Sinopterus? or Huaxiapterus? It gets confusing…

A kind reader alerted me to a misidentification here.
The grayscale image (Fig. x) is the ZMNH M 8131 specimen of Huaxiapterus. When a higher resolution image becomes available I will return to this specimen and edit the copy. With that in mind… here is the original blogpost, awaiting an edit.

Figure x. Huaxiapterus ZMNH-M-8131 specimen.

Figure x. Huaxiapterus ZMNH-M-8131 specimen.

 

Thank goodness
for museum numbers.

Today the ZMNH M 8131 specimen first attributed to
Huaxiapterus corollatus (Lü et al. 2006) then renamed Sinopterus corollatus (Zhang et al. 2019; Figs. 1, 2) enters the the large pterosaur tree (LPT, 255 taxa) basal to tapejarids, derived from the Sinopterus atavismus specimen nesting basal to dsungaripterids.

Figure 1. Huaxiapterus corollatus ZMNH M 8131 reconstructed. An alternate m4.1 is provided that looks more like a m4.1 than a metacarpal 4.

Figure 1. Huaxiapterus corollatus ZMNH M 8131 reconstructed. An alternate m4.1 is provided that looks more like a m4.1 than a metacarpal 4.

Sometimes specimens are reassembled slightly wrong.
In this case several long bones were accidentally reversed end-to-end in this otherwise stunning mount. One never knows what the original fossil looked like prior to reassembly. We don’t want to call these ‘fakes’. We do want to be aware of errors and artistic reconstructions as much as is possible.

Figure 2. The ZMNH specimen in situ and somewhat corrected for original perspective issues. The correction makes the wings the same length.

Figure 2. The ZMNH specimen in situ and somewhat corrected for original perspective issues. The correction makes the wings the same length. Be wary of such wonderful-looking fossils. This specimen appears to have been reassembled. Some long bones are reversed end-to-end, which do not affect scoring.

Sinopterus – Huaxiapterus corollatus (Lü et al. 2006; Early Cretaceous, ZMNH M 8131) is another largely complete specimen with confusing nomenclature. This taxon nests at the base of the Tapejara, basal to the Aathal specimen (below). The pelvis is missing. The sternum is among the largest of all pterosaurs. The cervicals are longer creating a taller pterosaur.

From the Lü et al. abstract:
“A new species of tapejarid pterosaur, Huaxiapterus corollatus sp. nov. is erected on the basis of a nearly complete skull and postcranial skeleton from the Lower Cretaceous Jiufotang Formation of Liaoning Province, China. Huaxiapterus corollatus sp. nov. is characterized by a hatchet-shaped rectangular process on the premaxilla, whose short axis is perpendicular to the anterior margin of the premaxillae. Except for this process, other characters of the skull such as the breadth of the snout between the anterior margin of the nasoantorbital fenestra and the anterior margin of the premaxilla are similar to that of Huaxiapterus jii.”

Figure 3. Huaxiaptrus iii and Huaxiapterus corollatus to scale. These two do not nest next to one another in the LPT.

Figure 3. Huaxiaptrus iii and Huaxiapterus corollatus to scale. These two do not nest next to one another in the LPT.

The Lü et al. abstract continues
“Huaxiapterus and a second Chinese tapejarid, Sinopterus, share several unique cranial characters in common with Tapejara and these three genera appear to be more closely related to each other than to other azhdarchoids.

In the LPT azhdarchids nest with dorygnathids, not tapejarids. Adding these taxa missing from prior studies makes this inevitable.

“The Chinese tapejarids (Sinopterus and Huaxiapterus) have relatively elongate skulls and weakly developed cranial crests and seem to be less derived than Tapejara, with its shorter, deeper skull and large cranial crest. Tupuxuarids (Tupuxuara and Thalassodromeus) have often been associated with tapejarids in the family Tapejaridae, but this relationship is controversial because some phylogenetic analyses have supported the pairing of tupuxuarids with Azhdarchidae.”

Adding taxa moves Azhdarchidae away from tupuxuarids.

Figure 4. Tapejaridae in the LPT.

“We propose that Tapejaridae be restricted to Tapejara, Sinopterus and Huaxiapterus.”

The LPT does not support that proposal (Fig. 4). The Tapejaridae remains a monophyletic clade in the LPT derived from dsungaripterids, shenzhoupterids and earlier, germanodactylids… not azhdarchids.


References
Lü JC, Jin XS, Unwin DM, Zhao LJ, Azuma Y and Ji Q 2006. A new species of Huaxiapterus Pterosauria: Pterodactyloidea from the Lower Cretaceous of western
Liaoning, China with comments on the system atics of tapejarid pterosaurs. Acta Geol Sinica English 80: 315-326.
Zhang X, Jiang S, Cheng X and Wang X 2019. New material of Sinopterus (Pterosauria, Tapejaridae) from the Early Cretaceous Jehol Biota of China. Anais da Academia Brasileira de Ciencias 91(2):e20180756. DOI 10.1590/0001-3765201920180756.

wiki/Sinopterus
wiki/Huaxiapterus
reptileevolution.com/tapejaridae.htm

The larger specimen of Sinopterus atavismus enters the LPT basal to dsungaripterids

Many pterosaur fossils attributed to Sinopterus
have been described. They vary greatly in size and shape.

Presently four Sinopterus specimens have been added
to the large pterosaur tree (LPT, 253 taxa). They are all sister taxa, but as in Archaeopteryx, no two are alike, one is basal to the others, which are, in turn, basal to large clades within the Tapejaridae.

  1. Sinopterus dongi (the holotype) nests basal to the Tupuxuara clade.
  2. Sinopterus liui nests in the Tupuxuara clade.
  3. Sinopterus jii (aka Huaxiapterus jii) nests basal to the Tapejara clade.
  4. Sinopterus atavisms (Figs. 1-4; Zhang et al. 2019; IVPP V 23388) nests basal to the Dsungaripterus (Fig. 4) clade, outside the Tapejaridae.
Figure 1. Sinopterus atavismus in situ.

Figure 1. Sinopterus atavismus in situ. IVPP V 23388

From the Zhang et al. 2019 abstract:
“Here, we report on a new juvenile specimen of Sinopterus atavismus from the Jiufotang Formation of western Liaoning, China, and revise the diagnosis of this species.”

Zhang et al. note that several elements are unfused including a humeral epiphysis. Several pits and grooves in the distal ends of the long bones are also pitted and grooved. Normally these would be good indicators in archosaurs and mammals, but pterosaurs are lepidosaurs and lepidosaurs follow distinctly different ‘rules’ for growth (Maisano 2002). As an example, some pterosaur embryos have fused elements. Some giant pterosaurs have unfused elements. Here the new specimen (IVPP 23388) is considered an ontogenetic adult as its size is similar to other phylogenetic relatives.

“Sinopterus atavismus does not present a square-like crest. Moreover the feature that groove in the ventral part of the second or third phalanx of manual digit IV is not diagnostic of the species.”

Zhang et al. are comparing the new larger IVPP specimen to the smaller, previously described (Lü et al. 2016) XHPM 1009 specimen (then named Huaxiapterus atavismus), which they considered conspecific. The XHPM specimen has wing phalanx grooves while the IVPP specimen does not. The shapes of the skulls do not match (Fig. 3) and we know that pterosaurs grew isometrically. Thus these two specimens are not conspecific.

“In the new material, the skull preserves a pointed process in the middle part of the dorsal marginof the premaxillary crest, which is different from other Chinese tapejarids. Considering the new specimen is known from a large skeleton that differed from the holotype, this difference may be related to ontogeny, as the premaxillary crest of the holotype is short and does not extend as long as that of the new specimen.”

These two specimens are not conspecific, so ontogenetic comparisons should not be made.

Figure 2. Sinopterus atavismus reconstruction.

Figure 2. Sinopterus atavismus reconstruction.

From the Zhang et al. 2019 discussion:
“Except for D 2525 which represents an adult individual of Sinopterus (Lü et al. 2006b), all Chinese tapejarid pterosaurs known so far were immature individuals at the time of death. The new specimen (IVPP 23388) shares some features with the holotype of Sinopterus atavismus. The wingspan of the new material is about twice as long as that of the holotype of S. atavismus.”

As mentioned above, the IVPP V 23388 specimen is here considered an adult with unfused bone elements. It needs both a new generic and specific name. The XHPM 1009 specimen (Fig. 3) requires further study.

Figure 3. Sinopterus atavismus size comparison

Figure 3. Sinopterus atavismus size and shape comparison.

The present confusion about the ontogenetic status of pterosaurs 
could have been largely resolved with the publication of “The first juvenile Rhamphorhynchus recovered by phylogenetic analysis” and other papers suppressed by pterosaur referees. Sorry, readers, we’ll have to forge ahead with the venues we have.

Figure 3. Sinopterus atavismus skull restored (gray areas).

Figure 4. Sinopterus atavismus skull restored (gray areas).

Figure 4. Sinopterus atavisms compared to Dsungaripterus to scale.

Figure 5. Sinopterus atavisms compared to Dsungaripterus to scale.

Sinopterus atavismus (Zhang et al. 2019; Early Cretaceous; IVPP V 23388) was originally considered a juvenile member of the Tapejaridae, but here nests as a small adult basal to Dsungaripteridae. The antorbital fenestra is not taller than the orbit. The carpals are not fused. No notarium is present. The antebrachium is robust. The distant pedal phalanges are longer than the proximal pedal phalanges. An internal egg appears to be present (but half-final-size adults were sexually mature according to Chinsamy et al. 2008,)

Sinopterus dongi IVPP V13363 (Wang and Zhou 2003) wingspan 1.2 m, 17 cm skull length, was linked to Tapejara upon its discovery, but is closer to Tupuxuara.

Sinopterus? liui (Meng 2015; IVPP 14188) is represented by a virtually complete and articulated specimen attributed to Sinopterus, but nests here at the base of Tupuxuara longicristatus.

Sinopterus jii (originally Huaxiapterus jii, Lü and Yuan 2005; GMN-03-11-001; Early Cretaceous) is basal to the Tapejara in the LPT, distinct from the other sinopterids basal to Tupuxuara.

Figure 5. Click to enlarge. The Tapejaridae arise from dsungaripterids and germanodactylids.

Figure 5. Click to enlarge. The Tapejaridae arise from dsungaripterids and germanodactylids.

The present LPT hypothesis of interrelationships
appears to be a novel due to taxon inclusion, reconstruction and phylogenetic analysis. If not novel, please let me know so I can promote the prior citation.

Traditional phylogenies falsely link azhdarchids with tapejarids
in an invalid clade ‘Azhdarchoidea‘. The LPT has never supported this clade (also see Peters 2007), which is based on one character: an antorbital fenestra taller than the orbit (that a few sinopterids lack). Pterosaur workers have been “Pulling a Larry Martin” by counting on this one character and by excluding pertinent taxa that would have shown them this is a convergent trait ever since the first cladograms appeared in Kellner 2003 and Unwin 2003.

Figure 1. Gene studies link swifts to hummingbirds. Trait studies link swifts to owlets. Trait studies link hummingbirds to stilts.

Figure x. Gene studies link swifts to hummingbirds. Trait studies link swifts to owlets. Trait studies link hummingbirds to stilts.

Unrelated update:
The stilt, Himantopus (Fig. x) has moved one node over and now nests closer to the hummingbird, Archilochus. Both arise from the Eocene bird, Eocypselus, which also gives rise to the hovering seagull, Chroicocephalus. The long, mud probing beak of the stilt was adapted to probing flowers in the hummingbird. All these taxa nested close together in the LRT earlier.


References
Chinsamy A, Codorniú L and Chiappe LM 2008. Developmental growth patterns of the filter-feeder pterosaur, Pterodaustro guinazui. Biology Letters, 4: 282-285.
Kellner AWA 2003. 
Pterosaur phylogeny and comments on the evolutionary history of the group. Geological Society Special Publications 217: 105-137.
Lü J and Yuan C 2005. 
New tapejarid pterosaur from Western Liaoning, China. Acta Geologica Sinica. 79 (4): 453–458.
Maisano JA 2002. The potential utility of postnatal skeletal developmental patterns in squamate phylogenetics. Journal of Vertebrate Paleontology 22:82A.
Maisano JA 2002.
Terminal fusions of skeletal elements as indicators of maturity in squamates. Journal of Vertebrae Paleontology 22: 268–275.
Peters D 2007. The origin and radiation of the Pterosauria. In D. Hone ed. Flugsaurier. The Wellnhofer pterosaur meeting, 2007, Munich, Germany. p. 27.
Unwin DM 2003. On the phylogeny and evolutionary history of pterosaurs. Pp. 139-190. in Buffetaut, E. & Mazin, J.-M., (eds.) (2003). Evolution and Palaeobiology of Pterosaurs. Geological Society of London, Special Publications 217, London, 1-347.
Wang X and Zhou Z 2003. A new pterosaur (Pterodactyloidea, Tapejaridae) from the Early Cretaceous Jiufotang Formation of western Liaoning, China and its implications for biostratigraphy. Chinese Science Bulletin 48:16-23.
Zhang X, Jiang S, Cheng X and Wang X 2019. New material of Sinopterus (Pterosauria, Tapejaridae) from the Early Cretaceous Jehol Biota of China. Anais da Academia Brasileira de Ciencias 91(2):e20180756. DOI 10.1590/0001-3765201920180756.

wiki/Sinopterus

Dsungaripterus palate news: Chen et al. 2020

Chen et al. 2020 describe 
a perfectly preserved Dsungaripterus palate (Figs. 1, 2) recovered by Young prior to 1964. This is welcome news! Unfortunately, the presentation of their recent ‘discoveries’ perpetuates a few pterosaur myths.

Figure 1. Dsungaripterus palate from Chen et al. 2020 with colors and diagrams (above) from Peters 2000 added. Note only a vestige remains of the lateral process of the palatine. The extent of the jugal is a guess here. Pink = pterygoid. Blue = palatine. Gold = ectopterygoid.  In Chen et al. the line leading toward the abbreviation pl points to the maxilla.

Figure 1. Dsungaripterus palate from Chen et al. 2020 with colors and diagrams (above) from Peters 2000 added. Note only a vestige remains of the lateral process of the palatine. The extent of the jugal is a guess here. Pink = pterygoid. Blue = palatine. Gold = ectopterygoid.  In Chen et al. the line leading toward the abbreviation pl points to the maxilla.

Chen et al. 2020 cite
Osi et al. 2010, which we looked at earlier here. You might remember, Osi et al. thought they had discovered the true identity of palatal elements, but parenthetically acknowledged that Peters 2000 (Fig. 1) had done so a decade earlier. They did not realize others had also done so over a century before.

Prior to Peters 2000  
and ever since Williston (1902) and continuing through Huene 1914, Wellnhofer (1978, 1991) and Bennett (1991, 2001a,b), the solid palatal plate in pterosaurs had been traditionally considered the palatine. That was the orthodox point-of-view.

Virtually ignored,
Newton (1888), Seeley (1901 and Woodward (1902) reported that the solid palatal plate was an outgrowth of the maxilla, not the palatine. Unfortunately, I did not know those citations when Peters 2000 reported that the palatal plate actually originated from the maxilla. I thought I had discovered something! Rather, I had only confirmed work from a century earlier. Workers: it is important to expand your citation list so future workers will not overlook important papers, be they 20 years old or 120 years old.

Germanodactylus and the Dsungaripteridae

Figure 2. Germanodactylus and the Dsungaripteridae. Contra Chen et al. , azhdarchids are not related.

Longtime readers may remember a wide gamut of dozens
of pterosaur and pterosaur ancestor palates (example Fig. 3) illustrated here, and in nine blogposts that followed, so pterosaur palate data has been online for several years.

The diagram illustration by Chen et al. 2020
(Fig. 1) uses the old-fashioned method of identifying bones, with lines leading from somewhere on the bones to outlying abbreviations. No indication of borders or sutures is provided. All the bones in their Dsungaripterus palate appear fused, despite remnants of borders visible in closer view (Fig. 1). More workers are using colors lately because they impart more data.

From the Chen et al. abstract:
“Among the unique features is a lateral process of the pterygoid divided into two parts: an anterior thin, parabolic arc shaped element that separates the secondary subtemporal and the subtemporal fenestrae, followed by a dorsoventrally flattened portion that is directed inside the sub temporal fenestrae.”

Actually there is no lateral process of the pterygoid divided in two parts. The anterior part is the ectopterygoid often fused to the palatine (= ectopalatine) in most, but not all pterosaurs (Fig. 1; exception: the dorygnathid specimen in Osi et al. remained unfused). The posterior portion is a new outgrowth of the pterygoid. Such a lateral ‘split’ is also found in Pteranodon (Fig. 2) and related sharp-rostrum pterosaur taxa.

From the Chen et al. abstract:
“Among all pterosaurs where the palate is known, the posterior configuration of the palate of D. weii is similar to some azhdarchoids, which is consistent with the suggested phylogenetic position of the Dsungaripteridae as closely related to the Azhdarchoidea.”

Actually dsungaripterids nest between germanodactylids and tapejarids (Fig. 2) in the large pterosaur tree (LPT), far from azhdarchids. A traditional error here perpetuated by taxon exclusion nests azhdarchids with tapejarids in the invalid clade (as currently defined) Azhdarchoidea. When more taxa are included in analysis, azhdarchids arise from tiny dorygnathids.

Tapejaridae and Pteranodontidae, both evolving from Germananodactylus.

Figure 3. The palates of several Tapejaridae and Pteranodontidae, both evolving from Germananodactylus. Note the yellow tooth at the tip of each sharp premaxilla here.

From the Chen et al. abstract:
“Furthermore, we identify symmetrical grooves on the lateral surface of the upper and lower jaws, that likely represent the impression of the edge of a keratinous sheath that would cover the upturned toothless rostrum during foraging activity, most likely consisting of hard elements, as has been previously assumed.”

Actually those ‘toothless’ jaws are tipped with large, procumbent single teeth. Check them for dentine and enamel. That’s what makes the tips of the jaws so sharp and resistant to abrasion (more resistant than bone), evident on older specimens (Fig. 4) with blunt tooth tips. Sometimes these teeth fall out. These teeth have roots. And they have a phylogenetic history traceable back to germanodactylids and earlier scaphognathids.

Figure 3. Dsungaripterus single teeth at the tips of the jaws. Phylogenetically these began with Germanodactylus (Fig. 4).

Figure 4. Dsungaripterus single teeth at the tips of the jaws. Phylogenetically these began with Germanodactylus (Fig. 4). The groove (gr) is the premaxilla-maxilla suture.

PS
That ‘groove’ (gr) in figure 4 is the premaxilla-maxilla suture, as noted by Young 1964 and Chen et al. 2020. In such cases, it is a better practice to label a suture as a suture, not a groove.

It’s always good to see new specimens,
but the presentation must be up-to-date. Too many pterosaur workers are perpetuating old myths. Color your bones and expand your taxon list. That will clarify most issues.


References
Bennett SC 1991. Morphology of the Late Cretaceous Pterosaur Pteranodonand Systematics of the Pterodactyloidea. [Volumes I and II]. – Ph.D. thesis, University of Kansas [Published by University Microfilms International/ProQuest].
Bennett SC 2001a, b. The osteology and functional morphology of the Late Cretaceous pterosaur Pteranodon. Part I and 2. General description of osteology. – Palaeontographica, Abteilung A, 260: 1-153.
Chen et al. (7 co-authors) 2020. New anatomical information on Dsungaripterus weii Young, 1964 with focus on the palatal region. PeerJ 8:e8741 DOI 10.7717/peerj.8741
Newton ET 1888. On the skull, brain and auditory organ of a new species of pterosaurian (Scaphognathus Purdoni) from the Upper Lias near Whitby, Yorkshire. Philosphoical Transaction of the Royal Society, London 179: 503-537.
Osi A, Prondvai E, Frey E and Pohl B 2010. New Interpretation of the Palate of Pterosaurs. The Anatomical Record 293: 243-258.
Peters D 2000. A Redescription of Four Prolacertiform Genera and Implications for Pterosaur Phylogenesis. Rivista Italiana di Paleontologia e Stratigrafia 106 (3): 293–336.
Seeley HG 1901. Dragons of the air. An account of extinct flying reptiles. – London, Methuen: 1-240.
Wellnhofer P 1978. Pterosauria. Handbuch der Paläoherpetologie, Teil 19.– Stuttgart, Gustav Fischer Verlag: 1-82.
Wellnhofer P 1991. The Illustrated Encyclopedia of Pterosaurs. London, Salamander Books, Limited: 1-192.
Williston SW 1902. On the skull of Nyctodactylus, an Upper Cretaceous pterodactyl. Journal of Geology 10:520–531.
Woodward AS 1902. On two skulls of Ornithosaurian Rhamphorhynchus. Annals of the Magazine Natural History 9:1.
Young CC 1964. On a new pterosaurian from Sinkiang, China. Vertebrata PalAsiatica 8: 221-256.

wiki/Dsungaripterus

https://pterosaurheresies.wordpress.com/2012/03/10/the-evolution-of-the-pterosaur-palate-part-1/

New pterosaur: Keresdrakon. Old cladogram.

Kellner et al. 2019
bring us a new desert pterosaur, Keresdrakon (Fig. 1). The bone is exceptionally preserved, similar to red bed Gobi Desert specimens from the Late Cretaceous. The exact age of the strata is “controversial.”  Kellner et al. nest their new specimen between Dsungaripteridae + Shenzhoupterus and Tapejaridae (omitting the unrelated Chaoyangopteridae + Azhdarchidae, see below).

From the abstract:
“Here we present a new tapejaromorph flying reptile from this site, Keresdrakon vilsoni gen. et sp. nov., which shows a unique blunt ridge on the dorsal surface of the posterior end of the dentary. Morphological and osteohistological features indicate that all recovered individuals represent late juveniles or sub-adults. This site shows the first direct evidence of sympatry in Pterosauria. The two distinct flying reptiles coexisted with a theropod dinosaur, providing a rare glimpse of a paleobiological community from a Cretaceous desert.”

Sympatry: “Occupying the same or overlapping geographic areas.” I have used the term ‘coeval’ to represent taxa from a similar formation (location and strata).

The same desert strata ‘cemetary of pterosaurs’
produced many partial specimens and several ontogenetic ages of the tapejarid, Caiuajara, which we looked at earlier here.

Figure 1. The larger bits and pieces of Keresdrakon. The bone is like bone, clearly distinct from the matrix.

Figure 1. The larger bits and pieces of Keresdrakon. The bone is like bone, clearly distinct from the desert matrix.

Unfortunately
Kellner et al. have excluded so many pterosaur taxa from their cladogram that it does not recover the four origins of pterodactyloid-grade pterosaurs known for the last 12 years (Peters 2007) and documented online in the large pterosaur tree (LPT, 239 taxa). Instead the authors follow the traditional, invalidated hypothesis that includes a monophyletic and awkward ‘Pterodactyloidea.’ that is only recovered by taxon exclusion.

Remember, 
dsungaripterids, tapejarids and pteranodontids all arise from various germanodactylids, which arise from pterodactylids, which arise from a branch of tiny scaphognathids. Ornithocheirds + cycnorhamphids arise from other tiny scaphognathids. Ctenochasmatids arise from one branch of dorygnathids. Azhdarchids arise from yet another branch of dorygnathids. All had tiny transitional pterosaur ancestors. Sadly, this is completely lost on the Kellner team, who have chosen to omit pertinent taxa from their analyses.

Otherwise
their topology is similar enough to the LPT. I have not yet entered Keresdrakon into the LRT. If the nesting differs from that of Kellner et al. (above), I will post that.


References
Kellner AWA, Weinschuütz LC, Holgado B, Bantim RAM and Sayão JM  2019. A new toothless pterosaur (Pterodactyloidea) from Southern Brazil with insights into the paleoecology of a Cretaceous desert. Anais da Academia Brasileira de Ciências (2019) 91(Suppl. 2): e20190768 (Annals of the Brazilian Academy of Sciences).
Peters D 2007. The origin and radiation of the Pterosauria. In D. Hone ed. Flugsaurier. The Wellnhofer pterosaur meeting, 2007, Munich, Germany. p. 27.

Mistralazhdarcho: a new pterosaur, but not an azhdarchid

Vullo et al. 2018 bring us a new small ‘azhdarchid’
known from a few 3D bones. In the large pterosaur tree (LPT, 236 taxa) Mistralazhdarcho nests with tiny Nemicolopterus and mid-sized Shenzhoupterus (Fig. 1). Mistralazhdarcho is more than twice as tall as Shenzhoupterus with similar gracile cervicals, a longer radius and shorter metacarpus. Distinct from Shenzhoupterus, the mandible is gracile, more like that of Nemicolopterus.

Figure 1. Mistralazhdarcho compared to reconstructions of Shenzhoupterus and Nemicolopterus.

Figure 1. Mistralazhdarcho compared to reconstructions of Shenzhoupterus and Nemicolopterus. A longer antebrachium is found in Mistalazdarcho.

A downturned dentary
is a trait found in this clade of pterosaurs, and to a lesser extent in sister sinopterids.

The small prominence at the ‘bend’ of the mandible
in Mistralazhdarcho is a curious trait not visible in Shenzhoupterus due to closed jaws in situ. Nemicolopterus might preserve that trait, but a humerus is under the mandible exactly at that point, making it difficult to determine in photos.

A warped deltopectoral crest,
like the one found in Mistalazdarcho (Fig. 1), is not found in azhdarchids. And look at the size range in this clade!

Having reconstructions for direct comparisons,
and a large cladogram that is regularly adding new taxa are tools the LPT and www.ReptileEvolution.com offer freely online to paleontologists worldwide. Best to test here rather than trust your hunch elsewhere.

References
Vullo R, Garcia G, Godefroit P, Cincotta A, and Valentin X 2018. Mistralazhdarcho maggii, gen. et sp. nov., a new azhdarchid pterosaur from the Upper Cretaceous of southeastern France. Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2018.1502670.

Banguela: a new pterosaur by a first-time author

Congratulations to Jaime Headden, who, along with Hebert Campos, had their discovery of Banguela oberlii, a toothless dsungaripterid NMSG SAO 251093, published. It’s a big jaw tip, producing an estimated skull length of 2 feet (60cm). That’s a bit more than a 50cm Dsungaripterus skull. Missing here is the jaw tip, which we learned earlier is a single tooth.

Figure 1. Banguela from several angles. Note the lack of teeth on this dsungaripterid.

Figure 1. Banguela from several angles. Note the lack of teeth on this dsungaripterid.

 

The Brazilian nickname ‘Banguela’ is commonly given to toothless people (Fig. 2), even though most retain a few teeth.

Figure 2. The original meaning of "Banguela", or what you'll find if you don't add the word "pterosaur" to your Google search.

Figure 2. The original meaning of “Banguela”, or what you’ll find if you don’t add the word “pterosaur” to your Google search.

JH mentioned, “An interesting rule of biology says when animals lose a feature, it cannot be regained. This is called Dollo’s Law, and it tells us about why birds don’t regrow teeth.”

Dollo’s Law needs to be brought up more often, like when pterosaurs are supposed to grow gigantic wing (4th) fingers from the vestiges most archosaurs have. Better to look for those sorts of fingers where they actually are, in the Lepidosauria.

JH reported, “Banguela oberlii is here hypothesized to be a derived dsungaripterid, though in our phylogenetic analysis (Headden & Campos, 2014) the new taxon was placed basal to other dsungaripterids. Further analysis supports a deeper nesting, but this work was not prepared at the time of publication.”

The large pterosaur tree nested dsungaripterids between toothy basal germanodactylids and toothless shenzoupterids and tapejarids, which is probably why Banguela initially nested basal, closer to other toothless clades.We also learned that basal taxa in virtually all pterosaur clades were tiny. So it is a good bet that big Banguela was a terminal, rather than a basal, taxon. There was a trend toward tooth loss in this clade of germanodactylia. Not surprising, but still wonderful, to see a “toothless” dsungaripterid. Any X-rays of those jaws planned?

References
Headden JA and Campos HBN 2014. An unusual edentulous pterosaur from the Early Cretaceous Romualdo Formation of Brazil. Historical Biology [Published online ahead of print]: 1-13. doi: 10.1080/08912963.2014.904302

More info online here at J. Headden’s blogpost.

 

 

 

 

Over the elbow or under? Pterosaur wing folding problem solved.

Finally a pterosaur that preserves the wing finger over the elbow solves the minor problem of wing folding.

Figure 1. Finally a pterosaur that preserves the wing finger over the elbow solves the minor problem of wing folding. This is hard evidence that means, over time, I’m going to have change a few reconstructions. Also note the robust ribs and wide scapulae here. The coracoid was not fused to it. Elbows are back, not out. There’s also a notarium you can see.

Pterosaurs folded their wings so tightly that the membrane virtually disappeared between a parallel antebrachium and wing finger (unlike the widely disseminated traditional view that keeps the wing finger open to handle the false deep chord wing membrane construction). The only question has been, does the wing finger fold medial (inside) to the elbow or lateral (outside) to the elbow? Having built several model skeletons, I thought the inside offered better protection and didn’t violate any rules.

Now we have a specimen attributed to Noripterus GIN125/1010 (Lü et al. 2009) that preserves this configuration lateral (outside, dorsal) to the elbow. The specimen is quite a bit smaller than the Noripterus holotype. Distinctively the metacarpus is shorter with regard to the tibia on GIN specimen, so the two are probably not conspecific (or congeneric, depending if you’re a splitter or a lumper). The GIN specimen is closer to Germanodactylus.

This is also the first specimen of a dsungaripterid I’ve seen that preserves the scapula, which appears to NOT fuse to the coracoid, similar to what we see in Shenzhoupterus, Noripterus and basal tapejarids. On the other hand, the more primitive Germanodactylus has a fused scapulocoracoid. So, fancy that, the smaller taxon has a fused s/c and the larger ones don’t (until we come to the larger tapejarids).

The new Noripterus to scale with Germanodactylus cristatus (left) and a chimaera of Phobetor and the holotype of Noripterus (right).

Figure 1. The new Noripterus to scale with Germanodactylus cristatus (left) and a chimaera of Phobetor and the holotype of Noripterus (right). Long-legged bastards, aren’t they? Here you can also see proportional differences between the holotype Noripterus (on the right) and the attributed specimen (in the middle). 

References
Lü J, Azuma Y, Dong Z, Barsbold R, Kobayashi Y and Lee Y-N 2009. New material of dsungaripterid pterosaurs (Pterosauria: Pterodactyloidea) from western Mongolia and its palaeoecological implications. Geological Magazine, 146(5): 690-700.