Forfexopterus: a Huanhepterus sister

Boy, it’s been a long time
since we’ve looked at a new pterosaur. Several months, perhaps… maybe longer…

Figure 1. Forfexopterus reconstructed. Note the metacarpals: 1>2>3, shared with Ardeadactylus. The rostrum tip is off the matrix.

Figure 1. Forfexopterus reconstructed. Note the metacarpals: 1>2>3, shared with Ardeadactylus. The rostrum tip is off the matrix. Note the difference between the actual fingers and the traced fingers by Jiang et al. The lack of precision in the Jiang et al. tracing, despite it being traced from a photograph, is a little disheartening.

Jiang et al. 2016
present a new disarticulated, but largely complete Early Cretaceous pterosaur, Forfexopterus jeholensis (Figs. 1–3). Jiang et al. consider their new find an ‘archaeopterodactyloid’ based on the ‘long metacarpus and reduced mt5’–but those are convergent traits in four pterodactyloid-grade clades. The large pterosaur tree (LPT) nests Forfexopterus near the base of the azhdarchid clade, which arises from the Dorygnathus clade, specifically nesting between Ardeadactylus and Huanhepterus + Mesadactylus (BYU specimen, not the anurognathid with the same name).

Figure 1. Forfexopterus original tracing, colors added.

Figure 2. Forfexopterus original tracing, colors added. See how simple colors ease the chaos of the roadkill fossil.

Unfortunately 
the Jiang et al. phylogenetic analysis suffers from taxon exclusion. They consider the Archaeopterodactyloidea to be composed of Germanodactylidae, Pterodactylus, Ardeadactylus. Gallodactylidae and Ctenochasmatidae. Those members are only monophyletic if the clade also includes Dorygnathus in the LPT, which was not the intention of the authors. It’s been awhile, but let us recall that the former clade “Pterodactyloidea” had four separate origins in the LPT, two from Dorygnathus (Ctenochasmatidae and Azhdarchidae) and the rest from Scaphognathus which was, in turn, also derived from Dorygnathus through several intervening transitional taxa.

Figure 2. Forfexopterus compared to sisters Huanhepterus and Ardeadactylus and the BYU specimen of Mesadactylus.

Figure 3. Forfexopterus compared to sisters Huanhepterus and Ardeadactylus and the BYU specimen of Mesadactylus.

Forfexopterus
has the slender proportions of Huanhepterus and Ardeadactylus. The rostrum was longer and lightened with several fenestra, one of which was likely a naris. Metacarpals 1–3 were longer medially, the opposite of basal pterosaurs. That trait lines up the joints in m1-3. Manual 4.2 is sub equal to m4.1, unique to this clade and atypical for pterosaurs in general.  Atypical for smaller members of this clade, but typical for larger members (like Jidapterus, but evidently not Huanhepterus (data comes from awkwardly produced original drawing)), the scapula was subequal to the coracoid and would have articulated with a notarium, which is not preserved, or is still largely buried (Fig. 2).

Shorthand suggestion (again)
There are two ways you can label a tetrapod phalanx:

  1. ph3d4 = phalanx 3, digit 4 (manus or pes? as shown in figure 2 above) or
  2. m4.3 = manual 4th digit, 3rd phalanx

Jiang et al. labeled their illustration using #1. You may find that method cumbersome and space consuming. I use and encourage others to use #2, the shorthand version.

When you check out the
Wikipedia page on Forfexopterus, the link to Archaeopterodactyloidea references three papers with Dr. Brian Andres as a co-author including his dissertation on
Sytematics of the Pterosauria. It’s great that PhD candidates tackle large projects. It’s hard work that makes them study their subject and prove their mettle. However, by definition, PhD candidates are not experts. They want to become experts by creating a dissertation, but they come to their projects naive, trusting the literature and beholding to their professors. These are all potential problems, as we talked about earlier.

In like manner, 
for my second paper (Peters 2000) I came to the project naive and trusting the literature. Judging from a vantage point, 17 years later, my observations were not those of an expert. Even so, I hit the mark with regard to pterosaur origins despite the many errors in that paper that have been corrected here and at ReptileEvolution.com. The nesting of pterosaurs apart from archosaurs and close to Macronemus, Tanystropheus, Langobardisaurus, Cosesaurus, Sharovipteryx and Longisquama has been validated and cemented by the large reptile tree (LRT). No other candidate taxa have ever been shown to be closer (= produce a gradual accumulation of derived traits). Attempts at correcting the observational errors in academic publications have been rejected by the referees who don’t want any more evidence published that pterosaurs are not dinosaur kin — or that tiny Solnhofen pteros are not babies.

Unfortunately
the Andres dissertation fails to produce a cladogram in which a gradual accumulation of traits can be traced in all derived taxa. For instance, anurognathids are basal to pterodactyloids in the Andres cladogram and the clade Archaepterodactyloidea was recovered. The Andres dissertation shortcoming can be attributed to taxon exclusion. By contrast, the LPT minimizes taxon exclusion by including many specimens ignored by Andres and other prior workers including multiple species within several genera and all those sparrow- and hummingbird-sized Solnhofen specimens. I know pterosaur workers are loathe to admit it, or recognize it, but those extra specimens are key to understanding pterosaur interrelations.

If you don’t look, you’ll never see.
If you don’t ask, you’ll never find out. Fellow pterosaur workers, don’t keep your blinders on. Expand your taxon lists to include a wider gamut of specimens.

This is Science.
When workers publish and referee allow manuscripts to be published they are judging the work fit for print. At that point they have stated their case. If the work stands up to rigorous scrutiny, then it will be cherished. If the work has flaws, then it’s up to fellow workers to expose those flaws for the good of Science.

References
Andres BBB 2010. Systematics of the Pterosauria. Dissertation. Yale University. p. 366.
Jiang S, Cheng X, Ma Y and Wang X 2016. A new archaeopterodactyloid pterosaur from the Jiufotang Formation of western Liaoning, China, with a comparison of sterna in Pterodactylomorpha. Journal of Vertebrate Palaeontology: e1212058.
Peters D 2000. A Redescription of Four Prolacertiform Genera and Implications for Pterosaur Phylogenesis. Rivista Italiana di Paleontologia e Stratigrafia 106 (3): 293–336.

wiki/Forfexopterus
wiki/Archaeopterodactyloidea

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Dr. David Unwin on pterosaur reproduction – YouTube

Dr. David Unwin’ talk on pterosaur reproduction 
was recorded at the XIV Annual Meeting of the European Association of Vertebrate Palaeontologists, Teylers Museum, Haarlem, Netherlands and are online as a YouTube video.
Dr. Unwin is an excellent and engaging speaker.
However, some of the issues Dr. Unwin raises have been solved at www.ReptileEvolution.com
The virtual lack of calcite in pterosaur eggs were compared to lepidosaurs by Dr. Unwin, because pterosaurs ARE lepidosaurs.  See: www.ReptileEvolution.com/reptile-tree.htm
Lepidosaurs carry their eggs internally much longer than archosaurs, some to the point of live birth or hatching within hours of egg laying. Given this, pterosaurs did not have to bury their eggs where hatchlings would risk damaging their fragile membranes while digging out. Rather mothers carried them until hatching. The Mrs. T external egg was prematurely expelled at death, thus the embryo was poorly ossified and small.
Dr. Unwin ignores the fact that hatchlings and juveniles had adult proportions as demonstrated by growth series in Zhejiangopterus, Pterodaustro and all others, like the JZMP embryo (with adult ornithocheirid proportions) and the IVPP embryo (with adult anurognathid proportions).
Dr. Unwin also holds to the disproved assumption that all Solnhofen sparrow- to hummingbird-sized pterosaurs were juveniles or hatchlings distinct from any adult in the strata. So they can’t be juveniles (see above). Rather these have been demonstrated to be phylogenetically miniaturized adults and transitional taxa linking larger long-tailed dorygnathid and scaphognathid ancestors to larger short-tailed pterodactyloid-grade descendants, as shown at: www.ReptileEvolution.com/MPUM6009-3.htm
Thus the BMNH 42736 specimen and Ningchengopterus are adults, not hatchlings. And the small Rhamphorhynchus specimens are also small adults.

SVP 11 Pterosaur pelvic morphology

Frigot 2015 
provides general information about pterosaur pelves using principal component analysis, similar to that of Bennett 1995, 1996. I hope it works out better for Ms. Frigot.

From the abstract
“Pterosaurs have modified the basic triradiate amniote pelvis, extending the ilium into elongate processes both anterior and posterior to the acetabulum. While pterosaurs are now generally accepted to move quadrupedally on the ground*, many hypotheses exist regarding the diversity of gaits and terrains exploited across Pterosauria and how this may be correlated with the shifts in body plan found at the base of the monofenestratans and of the pterodactyloids. Early attempts to bring comparative anatomy to bear upon the topic have been largely descriptive of pelvic shape across the clade. I attempt to rectify this by providing a geometric morphometric analysis of a phylogenetically diverse sample of pterosaur pelves. Using landmark-based methods, shape was captured at the bone margins and acetabulum, with a view to capturing surfaces available for muscle attachment. These landmarks were analyzed using principal components analysis (PCA). Principal components 1 and 2 distinguish well between genera, reducing possible concerns over the role of taphonomy and ontogeny in determining shape**. It is not apparent whether the lack of a phylogenetic trend across shape space is due to small sample size or a high degree of evolutionary plasticity, highlighting the need for a greater sample size. However, with this support for a biological signal in the data, subsequent steps can be made that focus on biomechanical and locomotor analyses using detailed anatomical observations. We can then try to identify how pelvic disparity might have led to a diversity of locomotor styles in this most unique taxon.”***

*That’s traditional thinking. Many pterosaur tracks indicate bipedal locomotion.
**Ontogeny does not change pelvis shape because pterosaurs grew isometrically.
***So, sorry… no taxa or conclusions here.

References
Frigot RA 2015. The pterosaurian pelvis. An anatomical view of morphological disparity and implications for for locomotor evolution.

Trees of Life: Birds and Pterosaurs

Yale’s Richard Prum recently announced that the Tree of Life of Birds is almost complete. A genomic analysis of 198 species of birds was published in the Oct. 7 edition of the journal Nature. Prum reported, ““In the next five or 10 years, we will have finished the tree of life for birds.” I presume that means fossil taxa will also be included and scored by morphological traits because genes (genomic traits) are not available.

It is not the first time…
Trees of Life for Birds were announced earlier here, here, here and here.

Having been through a similar study, I support all such efforts. AND I will never attempt to add any but a few sample birds to the large reptile tree. Others have better access to specimens and they have a big head start on the process.

Unfortunately,
some workers have ignored the pterosaur tree of life. Recently Mark Witton ignored isometric growth patterns in pterosaurs to agree with Bennett (2013) that the genus Pterodactylus includes tiny short-snouted forms, mid-sized long-snouted forms (including the holotype, of course) and large small-heron-like forms. Witton reports, “Speaking of adulthood, it was also only recently that we’ve obtained a true sense of how large Pterodactylus may have grown. We typically imagine this animal as small bodied – maybe with a 50 cm wingspan – but a newly described skull and lower jaw makes the first unambiguous case for Pterodactylus reaching at least 1 m across the wings (Bennett 2013).”

We looked at Bennett’s paper earlier in a three part series that ended here. The taxon Witton refers to is actually just a wee bit larger than the holotype and is known from a skull, so wingspread can only be guessed. The tiny short-snouted forms are actually derived from the short-snouted scaphognathids as shown here.

The Pterodactylus lineage and mislabeled specimens formerly attributed to this "wastebasket" genus

Figure 1. Click to enlarge. The Pterodactylus lineage and mislabeled specimens formerly attributed to this “wastebasket” genus. Others have split the largest specimens of Pterodactylus from the others without employing a phylogenetic analysis.

You might recall
that one of the largest complete Pterodactylus specimens (Fig. 1) recovered by the large pterosaur tree was mistakenly removed from this genus and lumped with Ardeadactylus, a basal pre-azhdarchid, all without phylogenetic analysis.

Agreeing with Bennett,
Witton deletes some taxa that actually belong to this genus, while accepting others that do not belong, all based on eyeballing specimens without a phylogenetic analysis that includes a large gamut of specimens (that does not delete the tiny forms). Eyeballing taxa is not the way to handle lumping and splitting. Phylogenetic analysis is. We looked at the Pterodactylus wastebasket problem here.

References
Bennett  SC 2012 [2013]. New information on body size and cranial display structures of Pterodactylus antiquus, with a revision of the genus. Paläontologische Zeitschrift (advance online publication) doi: 10.1007/s12542-012-0159-8
http://link.springer.com/article/10.1007/s12542-012-0159-8

News on the Origin of Pterosaurs on YouTube

I just uploaded a pterosaur origins video on YouTube. Click here to view it.

Click to view this "Origin of Pterosaurs" video on YouTube.

Click to view this “Origin of Pterosaurs” video on YouTube. 17 minutes long. 

Back to Cuspicephalus: Germanodactylid? or Wukongopterid?

Earlier we looked at the gracile skull of Cuspicephalus which nested with Germanodactylus B St 1892 IV 1 in the large pterosaur tree.

Today we revisit this taxon after the publication of Witton et al. 2015, which attempted to related Cuspicephalus to Darwinopterus and the wukongopterids.

Cuspicephalus scarfi

Figure 1. Cuspicephalus scarfi. Click to enlarge. Note the round exoccipital process at the back of the skull. Germanodcatylids have these. Wukongopterids do not. Witton thinks that bone is an artifact.

I have rarely seen a paper with such a bogus foundation…

  1. Witton et al. support the ‘modular’ evolution of pterosaurs at the base of the Pterodactyloidea. Earlier we learned that with the simple addition of taxa (which other workers continue to avoid) there are four origins for pterodactyloid-grade pterosaurs, all following phylogenetic miniaturization, a process that happens often in reptile evolution. We also learned that there is no such thing as ‘modular’ evolution with half the body evolving and waiting for the other half to catch up. In the case of wukongopterids, the other half never developed pterodactyloid-grade traits. Wukongopterids were a terminal taxon. The non-modular evolution of long tails to short tails happened several other times at several other nodes in the pterosaur cladogram (including in the anurognathids).
  2. With several distinct genera and specimens now nesting close to Darwinopterus robustus within the Wukongopteridae, no attempt was made to figure out which of these specimens were more basal and which were more derived — as shown in the large pterosaur tree.
  3. Witton et al. support a monophyletic “Monosfenestrata” which, to them, includes pterodactyloids + wukongopterids, a tree topology that is not supported by any other published studies. In the large pterosaur tree, wukongopterids, like anurognathids, convergently developed some pterodactyloid-grade traits and not others, then left no descendants.
  4. Witton et al. did not produce their own skull tracings, but rely on cartoonish and inaccurate versions of prior work by others (apparently often by Bennett 1996). Few to no skull sutures are shown and certain inaccuracies are present.
  5. Witton et al. are not critical of the cladistic work of others (Andres et al., 2014; (Lü et al., 2010; Tischlinger and Frey, 2014), nor do they offer support for the matrix they preferred (Unwin 2003). Seems less scientific than one would like to see here. Or did they not want to do the work? Or make enemies?
Figure 2. Cuspicephalus compared to Darwingopterus and to Germanodactylus, all to scale.

Figure 2. Cuspicephalus compared to Darwingopterus and to Germanodactylus, all to scale. Click to enlarge. The large reptile tree nests Cuspicephalus with Germanodactylus. Witton et al. report a closer relationship to Darwinopterus. The presence of large exoccipital ‘ears’, an extended cranium, a pointed rostrum, a pointed ventral orbt, an alignment of the rostral crest and antorbital fenestra anterior margin all argue for the present hypothesis. The longer antoribital fenestra developed by convergence in Darwinopterus and Cuspicephalus.

Granted,
wukongopterid skulls are indeed very similar to those of germanodactylids (Fig. 2). Both clades also offer a wide variety of shapes and sizes.

With regard to a key trait
in Cuspicephalus scarfi (MJML K1918) from Witton et al. 2015: The exoccipital processes are unexpanded: they look relatively large on MJML K1918, but this is largely an artefact of distortion around the occipital region, and they are not as prominent as those of Germanodactylus or dsungaripterids.

Actually
in Cuspicephalus the exoccipitals are just as big, if not bigger relative to skull height (Fig. 2).

In the large pterosaur tree
Cuspicephalaus nests with B St 1892 IV 1, n61 in the Wellnhofer (1970) catalog, which nests with two headless taxa, Wenupteryx (MOZ 3625) and the so-called “Crato azhdarchide (SMNK PAL 3830)”

From Witton et al. “Our assessment suggests that wukongopterid skulls can be distinguished from other Jurassic monofenestratans by not only lacking the well-documented cranial  synapomorphies of pterodactyloid clades, but also through a unique combination of characters (Darwinopterus, Gemanodactylus and Cuspicephalus = D, G and C):

  1. Striated bony crest lower than the underlying prenarial rostrum, with sloping anterior margin – actually lower in G.
  2. Anterior crest terminates in the posterior region of the prenarial rostrum, closer to the anterior border of the nasoantorbital fenestra than the jaw tip – note the crest starts more anteriorly in D
  3. Reclined, but not sub-horizontal, occipital regions leans more in G.
  4. Piriform (pear-shaped) orbitbut in G and C the orbit is sharply angled ventrally
  5. Convex anterodorsal orbital marginmore convex in G + C.
  6. Short nasal processonly in D.
  7. Unexpanded exoccipital processesonly in D.
  8. Concave dorsal skull surfacenot on G, D or C.
  9. Straight ventral skull surfacepresent on G, D and C.
  10. Nasoantorbital fenestra over 50% of jaw length – on D and C
  11. Small, equally sized alveoli – only on C, larger teeth on D and G.
  12. First alveolus pair located on anterior face of jaw, with mandible over-bitten by first premaxillary tooth pair – present on G, D and C
  13. Regular tooth spacing – only on D
  14. Interalveolar spacing generally greater than tooth length – only on D
  15. Dentition extends under anterior half of the nasoantorbital region – only on G and C
  16. Relatively slender, sharply pointed conical teeth – only on C.

Chronology
Cuspicephalus is Kimmeridgian (Late Jurassic) in age. So is Germanodactylus (Kimmeridigian/Tithonian). Darwinopterus is late Middle Jurassic (Bathonian/Oxfordian) in age. No wukongopterids are found in Late Jurassic deposits. So far…

I can see why there is confusion here. 
The skulls are very similar in overall morphology. But the weight of evidence appears to lend weight to a Germanodactylus relationship for Cuspicephalus. If Witton et al. had made more precise tracings and reconstructions, if they had used a valid tree topology that included tiny pterosaurs, if they had not discounted the presence of exoccipital processes on Cuspicephalus, then I think they would have come up with a nesting that echoed that of the large pterosaur tree.

An outlandish suggestion based on a cladogram
We have a large germanodactylid skull without a body (Cuspicephalus) and we have a large germanodactylid post-crania without a skull (the Crato Azhdarchide). Although they are separated somewhat in time, they are sister taxa. Wonder how well the real skull and real post-crania would match up with these two…

Diopecephalus = P. longicollum = Ardeadactylus. Normannognathus is in the box in the lower left.

Figure 3. Witton et al. also attempted to resolve the relationships of Normannognathus without success. Here it is in the box at lower left. Phylogenetic analysis nests it with Diopecephalus = P. longicollum = Ardeadactylus.

Normannognathus
Witton et al. also considered the problem of the placement of Normannognathus (Fig. 3). Earlier we looked at the phylogenetic relationships of Normannognathus (Buffetaut et al. 1998;  MGC L 59’583) known from a toothy, curved rostrum and crest. While Witton et al. considered the problem too difficult to solve, several years ago Normannognathus was matched to the big Pterodactylus longicollum (SMNS-56603, No. 58 of Wellnhofer 1970), which was not considered by Witton et al.

References
Andres B, Clark J, Xu X. 2014. The earliest pterodactyloid and the origin of the group. Current Biology 24: 1011-1016.
Bennett SC 1996. Year-classes of pterosaurs from the Solnhofen limestones of Germany: taxonomic and systematic implications. Journal of Vertebrate Paleontology 16:432–444.
Lü JC, Unwin DM, Jin X, Liu Y, Ji Q. 2010. Evidence for modular evolution in a long-tailed pterosaur with a pterodactyloid skull. Proceedings of the Royal Society B 277: 383-389.
Tischlinger H and Frey E 2014. Ein neuer Pterosaurier mit Mosaikmerkmalen basaler und pterodactyoider Pterosaurier aus dem  Ober-Kimmeridgium von Painen (Oberpfalz, Deutschland) [A new pterosaur with moasic characters of basal and pterodactyloid Pterosauria from the Upper Kimmeridgian of Painten (Upper Palatinate, Germany)]. Archaeopteryx 31: 1-13.
Witton MP, O’Sullivan M and Martill DM 2015. The relationships of Cuspicephalus scarfi Martill and Etches, 2013 and Normannognathus wellnhoferi Buffetaut et al., 1998 to other monofenestratan pterosaurs.

 

 

Something new in Eudimorphodon revealed by DGS

Some people are still having trouble with DGS as a technique. They think of it as something that is virtually guaranteed to spook a reconstruction. Instead of increasing confidence that parts have been correctly identified, they have no confidence in work that has the taint of DGS.

Here’s a step-by-step run through DGS on a familiar specimen, Eudimorphodon ranzii. Using DGS enabled the recognition of some oddly long posterior ribs (that were always visible, just ignored) and a wider than deep torso in a pterosaur for which these traits were not otherwise recorded.

Eudimorphdon ranzii (Zambelli 1973, Wild 1978) s a Late Triassic pterosaur known from an articulated crushed skeleton missing feet, tail and most of each wing (Figs. 1-3). Some parts are easy to see and trace, like the skull and sternal complex. Some parts are more difficult like the two pubes (Wild 1978 only found one by combining the two into an oddly broad prepubis),  the pelvis, and the odd arrangement of the posterior ribs.

Eudimorphdon ranzii with post cranial bones colorized.

Figure 1. Eudimorphdon ranzii with post cranial bones colorized.

Step one: Colorize the bones (Fig. 1)
Darren Naish seems to think this is okay if you know which bone is which ahead of time when looking at the specimen and you’re just making a visual presentation. I like to take it one step further and use DGS to segregate bones that are more difficult to identify. Here the pelvis is found. The dorsal ribs will precisely transferred to the reconstruction, not generically applied. As we’ve learned earlier, sometimes pterosaurs have the cross section of a horned lizard.

Figure 2. The colorized bones on a fresh canvas.

Figure 2. The colorized bones on a fresh canvas. Most tetrapods have shorter posterior dorsal ribs, but not here in Eudimorphodon. Lighter tones on the pelvis represent overlying bones, in this case vertebrae. It is important to put a numeral on each vert and rib because it is otherwise easy to become confused.

Step two: Transfer the colorized bones onto a fresh white background (Fig. 2)
Here we’re just trying to put the bones on a fresh canvas. You’ll note some bones are estimates based on vague clues as they appear beneath the sternal complex.

Figure 3. Moving colorized bones into a rough reconstruction.

Figure 3. Moving colorized bones into a rough reconstruction or Eudimorphodon. Here both pelves are shown as they appeared in situ. In figure 1 I jumped the gun and put the parts together.

Step three: Move the colorized bones into a rough assembly (Fig. 3)
Here we’re just trying estimate a body shape to make tracing the colored bones easier.

Figure 4. Lateral, dorsal and cross-sectional views of Eudimorphodon ranzii. Note the overlap of the posterior ribs over the hind limbs and the very wide torso.

Figure 4. Lateral, dorsal and cross-sectional views of Eudimorphodon ranzii. Note the overlap of the posterior ribs over the hind limbs and the very wide torso. The cross section shows the 2nd dorsal ribs and the 23rd. Note the small ischium which could only produce small eggs. A little taller and wider than we thought before. The forelimbs are pretty short relative to the torso.

Step four: Tracing the colorized bones for the final reconstruction. (Fig. 4)
If I just attempted a lateral view I would have missed out on the very broad posterior torso based on the length of the posterior ribs. So I create both a dorsal view and a cross section view. Note that the sternal ribs, rarely found on most pterosaurs, extend laterally to meet the dorsal rib tips in Eudimorphodon. This give it a slightly wider body anteriorly, increasingly wider posteriorly. This is an odd autapomorphy, but it is based on many ribs, so it can’t be ignored. As you can see from the in situ image (Fig. 1) those long posterior ribs were there all the time. They were simply ignored by myself and others.

Eudimorphodon: a little odder than we thought
That torso is odd. Rather than tapering toward the pelvis, as in many other pterosaurs and tetrapods in general, the posterior torso is flat and wide, roofing the femora. My guess it provides a greater volume for eggs or respiration. With such small eggs, more eggs could have been carried by the mother. Note that the predecessor of E. ranzii, MPUM 6009, has a much deeper pelvic opening, likely to produce one large egg at a time. Note the reduction of the pelvis is also reflected in the reduction of the number of sacrals to four or five depending on the connection to the posterior pelvis.

Now
If there is anything wrong with the results here, please let me know. If not feel free to use the technique yourself. I think it works pretty well.

I also don’t make these identifications without entering the taxa into a phylogenetic analysis that typically finds the same traits in sister taxa. Unfortunately posterior ribs are virtually unknown among Triassic and Early Jurassic sisters.

Pterosaur workers haven’t produced too many Eudimorphodon reconstructions, and certainly none that have recovered the oddly long posterior ribs. My earlier reconstructions were given generic ribs. So I did a bad thing. I went along with the paradigm of a tubular pterosaur body without testing that paradigm. While it takes a lot of work for small discoveries such as this, and the results are minor changes, well, I had nothing better to do on a quiet Sunday.

References
Wild R 1978. Die Flugsaurier (Reptilia, Pterosauria) aus der Oberen Trias von Cene bei Bergamo, Italien. Bolletino della Societa Paleontologica Italiana 17(2): 176–256.
Zambelli R 1973. Eudimorphodon ranzii gen.nov., sp.nov. Uno Pterosauro Triassico. Rendiconti Instituto Lombardo Accademia, (rend. sc.) 107: 27-32.
wiki/Eudimorphodon