Can the LPT identify a pterosaur known only by its palate (and a few cervicals)?

Summary for those in a hurry:
Once the phylogeny of this specimen was determined (after considering all options in the LPT), the stratigraphic age of this specimen turned out to be the real surprise.

Wang et al. 2008
described a 22cm pterosaur skull exposed in palatal view (Fig. 1) from the Early Cretaceous Jiufotang Formation of Liaoning, China. Hongshanopterus lacustris (IVPP V14582) was considered a subadult individual. The robust, triangular teeth were flattened inside and out like those of other istiodactylids, but unlike other istiodactylids, the tooth row extended beyond the first third of the skull and in having some premaxillary teeth curved like sharp hooks.

Figure 1. Hongshanopterus in situ compared to Darwinopterus and Wukongopterus.

Figure 1. Hongshanopterus in situ compared to Darwinopterus and Wukongopterus. Not an istiodactylid, but a wukongipterid. Here all are shown about half life size.

Witton 2012
nested Hongshanopterus in an unresolved clade with Pteranodon, Coloborhynchus and Haopterus.

Kellner et al. 2019 again
nested Hongshanopterus basal to the clade Istiodactylidae.

By contrast
the large pterosaur tree (LPT, 251 taxa) nested Hongshanopterus between the wukongopterids, Wukongopterus and Kupengopterus, far from any istiodactylids. It takes 5 extra steps to force fit Hongshanopterus in the base of the Istiodactylidae (and that’s using just the few characters visible in Hongshanopterus).

That makes Hongshanopterus the largest and latest surviving
wukongopterid (Fig. 2), a clade otherwise restricted to the Middle to Late Jurassic and a clade famous for having a ‘pterodactyloid’-grade skull with a more primitive long-trailed post-crania.

Figure 1. Click to enlarge. The five specimens of Darwinopterus to scale and in phylogenetic order preceded by six more primitive taxa. The ZMNH 8802 specimen is a female associated with an egg. The others genders shown are guesses by Lü et al. 2011a. Note the skull did not elongate, it actually shrank in the vertical dimension, probably reducing its weight. The female is crestless because it is the most primitive of the five known Darwinopterus specimens. The odds that the remaining four specimens are all males is relatively small.

Figure 2. The five specimens of Darwinopterus to scale and in phylogenetic order preceded by six more primitive taxa. The ZMNH 8802 specimen is a female associated with an egg. The others genders shown are guesses by Lü et al. 2011a. Note the skull did not elongate, it actually shrank in the vertical dimension, probably reducing its weight. The female is crestless because it is the most primitive of the five known Darwinopterus specimens. The odds that the remaining four specimens are all males is relatively small.

A clade member,
Darwinopterus, was considered a transitional taxon leading to pterodactyloid-grade pterosaurs. Adding more taxa, as in the LPT, does not support that hypothesis. At present Darwinopterus is a terminal taxon leaving no descendants. Hongshanopterus is the only wukongopterid (so far) to make it into the Early Cretaceous… and it has the largest skull.

Figure 2. Click to enlarge. Anurognathids to scale. The adult of the IVPP embryo is 8x the size of the embryo, as in all other tested adult/embryo pairings.

Figure 3. Click to enlarge. Anurognathids to scale. The adult of the IVPP embryo is 8x the size of the embryo, as in all other tested adult/embryo pairings.

Only a few basal pterosaurs survived into the Cretaceous.
The giant anurognathid embryo, IVPP V13758  (Fig. 3) is the only other basal pterosaur known at present to survive into the Cretaceous.


References
Kellner AWA et al. (6 co-authors) 2019. First complete pterosaur from the Afro-Arabian continent: insight into pterodactyloid diversity. Nature.com/ScientificReports 9:17875. PDF
Wang X, de Almeida Campos D, Zhou Z and Kellner AWA 2008. A primitive istiodactylid pterosaur (Pterodactyloidea) from the Jiufotang Formation (Early Cretaceous), northeast China. Zootaxa. 1813: 1–18.
Witton MP 2012. “New Insights into the Skull of Istiodactylus latidens (Ornithocheiroidea, Pterodactyloidea)”. PLoS ONE. 7 (3): e33170.

wiki/Hongshanopterus
wiki/Wukongopteridae

Misinformation on the palate of Kunpengopterus

Cheng et al. 2017 present
a new complete but slightly damaged specimen of Kunpengopterus, IVPP V 23674.

The new Kunpegnopterus IVPP V 23674.

The new Kunpegnopterus IVPP V 23674.

Cheng et al. provided a new palate reconstruction
that could use a little DGS to better inform the reader and the the authors (Fig. 2, 3). Cheng et al. think they have found some new medial projections toward the back of the palate. Actually they are looking at broken off lateral pieces of the ecto-palatine (ectopterygoid fused to palatine).

Fig. 2. The skull of IVPP V 23674 colorized using DGS alongside the original description.

Fig. 2. The skull of IVPP V 23674 colorized using DGS alongside the original description.

And
here’s a closeup of the palate in dorsal view (Fig. 3). They relied on Wellnhofer 1978 for palate identification. That was when the anterior palate was considered the palatine as it seems to be here, but perhaps fused to the maxilla??. That must be the revision shown here based on Kellner 2013, which I have not read. Ever since Peters 2000, by comparison with Macrocnemus (acknowledged in Kellner 2013), and later by Osi et al. 2010, looking at Dorygnathus, the entire pterosaur palatal plate has been considered the maxilla, as it is here using colors (Fig. 3).

Fig. 3 Kunpengopterus IVPP V 23674 palate in dorsal view alongside original interpretation. Watch out for those broken bones. They sometimes end up in places a wee bit from their origins.

Fig. 3 Kunpengopterus IVPP V 23674 palate in dorsal view alongside original interpretation. Watch out for those broken bones. They sometimes end up in places a wee bit from their origins. And don’t you just hate 1 point lines telling you where the bones are? Colors are much more informative!

It’s really tough
when the broken bone appears to follow the contours of the unbroken bones, as they do here (Fig. 3). That’s where it helps to know the pattern of the palate in ALL pterosaurs. So exceptions like this can be reexamined, looking for the cracks that should not be there.

In similar fashion, here’s a pelvis
(Fig. 4) from the same specimen that appeared to Cheng et al to have a really deep pubis when the reality is more mundane.

Figure 4 Kunpengopterus pelvis with DGS colors identifying the anterior ilium detached from the posterior ilium and the false deep pubis.

Figure 4 Kunpengopterus pelvis with DGS colors identifying the anterior ilium detached from the posterior ilium and the false deep pubis. Note the original drawing in figure 1 that extends the pubis too deep by incorporating the inverted prepubis that match the contours of the ischium. 

References
Cheng X, Jiang S-X, Wang X-L, Kellner AWA 2017. New anatomical information of the wukongopterid Kunpengopterus sinensis Wang et al., 2010 based on a new specimen. PeerJ 5:e4102; DOI 10.7717/peerj.4102
Peters D 2000. A Redescription of Four Prolacertiform Genera and Implications for Pterosaur Phylogenesis. Rivista Italiana di Paleontologia e Stratigrafia 106 (3): 293–336.
Osi A, Prondvai E, Frey E and Pohl B 2010. New Interpretation of the Palate of Pterosaurs. The Anatomical Record 293: 243-258.

SVP 8 – a new wukongopterid from China

In an SVP abstract
Cheng et al. 2015 describe a new wukongopterid, but have several issues to get over.

Figure 1. Click to enlarge. The five specimens of Darwinopterus to scale and in phylogenetic order preceded by six more primitive taxa. The ZMNH 8802 specimen is a female associated with an egg. The others genders shown are guesses by Lü et al. 2011a. Note the skull did not elongate, it actually shrank in the vertical dimension, probably reducing its weight. The female is crestless because it is the most primitive of the five known Darwinopterus specimens. The odds that the remaining four specimens are all males is relatively small.

Figure 1. Click to enlarge. The five specimens of Darwinopterus to scale and in phylogenetic order preceded by six more primitive taxa. The ZMNH 8802 specimen is a female associated with an egg. The others genders shown are guesses by Lü et al. 2011a. Note the skull did not elongate, it actually shrank in the vertical dimension, probably reducing its weight. The female is crestless because it is the most primitive of the five known Darwinopterus specimens. The odds that the remaining four specimens are all males is relatively small.

From the abstract – asterisks have replies below:

The Wukongopteridae comprises a group of long-tailed flying reptiles that combine typical characteristics of basal (non-Pterodactyloidea) and derived pterosaurs (Pterodactyloidea)*. To date, it contains three genera: Wukongopterus, Darwinopterus, and Kunpengopterus**, and potentially also includes Changchengopterus***. Although known from several specimens, there is still a general lack of knowledge about their anatomy, particularly changes during ontogeny.**** Here we report a new specimen (IVPP V17959) that can be referred to the Wukongopteridae based on the presence of a confluent nasoantorbital fenestra, elongated cervical vertebrae and a long tail. The skull and lower jaw are preserved laterally and exposed in left view, lacking the rostral tip. The premaxilla bears a low ossified crest, which is confined to the anterior part of premaxilla and possibly extends to the rostral tip. This differs from Wukongopterus, in which the anterior dorsal margin of the premaxilla is flat, Darwinopterus, which shows a bony premaxillary crest starting anterior to the nasoantorbital fenestra reaching the skull roof*****, and Kunpengopterus, which lacks a cranial crest. The nasal bears a ventral process formed by contralateral fusing elements. Although broken, it is clear that this process almost reaches the ventral margin of the nasoantorbital fenestra. This process differs from the short and inclined nasal process of Darwinopterus and Kunpengopterus. The postcranial skeleton of IVPP V17959 shows signs of an ontogenetically fully mature individual at the time of death, having several elements completely fused such as the scapula and coracoid, the proximal and distal carpal series, and the extensor tendon process of the first wing finger phalanx******. Besides that, opposite prepubes are in close contact with the suture between them partially open suggesting that they are about to fuse. Based on this specimen, it appears that the fusion of the prepubes occurs very late in ontogeny. The new specimen also increases the diversity of the Wukongopteridae and the non-pterodactyloid pterosaurs of the Yanliao Biota, suggesting that it was the most abundant pterosaur group represented in that region during the Jurassic.”

*So do anurognathids (just ask Brian Andres).

** The large pterosaur tree also includes Pterorhynchus, Archaeoistiodactylus and Jianchangnathus in that clade, as more basal members.

***Only the referred specimenPMOL-AP00010, not the much smaller holotype, CYGB-0036. which is closer to Sordes..

**** There should be few to no changes during ontogeny as pterosaurs are known to grow (except for their crests) isometrically, which is why many (hatchlings of the crow-sized and larger pterosaurs) can fly upon hatching.

***** Some Darwinopterus do not have a premaxillary crest.

****** Fusion is more dependent on phylogeny, not ontogeny. Remember, these are lepidosaurs.

It is worthwhile to put all wukongopterid specimens into a phylogenetic analysis. There is phylogenetic variety just in Darwinopterus, for example.

References
Cheng X et al. 2015. 
Description of a new wukongopterid pterosaur with a different type of premaxillary crest from the Jurassic of China and its implications for ontogeny. Journal of Vertebrate Paleontology abstracts.