5 left) to a DGS image (Fig. 5 right). 

Figure 5. The original 2003 tracing of Jeholopterus (upper left) was inaccurate, uninformed and uninformative despite first hand access compared to the more informative and informed tracing created using DGS methods.

Why did these anurognathids have such long filaments?
Owls use similar fluffy feathers to silence their passage through air, first discussed earlier here.

The pterosaur experts weigh in the-scientist.com/news:
“I would challenge nearly all their interpretations of the structures. They are not hairs at all, but structural fibers found inside the wings of pterosaurs, also known aktinofibrils,” says pterosaur researcher David Unwin at the University of Leicester in the UK who was not part of the study. “They discovered lots of hair-like structures, but [don’t report any] wing fibers. I find that problematic.” Unwin suspects these fibers are likely to be present but have been mislabeled as feathers.  

This is a very important discovery,” says Kevin Padian, a palaeontologist at the University of California, Berkeley, “because it shows that integumentary [skin] filaments evolved in both dinosaurs and pterosaurs. That’s not surprising because they are sister groups, but it is good to know.”  

Padian draws attention to the pycnofibers’ “hair-like structure” as illustrating that they served as insulation. This is yet another characteristic of dinosaur and pterosaurs, along with high growth rate, pointing to their common ancestor as warm blooded.  “I wish the illustrations in the paper were better, but there is no reason to doubt them,” he adds.

Dr. Padian knows better.
He’s keeping the family secret by not mentioning fenestrasaurs (Peters 2000).

“The thing that is cool is that it bolsters the idea that pterosaurs and dinosaurs are sister taxa, if they are correct in interpreting these structures as a type of feather,” writes paleobiologist David Martill of the University of Plymouth in the UK, in an email. 

Dr. Martill knows better.
He’s keeping the family secret by not mentioning fenestrasaurs.

The specimens described in the paper are very interesting, agrees Chris Bennett, a palaeontologist at Fort Hays State University in Kansas, but in an emailed comment he describes the interpretation of the structures as problematic. “The authors’ characterization of the integumentary structures as ‘feather-like’ is inappropriate and unfortunate,” he writes. Some of the structures look like they could be from fraying or other decomposition, rather than feathers. Bennett adds that filamentous structures for insulation and sensation are fairly common, from hairy spiders to caterpillars to furry moths. “It seems to me to be premature to use filamentous integumentary structures to support a close phylogenetic relationship between pterosaurs and dinosaurs,” says Bennett. 

Dr. Bennett knows better.
He’s keeping the family secret by not mentioning fenestrasaurs.

Benton stands by his conclusion that pterosaurs wore plumage. Asked about the suggestion that the feathers could be wing fibers, he writes in an email, “Actinofibrils occur only in the wing membranes, whereas the structures we describe occur sparsely on the wings, but primarily over the rest of the body.”

Dr. Benton knows better.
He’s keeping the family secret by not mentioning fenestrasaurs. More details here.

References
Bennett SC 1996. The phylogenetic position of the Pterosauria within the Archosauromorpha. Zoological Journal of the Linnean Society 118:261-308.
Hone DWE and Benton MJ 2007.
An evaluation of the phylogenetic relationships of the pterosaurs to the archosauromorph reptiles. Journal of Systematic Palaeontology 5:465–469.
Hone DWE and Benton MJ 2009.
Contrasting supertree and total evidence methods: the origin of the pterosaurs. Zitteliana B28:35–60.
Peters D 2000. 
A Redescription of Four Prolacertiform Genera and Implications for Pterosaur Phylogenesis. Rivista Italiana di Paleontologia e Stratigrafia 106 (3): 293–336.
Yang et al. (8 co-authors) 2018. Pterosaur integumentary structures with complex feather-like branching. Nature ecology & evolution doi:10.1038/s41559-018-0728-7

 

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

SVP 2018: Resolving the Mesadactylus complex of individual bones

Figure 1. Mesadactylus restored from available data as an anurognathid.

Figure 1. Mesadactylus restored from available data as an anurognathid.

The BYU specimens attributed to 
Mesadactylus 
nest with anurognathids like ?Dimorphodon weintraubi (coeval and also from North America) in the large pterosaur tree (LPT). The specimen is Late Jurassic (Morrison Formation) in age.

Sprague and McLain 2018 conclude, “the taxonomic affinity of the genus is uncertain.” So why did they title their talk “Resolving…”

All they had to do
was Google “Mesadactylus.” Or run a phylogenetic analysis. The affinities of this specimen have been known here at the LPT since 2012.

References
Spratue M and McLain MA 2018. Resolving the Mesadactylus complex of Dry Mesa Quarry, Morrison Formation, Colorado. SVP Abstracts.

Flugsaurier 2018: Anurognathid JPM 2012-001

Flugsaurier 2018 part 3
Since the purpose of the symposium is increase understanding of pterosaurs, I hope this small contribution helps.

Lü et al. 2018 report on two new and unnamed anurognathid pterosaurs
from China. I’m guessing the one featured today has been known for six years based on its number: JPM-2012-001.

FIgure 1. The JPM 2012-001 anurognathid in situ. DGS overlay makes bones easier to delineate, identify and use in a reconstruction, figure 2. Look at those tiny toes! At 72 dpi screen resolution, this is just slightly larger than life size. The fourth wing phalanx is disarticulated.

FIgure 1. The JPM 2012-001 anurognathid in situ. DGS overlay makes bones easier to delineate, identify and use in a reconstruction, figure 2. Look at those tiny toes! At 72 dpi screen resolution, this is just slightly larger than life size. The fourth wing phalanx is disarticulated.

According to Lü et al. 2018
“Based on body morphologies, anurognathid pterosaurs can be classified into two subgroups: long-tailed anurognathids (length ratio of tail to femur is greater or equal to 1) and short-tailed anurognathids (length ratio of tail to femur is smaller than 1).” The JPM specimen is a long-tailed type.

Figure 2. Reconstruction of JPM-2012-001, this anurognathid has a rather tall skull. Crushing makes the elements difficult to identify, which is where DGS excels. M4.4 is disarticulated in situ. Note in situ the skull is bent back 180º. Shown slightly smaller than life size.

Figure 2. Reconstruction of JPM-2012-001, this anurognathid has a rather tall skull. Crushing makes the elements difficult to identify, which is where DGS excels. M4.4 is disarticulated in situ. Note in situ the skull is bent back 180º. Shown slightly smaller than life size.

The second Chinese anurognathid, BPMC-0009,
is not shown in its entirety in Lü et al. 2018. Rather the authors focus on the tiny fourth phalanx at the wing tip (which also includes an ungual!). Lü et al. 2018 report, “The extremely reduced wing phalange 4 (its length is 4.6mm) may indicate that the so-called three wing-phalanged pterosaurs: Anurognathus (Bennett, 2007) and Beipiaopterus (Lü, 2003) may be caused by extremely reduced wing phalanx 4 and this phalanges did not preserve, and the expanded distal end of the wing phalanx 3 perhaps confirm this possibility (this distal of wing phalanx 4 is sharp and pointed).”

Figure 3. The holotype German Anurognathus to scale with the Chinese anurognathid JPM-2012-001, based on the naming policies of Rhamphorhynchus, Pteranodon and other pterosaurs, these two are congeneric.

Figure 3. The holotype German Anurognathus to scale with the more gracile Chinese anurognathid JPM-2012-001, Based on the naming policies of Rhamphorhynchus, Pteranodon and other pterosaurs, these two are congeneric, despite their many differences.

Unfortunately,
the basal azhdarchid, Beipiaopterus, has four wing phalanges. So does the flathead anurognathid SMNS 81928(not congeneric with the holotype Anurognathus), which also has four wing phalanges. See them in situ here and here. All anurognathids have four wing phalanges. Regarding BPMC-0009Jeholopterus also has a relatively small m4.4, so it may be related to the BPMC-0009 specimen. We’ll have to see the complete specimen to make that determination.

Not listed by the authors,
the UNSM 93000 specimen of Nyctosaurus does have only three wing phalanges, discussed earlier here.

The JPM specimen
has a long tail —but it nests with the short tailed Anurognathus (holotype, Fig. 3). So there goes the earlier Lü et al. hypothesis about splitting anurognathids. Under the Lü et al. hypothesis, you will have to know that every tiny caudal bone was on the matrix surface, preserved and able to be seen. Think how easy it would be for such tiny, pollen-sized, distal caudals to be buried… or lost during taphonomy. Besides, no one wants to pull a Larry Martin, splitting or lumping taxa based on one  trait. Use all 180+ traits in the large pterosaur tree (LPT). And make reconstructions to test your observations!

Figure 1. Clck to enlarge and animate. Here the buried wing phalanges are shown along with more tail vertebrae and wing membranes. Boosting the contrast brings some close-to-the-surface parts to more prominence.

Figure 4. Clck to enlarge and animate. Here the buried wing phalanges are shown along with more tail vertebrae and wing membranes. Boosting the contrast brings some close-to-the-surface parts to more prominence.

Anurognathids have a long history
of bad reconstruction. So does Anurognathus. Note, as in Vesperopterylus and all other anurognathids (Fig. 5), there is no trace of a giant scleral ring in the anterior half of the JPM specimen skull (Figs. 1–3, contra Bennett 2007 and the current fashion among pterosaur workers and artists). Rather, and just like related Dimorphodon, the antorbital fenestra is quite large and the orbit is right behind it.

Figure 1. Anurognathid skulls in phylogenetic order.

Figure 5. Anurognathid skulls in phylogenetic order. None have a giant sclerotic ring in the anterior of the skull. Rather, all have a large antorbital fenestra.

Like the holotype Anurognathus,
(Fig. 3) the JPM-2012-0001 specimen has longer dentary teeth (deeper than the mandible), an antorbital fenestra taller than the orbit (convergent with azhdarchids and tapejarids), a tiny metacarpus and a long list of other shared traits. The JPM specimen is more gracile overall, with smaller feet, more slender wing finger, a larger sternal complex and a shorter, taller skull.

References
Bennett SC 2007. A second specimen of the pterosaur Anurognathus ammoni. Paläontologische Zeitschrift 81(4):376-398.
Lü J-C, Zhou X-Y, Liu C-Y and Sun D-Y 2018.
Chinese anurognathid pterosaurs. Flugsaurier 2018: the 6th International Symposium on Pterosaurs. Los Angeles, USA. Abstracts:63-65.

https://pterosaurheresies.wordpress.com/2014/02/13/anurognathid-eyes-the-evidence-for-a-small-sclerotic-ring/

Giant flying arboreal mammal-killer in the Jehol (Early Cretaceous, China)

So… this one has been under the radar since 2004
And you’ll see why.

Like a prehistoric eagle,
this was the largest flying predator in the Jehol biota (Early Cretaceous, China). It had no feathers. And it has gone unrecognized as a giant flying predator since Wang and Zhou 2004 announced it in Nature for other reasons.

At this time the only evidence
for this taxon comes in the form of a giant embryo anurognathid pterosaur, IVPP V13758 (Fig. 1) the size of other adult anurognathids. As an adult it would have been 8x larger (if similar to other pterosaur and based on the pelvic opening). The skull retains traits of the related, but more basal Dimorphodon from the Early Jurassic of England, but the giant anurognathid was coeval and similar in size to another Jehol predator, the pre-tyrannosauroid, Tianyuraptor, and larger than a coeval four-winged, flight-feathered ornitholestid, Microraptor (Fig. 1). It was also larger than the modern bald eagle (Haliaeetus leucocephalus). All the early Cretaceous toothed birds, like Yanornis, and Hongshanornis, were smaller.

Figure 1. Adult scaled version of the IVPP anurognathid pterosaur, with a skull similar in size to those attributed to Dimorphdodon. Bergamodactylus and Preondactylus are ancestral to Dimorphodon. Other Jehol predators are shown in white.

Figure 1. Adult scaled version of the IVPP anurognathid pterosaur, with a skull similar in size to those attributed to Dimorphdodon. Bergamodactylus and Preondactylus are ancestral to Dimorphodon. Other Jehol predators are shown in white.

If early Cretaceous mammals thought they were safe up in the trees,
think again. This giant anurognathid kept their numbers in check by going after them in the trees. That’s a big guess, but if you’re looking for a predator capable of snatching mammals out of the trees, there are no other candidates in the Early Cretaceous of China. Just look at those teeth!

Most anurognathids were small
because they ate small insect prey. Ask yourself if something as large as the IVPP embryo as an adult would have been satisfied eating insects. No, it was going after larger prey.

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 2. 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.

Unfortunately
Wang and Zhou 2004 (Fig. 3) didn’t know what sort of pterosaur their first embryo/egg was. Back then they thought pterosaur babies had a shorter rostrum that adults. Wrong. Back then they thought anurognathids were all small taxa. Wrong. Back then they didn’t spend much time tracing traits (Fig. 3) and reconstructions were largely guesswork. We fix all those problems here and at ReptileEvolution.com

The IVPP embryo pterosaur

Figure 3. Click to enlarge DGS tracing. The IVPP embryo pterosaur (far left) as originally traced, (near left) as originally reconstructed as a baby ornithocheirid, (near right) traced using the DGS method, (far right) adult reconstructed at 8x the embryo size.

We first looked at the IVPP embryo
here, several years ago and several times since.

Figure 4. The IVPP embryo anurognathid compared to other basal pterosaurs.

Figure 4. The IVPP embryo anurognathid enlarged to adult size and compared to other basal pterosaurs.

References
Wang X-L and Zhou Z 2004. Palaeontology: pterosaur embryo from the Early Cretaceous. Nature 429: 623.

http://reptileevolution.com/dimorphodon.htm
http://reptileevolution.com/ivpp-embryo.htm

https://pterosaurheresies.wordpress.com/2011/07/26/what-do-those-pterosaur-embryos-really-look-like/

Vesperopterylus (aka: Versperopterylus, Lü et al. 2017) did not have a reversed first toe

And this specimen PROVES again
that anurognathids DID NOT have giant eyeballs in the anterior skull.

Figure 1. Vesperopterylus in situ. There is nothing distinct about pedal digit 1.

Figure 1. Vesperopterylus in situ. There is nothing distinct about pedal digit 1.

Lü et al. 2017 bring us a new little wide-skull anurognathid
Vesperopterylus lamadongensis (Lü et al. 2017) is a complete skeleton of a wide-skull anurognathid. It was considered the first pterosaur with a reversed first toe based on the fact that in digit 1 the palmar surface of the ungual is oriented lateral while digis 2–4 the palmar surfaces of the unguals are medial. That is based on the slight transverse curve of the metatarsus (Peters 2000) and the crushing which always lays unguals on their side. In life the palmar surfaces were all ventral and digit 1 radiated anteriorly along with the others.

Figure 2. Vesperopterylus reconstructed using original drawings which were originally traced from the photo. Manual digit 4.4 is buried beneath other bones and reemerges to give its length. Pedal digit 1 turns laterally due to metacarpal arcing and taphonomic crushing. There is nothing reversed about it. 

Figure 2. Vesperopterylus reconstructed using original drawings which were originally traced from the photo. Manual digit 4.4 is buried beneath other bones and reemerges to give its length. Pedal digit 1 turns laterally due to metacarpal arcing and taphonomic crushing. There is nothing reversed about it.

Lü et al were unable to segregate the skull bones.
Those are segregated by color here using DGS (Digital Graphic Segregation). See below. Some soft tissue is preserved on the wing. Note: I did not see the fossil first hand, yet I was able to discern the skull bones that evidently baffled those who had this specimen under a binocular microscope. Perhaps they were looking for the giant sclerotic rings in the anterior skull that are not present. Little ones, yes. Big ones, no.

Figure 1. Vesperopterylus skull with bones identified by DGS (digital graphic segregation). Lü et al. were not able to discern these bones and so left the area blank in their tracing. Note the complete lack of a giant eyeball in the front of the skull. Radius and ulna were removed for clarity and to show a complete lack of giant eyeballs (sclerotic rings) in the anterior skull. 

Figure 1. Vesperopterylus skull with bones identified by DGS (digital graphic segregation). Lü et al. were not able to discern these bones and so left the area blank in their tracing. Note the complete lack of a giant eyeball in the front of the skull. Radius and ulna were removed for clarity and to show a complete lack of giant eyeballs (sclerotic rings) in the anterior skull.

This skull reconstruction
(Fig. 4) is typical of every other anurognathid, because guesswork has been minimized here. After doing this several times with other anurognathids, I knew what to look for and found it. No giant sclerotic rings were seen in this specimen.

Figure 4. Vesperopterylus skull reconstructed from color data traced in figure 3.

Figure 4. Vesperopterylus skull reconstructed from color data traced in figure 3. Due to the angled sides of the skull some foreshortening was employed  to match those angles. Original sizes are also shown.

With regard to perching
all basal pterosaurs could perch on branches of a wide variety of diameters by flexing digit 1–4 while extending digit 5, acting like a universal wrench (Peters 2000, FIg. 5). This ability has been overlooked by other workers for the last two decades,

Figure 1. The pterosaur Dorygnathus perching on a branch. Above the pes of Dorygnathus demonstrating the use of pedal digit 5 as a universal wrench (left), extending while the other four toes flexed around a branch of any diameter and (right) flexing with the other four toes. As in birds, perching requires bipedal balancing because the medially directed fingers have nothing to grasp.

Figure 1. The pterosaur Dorygnathus perching on a branch. Above the pes of Dorygnathus demonstrating the use of pedal digit 5 as a universal wrench (left), extending while the other four toes flexed around a branch of any diameter and (right) flexing with the other four toes. As in birds, perching requires bipedal balancing because the medially directed fingers have nothing to grasp.

I have not yet added Vesperopterylus
with the holotype of Anurognathus in the large pterosaur tree.

References
Lü J-C et al. 2017. Short note on a new anurognathid pterosaur with evidence of perching behaviour from Jianchang of Liaoning Province, China. From: Hone, D. W. E., Witton MP and Martill DM(eds) New Perspectives on Pterosaur Palaeobiology.
Geological Society, London, Special Publications, 455, https://doi.org/10.1144/SP455.16
Peters D 2000. Description and Interpretation of Interphalangeal Lines in Tetrapods. 
Ichnos, 7: 11-41