What is a flamingo in the cladogram of birds?

In the present subset
of the large reptile tree (LRT, 1090 taxa, Fig. 3) flamingoes (genus: Phoenicopterus, Fig. 1) nest with the seriema (genus: Cariama, Fig. 2). That makes the flamingo a sort of bird of prey, now concentrating on tiny plankton (algae + invertebrates). That’s why they are so distinct.

Wikipedia lists several studies
that nest flamingoes with ducks, spoonbills and/or doves.

Prum et al. 2015 used DNA
to nest flamingoes with grebes. These submersible sharp-rostrum, hind limb swimmers have not yet been added to the LRT, but grebes look more like loons, similar to Gavia. Until that analysis,  here’s a loon skeleton online. So when grebes are added, I’ll let you know how that works out.

The closest tested relative
of Phoenicopterus in the Prum et al. tree is Uria, the murre, which we looked at yesterday, Here, Uria nests between dippers and penguins, far from Phoenicopterus (Fig. 3).

So, apparently there is no consensus
out there regarding flamingo relatives. Are the flamingo-like traits of Cariama convergent or homologous? The answer has to come from comparative anatomy. DNA fails too often to deliver sisters who actually look like one could evolved from the other or from a common ancestor sharing a long list of traits.

Figure 1. Phoenicopterus, the flamingo, currently and provisionally nests with Cariama in the LRT.

Phoenicopterus chilensis (Molina 1782) is the extant flamingo, a long-legged filter-feeder with pink plumage. Here it ness with Cariama, the seriema.

Figure 2. The seriema (genus: Cariama) is the closest taxa to Yanornis in the LRT. The two resemble one another in most details, but Cariama lacks teeth, has a retracted naris and an elevated pedal digit 1.

Cariama cristatus (Linneaus 1766) is the extant seriema, a grasslands predator from South America. It flies only to escapte predators. Here it is basal to the flamingo, Phoenicopterus. At present it is easy to see why they nest together. And this is where the LRT shines.

Figure 1. Subset of the LRT focusing on birds. Here various aspects of birds are shown, including age, teeth, feeding behavior and basic clades.

If anyone can find a better match
for flamingoes, please let me know. Otherwise, you heard it here first. Meanwhile, I’m surprised to see what I learn in just a few hours has not been discovered before. This is not rocket science.

References
Linneaus C 1766. Systema naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Tomus I. Editio duodecima, reformata. Holmiae. (Laurentii Salvii).: 1-532.
Molina JI 1782. Saggio sulla Storia Naturale del Chili. Bologna, Stamperia di S. Tommaso d’Aquino. 349 pp.

wiki/Flamingo
wiki/Seriema

 

Murres and the origin of penguins

Updated January 8, 2018
with the deletion of dippers, which now nest with wrens when more taxa are added.

Updated August 11, 2021
with the revelation that the skeleton tested in 2017 was Uria aalge, mislabeled Uria lomvia below. The in vivo Uria in figure 2 is also Uria lomvia (Fig. 1).  The former still nests with penguins. The latter now nests with auks. See figure 1.

Today
we’re going to take a heretical look at the origin of penguins, those short-legged, super-insulated, flightless, fish- & squid-eaters. Some can dive for 22 minutes down to 550 meters.

According to Wikipedia
the relationships of the penguin subfamilies (order: Sphenisciformes) and the placement of penguins among the birds “is not resolved.” By contrast, in the LRT the relationship of penguins among birds is completely resolved.

Basal penguins,
like Waimanu, are known from Antarctica and New Zealand from the early Paleocene. Waimanu was flightless and likely swam with both its short wings and paddling feet. This derived bird at the K-T boundary points to a much earlier radiation of more primitive, crane-like extant birds, apparently starting just before Yanornis in the Early Cretaceous.

In the large reptile tree
(LRT, 1089 taxa, now 1898+ taxa) penguin ancestors going back to Devonian fish are recovered. However, presently and provisionally two taxa are proximal penguin sisters in the LRT and these are derived from even more basal and high-energy grebes and kingfishers.

FIgure 2. Uria aalge and Aptenodytes, two taxa in the origin of penguins. Despite their apparent differences, the LRT nests these three taxa together in a single clade.

Representing a transitional phase
Murres like Uria (Fig. 2; 45cm), traditional nest with snipes, plovers, terns, stilts, gulls puffins and auks (= Charadriiformes),. That’s a pretty diverse clade. Some of these also appear in the penguin clade of the LRT. Many workers consider murres to be unrelated to penguins, despite appearances. Murres are all north of the equator, while penguins stay south. Uria has pelican-like plumage (black and white) and is better adapted to swimming underwater (up to  4 minutes) with a longer torso and longer sternum. Digit 1 becomes a vestige and the rib cage extends nearly to the ankle. Murres live in colonies near sea waters.

Penguins like Aptenodytes (Fig. 3) traditionally nest with loons, like Gavia. Here (Fig. 1) they don’t. Penguins are flightless, trend toward larger, can swim better and seek larger prey. Finger 1 disappears. The pygostyle straightens out. The scapula grows larger. The metatarsus becomes shorter than the pedal digits. Again, these are all minor and gradual accumulations of traits.

Uria lomvia (Linneaus 1758; 45cm tall) is the extant thick-billed murre. It is a strong flyer, both in the air and underwater. Here it is basal to auks.

References
Deguine, J-C 1974. Emperor Penguin: Bird of the Antarctic. The Stephen Greene Press, Vermont.
Hackett S et al. 2008. A phylogenetic study of birds reveals their evolutionary history. Science 320:1763–1768.
Linnaeus C 1758. Systema naturæ per regna tria naturæ, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Tomus I. Editio decima, reformata.

wiki/Penguin
wiki/Uria

African hamerkop, Antarctic petrel and American vulture

These three extant bird taxa nest together [Not anymore they don’t]
in the large reptile tree (LRT, 1089 taxa then 2024 taxa now) and it’s easy to see why when you look at their skulls (Figs. 1–3). On the inside they are more like each other than any other tested taxa. We usually see them from the outside (Figs. 4–6).

Updated December 24, 2021
with almost 950 more taxa (Fig. 9) and several bouts of housekeeping. Vultures nest with hawks. Hamerkops nest with hornbills. Petrels are now separated from hamerkops by ducks + geese.

Figure 1. Scopus umbretta, the extant African hamerkop.

Scopus umbretta (Brisson 1760, 56 cm tall) is the extant hamerkop, a mid-sized wading bird (Figs, 1, 4). In the LRT it nests with the petrel, Macronectes, Note: the maxilla is much longer in these taxa.

Figure 3. Macronectes giganteus, the extant Southern giant petrel.

Macronectes giganteus (Gmelin 1789; 56 cm tall) is the extant Southern giant petrel, a member of the Procellariidae and Procellariformes (tubenoses). Here it nests with Scopus and Pelagornis . This soaring sea bird has a wingspan up to 2m. Note the naris has shifted anteriorly along with the maxilla.

Figure 3. Coragyps atratus, the extant black vulture.

Coragyps atratus (LaMout 1853; 56 cm in length, 1.5m wingspread) is the extant black vulture and a sister to the giant petrel. Note the similar premaxilla. As in Threskiornis(below), the head and neck lack feathers.

Figure 4. Scopus, the hamerkop, in vivo.

One of the current problems in bird phylogeny
is how to tie the various orders of birds together at their roots. Which orders are related to which other orders? Here’s how the situation stands according to Wikipedea:

1. Hamerkop family: Scopidae, order: Pelecaniformes
2. Petrel family: Procellariidae, order: Procellariformes
3. Vulture family: Cathartidae: order: Accipitriformes

According to Wiki:
Pelecaniformes include the pelican, shoebills, hamerkops, ibises, spoonbills, herons, egrets and bitterns. In the LRT, SOME of these disparate taxa nest at disparate nodes. Others have not been tested yet.

Frigate birds, gannets and boobies, cormorants, darters and tropic birds used to be in this clade, but DNA and morphological studies indicate otherwise. “Recent research strongly suggests that the similarities between the Pelecaniformes as traditionally defined are the result of convergent evolution rather than common descent.” None of these have been tested yet. Most have a bare throat patch (gular patch), and the nostrils have evolved into dysfunctional slits, forcing them to breathe through their mouths.

Figure 5. Macronectes, the Southern giant petrel, in vivo.

According to Wiki
Procellariiformes include the petrel and albatross. These, in turn, are most closely related to penguins and loons. The LRT (Fig. 7) finds several taxa nest between penguins and loons, including dippers, kingfishers and hummingbirds, but we’ll save that for another day.

Figure 6. Coragyps, the black vulture, in vivo.

According to Wiki:
Accipitriformes include the New World vultures, the hawk, secretary bird and eagle, but not the falcon and owl. DNA nests falcons closer to parrots and sparrows. Accipitriformes are carnivorous with raptorial claws and a sharply hooked beak, but the same can be said of falcons and parrots. Here (Fig. 7) falcons, like Falco, nest with the terror birds and their extant relatives, not with parrots.

Well, this is embarrassing!
Yesterday’s post had roadrunners linked to herons. Everyone knows roadrunners are a type of cuckoo. Today, with the addition of Coccyzus, the cuckoo, that problem resolves itself. The LRT nests both cuckoos with the heron, Ardea (Fig. 7). This series appears to  document another example of serial phylogenetic miniaturization, with a smaller and smaller overall size coupled with shorter legs (neotony) and a return to the down curved rostrum found in the ratite ancestors of herons, like Rhynchotus.

Figure 8. Members of the cuckoo/heron clade along with a baby heron.

As We’ve seen before
DNA results do not match morphological results over larger phylogenetic distances. And the same appears to hold true for extant birds. I thought the birders had this all figured out, but apparently there is room for yet another hypothesis of relationships here. The LRT bird tree topology is, so far, staying pretty simple and logical.

Figure 9. Bird cladogram from 12/24/2021 with 950 more taxa in the LRT. Follow this latest data.

Nullius in verba

References
Brisson MJ 1760. Ornithologie, ou, Méthode contenant la division des oiseaux en ordres, sections, genres, especes & leurs variétés : a laquelle on a joint une description exacte de chaque espece, avec les citations des auteurs qui en ont traité, les noms quils leur ont donnés, ceux que leur ont donnés les différentes nations, & les noms vulgaires
Gmelin JF 1789. Caroli a Linné … Systema Naturae per Regna Tria Naturae, Secundum Classes, Ordines, Genera, Species, Cum Characteribus, Differentiis, Synonymis, Locis. Editio Decima Tertia, Aucta, Reformata/ cura Jo. Frid. Gmelin. Volume 1, part 3. Lipsiae: Impensis Georg. Emanuel. Beer.
Latham J 1790.  Index Ornithologicus, Sive Systema Ornithologiae: Complectens Avium Divisionem In Classes, Ordines, Genera, Species, Ipsarumque Varietates (2 Volumes) (in Latin). London: Leigh & Sotheby.
LeMaout 1853. xx

wiki/Scopus
wiki/Threskiornis
wiki/Macronectes
wiki/Coragyps atratus

Roadrunner skull and surface features

These two images of the extant roadrunner
(Fig. 1; genus: Geococcyx) were so close to each other, they presented a great opportunity to match skull to surface features on one of our favorite birds.

Figure 1. GIF animation of Geococcyx skull matched to surface feathers. Distinct from other birds tested so far, the nares is far forward, apart from the antorbital fenestra.

A minimum of guesswork
and/or imagination was used in the creation of this image. Since the skull is a cast, sutures were ‘sutured’ to create a single object.

Geococcyx californum 
(Wagler 1831; up to 60 cm longl) the extant roadrunner is a small terrestrial heron and a basal neognath with a posteriorly rotated pedal digit 4, unrelated to parrots and toucans with a similar toe. Traditionally roadrunners are considrered part of the cuckoo family. When cuckoos get tested, they may also nest here. They have shorter hind legs.

Figure 2. Geococcyx the roadrunner skeleton. Note the crane-like proportions of this small land heron, probably a late-surviving Early Cretaceous member of the Euornithes.

And where does the roadrunner nest
in the large reptile tree (LRT 1087 taxa)? Between toothy Yanornis and toothless Ardea, the heron, all three at the base of the neognath birds, not surprisingly close to Sagittarius and Cariama, two other extant bird terrestrial predators with long hind limbs.

Nullius in verba

References
Wagner JG 1831. Einige Mitheilungen über Thiere Mexicos. Oken’s Isis 24:510–535.

wiki/Roadrunner

Extant bird phylogeny: basal divisions

Using the same 231 characters from
the large reptile tree (LRT, 1085 taxa) the subset of extant birds and their allies also came out fully resolved (Fig. 1).

Figure 1. 5-frame GIF of a subset of the LRT focused on extant birds and their closest relatives. Though incomplete, patterns are emerging. Please note: Aepyornis now nests with Struthio. 

Prum et al. 2015 used DNA
to determine the phylogeny of Neoaves (nearly all living bird species). They reported this “remains the greatest unresolved challenge in dinosaur systematics”, but that was before the recent alignment of Ornithischia and Theropoda by Baron et al. 2017.

I have to admit
as usual, before I started adding more extant birds to the LRT, I knew nothing about them. Their generic names were new to me. You might remember the LRT started with just a chicken (Gallus) and an ostrich (Struthio). Now there are 42 birds with 143 outgroup taxa.

Birds are tough.
Often they fuse skull bones. That may be why other workers find protrusions and bumps to base their traits on. Some of the best data for many taxa come from decades old drawings and photos from skull sellers. I made many mistakes along the way, now minimized. The cladogram was my mentor here, telling me with autapomorphies where to look for mistakes.

Matching all prior workers,
tinamous and ratites were recovered as basalmost taxa. In the Prum et al. DNA study, chickens, crakes, screamers and ducks branch off first. In the LRT, which includes extinct taxa, the predators and toothed birds split off first. Distinct from the Prum et al. study, in the LRT long-legged walking birds are basal to many clades. Even the basalmost toothed bird, Yanornis, from the Early Cretaceous, is a long-legged walking bird, also capable of flying. And yes, this puts the origin of the clade of extant birds back to just after the Jurassic. Jurapteryx, from the Late Jurassic, is not far off.

Herons come next,
followed by all other birds with the corn crake (Crex) the hammerkop (Scopus) and the limp kin (Aramus) at the base. Adding taxa allows me to amend an earlier nesting of the elephant bird (Aepyornis) with ducks. Now Struthio and Aepyornis nest together.

In the Prum et al. study
swifts + hummingbirds split off after chickens + ducks.

By contrast,
in the LRT swifts (Eocypselus) and hummingbirds (Archilochus) nest between terns (Thalasseus) and kingfishers (Megaceryle). Nearby, high-energy dippers (Cinclus) nest with other wing swimming birds: murres (Uria) and penguins (Aptenodytes). Cinclus is traditionally considered a passerine, but the sparrow, Passer, does not nest with it in the LRT. Passer nests between chickens and parrots (Ara), all seed eaters.

In the Prum et al. study
seed-eating passerines arise from carnivorous falcons and seriema (Cariama). That does not seem right on the face of it. In the LRT passerines arise from omnivores, like Chauna.

Neotony
juvenile traits found in adult specimens, evidently produced all of our short-legged birds and produced smaller adult birds, found at derived nodes. Juveniles of flamingos and other long-legged taxa have short legs. Of course, some small birds also had large and giant descendants, all at derived nodes.

As in many studies that conflict with the LRT
the lack of appropriate fossil outgroup taxa seems to set their cladograms in other directions. That can happen. DNA studies can never solve this problem.

Apologies for earlier mistakes due to
naive misidentifications and taxon exclusion. Those will be repaired.

Nullius in verba

References
Baron MG, Norman DB, Barrett PM 2017. A new hypothesis of dinosaur relationships and early dinosaur evolution. Nature  543:501–506.
Prum RO et al. (6 coauthors) 2015. A comprehensive phylogeny of birds (Aves) using targeted next-generation DNA sequencing.

Intriguing little raptorial foot on a living bird

Figure 1. Foot of the extant seriema (genus Cariama) with digit 2 elevating the sharp and highly curved killing claw.

The extant seriema
(Cariama cristatus) has an elevated pedal digit 2 killer claw, just like that of its Mesozoic distant relatives, Velociraptor and Deinonychus. This is yet one more example of ancient genes expressing themselves once again after traits have been lost in birds.

Figure 2. The seriema (genus: Cariama) is a long-legged high-grass predator with a raptor-like foot. 

At the Paleognath/Neognath transition is Yanornis.

A quick note today best told in images
Back at the studio I’m still busy trying to unravel basal neognath birds (extant birds sans the kiwi, ostrich, tinamou and their allies). Details are popping out, like this one today.

Figure 1. Yanornis (the holotype specimen, not the enantiornithine) was a likely small prey predator based on its descendants (see figures 2-4). This taxon is transitional between tinamous (paleognath) and seriemas (neognath). Even though the best data is the crude drawing, it serves well to distinguish this key taxon.

Along with other
toothed birds, like Ichthyornis, Yanornis (Fig. 1, the holotype IVPP V 12558, not the other specimens) nests between paleognaths and neognaths.  Specifically it nests between primitive tinamous and derived seriemas (Fig. 2) in the large reptile tree (LRT, 1085 taxa, still not yet updated).

Yanornis martini holotype (IVPP V12558, Zhou and Zhang 2001; Early Cretaceous) as originally traced and reconstructed by moving those traced lines back to in vivo positions. This is a euornithine bird with several traits retained by living birds not shared with the STM9-52 specimen. The pygostyle appears here by convergence with other Cretaceous birds.

Phylogenetically,
Yanornis is the proximal outgroup taxon to the post-Cretaceous toothless birds and it a sister also gave rise to all extant neognath birds. The bony teeth are derived as known outgroup tinamou taxa do not have teeth.

Figure 2. The serieam (genus: Cariama) is the closest taxa to Yanornis in the LRT and one of the most primitive of all neognaths. The two resemble one another in most details, but Cariama lacks teeth, has a retracted naris and an elevated pedal digit 1.

 

The seriema (genus: Cariama)
is the closest taxa to Yanornis in the LRT and one of the most primitive of all neognaths. The two resemble one another in most details, but Cariama lacks teeth, has a retracted naris, a short pedal 2.1 and an elevated pedal digit 1 among other differences.

Cariama cristatus (Linneaus 1766) is the extant seriema, a grasslands predator from South America. It flies only to escapte predators. Here it is basal to the flamingo, Phoenicopterus.

By the way,
Late Cretaceous Vegavis is now the last common ancestor of all extant birds, contra my earlier results with fewer taxa and more mistakes. Moreover, with Yanornis in the Early Cretaceous, it would not be surprising to find more ´Euornithes in the Cretaceous.

References
Linneaus C 1766. Systema naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Tomus I. Editio duodecima, reformata. Holmiae. (Laurentii Salvii).: 1-532.
Zhou Z. and Zhang F. 2001. Two new ornithurine birds from the Early Cretaceous of western Liaoning, China. Chinese Science Bulletin, 46 (15), 1258-1264.

A fresh reconstruction of Pelagornis nests it with Macronectes

Updated October 12, 2017 with a longer maxilla and a shorter mandible and a new nesting. 

Pelagornis chilensis (Lartet 1857, Mayr and Rubilar-Rogers 2010; Miocene; MNHN SGO.PV 1061; Fig. 1) is an extinct giant soaring bird here related to Macronectes, the giant Southern petrel (Fig. 2). Bony, not true teeth, developed along the jaw margins. The external naris was divided by bone.

Mayr and Rubilar-Rogers reported,
“We finally note that the phylogenetic affinities of bony-toothed birds still have not been convincingly resolved.” I made a fresh reconstruction (Fig. 1) and tested it against a long list of Cretaceous and post-Cretaceous birds to see where it nests.

FIgure 1. Pelagornis, new reconstruction of skull along with overall reconstruction from Mayr and Rubilar-Rogers

Pelagornis is an earlier larger version of
the large soaring sea birds, the petrels (Figs. 2, 3), not far from New World vultures.

Figure 2. Macronectes, the Southern giant petrel, in vivo.

Figure 3. Macronectes giganteus, the extant Southern giant petrel. Note the long maxilla. 

My earlier error was realized
when birds with long maxillae, like Macronectes, starting appearing in the LRT.

References
Lartet E 1857. Note sur un hum´erus fossile d’oiseau, attribu ´e `a un tr `es-grand palmip`ede de la section des Longipennes. Comptes rendus hebdomadaires des S´eances de l’Acad´emie des Sciences (Paris) 44:736–741.
Mayr G and Rubilar-Rogers D 2010. Osteology of a new giant bony-toothed bird from the Miocene of Chile, with a revision of the taxonomy of Neogene Pelagornithidae. Journal of Vertebrate Paleontology 30(5):1313-1340.

wiki/Pelagornis

A new look at Jidapterus (basal azhdarchid pterosaur)

Wu, Zhou and Andres 2017
bring us long anticipated details on Jidapterus (Early Cretaceous, Dong, Sun and Wu 2003) which was previously presented as a small in situ photograph lacking details. Even so a reconstruction could be made (Fig. 1). Coeval larger tracks (Elgin and Frey 2011) have been matched to that reconstruction.

Figure 1. Jidapterus matched to the Gansu, Early Cretaceous pterosaur tracks. The trackmaker was one-third larger than the Jidapterus skeleton.

Of interest today
is the fact that Jidapterus was originally and, so far, universally considered toothless. Its specific name, J. edentatus, refers to that condition. Wu, Zhou and Andres 2017 produced tracings (Figs. 2, 3) of the rostrum that are also toothless. However, they are crude and appear to miss the premaxilla and maxilla sutures, the palatal elements… and maybe some teeth. Those jaw rims are not slippery smooth like those of Pteranodon. Outgroups in the large pterosaur tree (LPT), all have tiny teeth.

Figure 2. Rostrum of Jidapterus (RCPS-030366CY) and traced according to Wu et al. and colorized using DGS to reveal skull sutures and possible teeth. See figure 3 for details. What Wu, Zhou and Andres label the  “low ridge of rostrum” is here identified as the rostral margin above the palatal portion. 

The cladogram of Wu, Zhou and Andres
lacks dozens of key taxa found in the LPT that separate azhdarchids from convergent tapejarids and shenzhoupterids. In the LPT giant azhdarchids arise from tiny toothy azhdarchids once considered Pterodactylus specimens… and these, in turn are derived from tiny and mid-sized dorygnathids in the Middle Jurassic.

What Wu, Zhou and Andres label the  “low ridge of rostrum”
is here identified as the rostral margin rim at the edge of the palate.

Figure 3. Focus on the rostral tip of Jidapterus shown in figure 2. Are these teeth? You decide. I present the data. 

As in all pterosaurs
each premaxilla of Jidapterus has four teeth according to this data.

Are these tiny teeth?
Or are they tiny occlusions and/or chisel marks. Let’s get even better closeups to figure this out. Phylogenetic bracketing indicates either tiny teeth or edentulous jaws could be present here.

References
Dong Z, Sun Y and Wu S 2003. On a new pterosaur from the Lower Cretaceous of Chaoyang Basin, Western Liaoning, China. Global Geology 22(1): 1-7.
Elgin and Frey 2011. A new azhdarchoid pterosaur from the Cenomian (Late Cretaceous) of Lebanon. Swiss Journal of Geoscience. DOI 10.1007/s00015-011-0081-1
Wu W-H, Zhou C-F and Andres B 2017. The toothless pterosaur Jidapterus edentus (Pterodactyloidea: Azhdarchoidea) from the Early Cretaceous Jehol Biota and its paleoecological implications. PLoS ONE 12(9): e0185486.

wiki/Jidapterus

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.

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.

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.

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. 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.

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