A Brazilian stem pteranodontid, and Brazil wants its fossils back!

Figure 1. The cf.Tupuxuara specimen is larger than sister taxa in the LPT.

Figure 1. The cf.Tupuxuara specimen is larger than sister taxa in the LPT.

cf.Tupuxuara (SMNK??? Elgin 2014, Early Cretaceous). Originally considered close to Tupuxuara, here this specimen nests between Eopteranodon and the base of the Pteranodontia. The metacarpals and antebrachium are relatively short. The large pentagonal sternal complex anchors large flight muscles. Distinct from the Pteranodontia, but like the Eopteranodon clade, the carpal and tarsal elements were not co-ossified. The ventral pelvis remained open, as in Eopteranodon and most tested nyctosaurids. In other words, this is NOT a female…necessarily.

Figure 2. Early Cretaceous cf.Tupuxuara from the Elgin 1914 dissertation. This taxon nests between the Solnhofen specimen B St 1878 VI 1 and Eopteranodontia + Pteranodontia in the LPT, far from Tupuxuara. Reconstruction from underlying in situ specimen from the Elgin 2014 dissertation available online.

Figure 2. Early Cretaceous cf.Tupuxuara from the Elgin 1914 dissertation. This taxon nests between the Solnhofen specimen B St 1878 VI 1 and Eopteranodontia + Pteranodontia in the LPT, far from Tupuxuara. Reconstruction from underlying in situ specimen from the Elgin 2014 dissertation available online. Missing parts filled in.

You might want to think of this pterosaur
as the first of the large Pteranodontia, still nesting with the Germanodactylus clade not leading to dsungaripterids, Shenzhoupterus and tapejarids, including Tupuxuara). Elanodactylus is another large member of this clade (Fig. 3).

Figure 3. Subset of the large pterosaur tree (LPT) with the addition of cf. Tupuxuara apart from Tupuxuara and at the base of the Pteranodontia.

Figure 3. Subset of the large pterosaur tree (LPT) with the addition of cf. Tupuxuara apart from Tupuxuara and at the base of the Pteranodontia.

The Elgin 2014 thesis was completed in May 2014.
Just a few months earlier, in March 2014 a paper appeared in Nature entitled, “Brazil clamps down on illegal fossil trade.” The first sentence reads, “Thirteen people are scheduled to go on trial in Brazil for smuggling fossils out of the country, apparently to private collectors and to museums in Germany and the United Kingdom.” Do you think Dr. Elgin was worried? Evidently not. In his PhD thesis Elgin wrote, The large numbers of [Chapada do Araripe] specimens that at the time of writing lacked any full or proper description was one of the major influences in the creation of this body of work, creating a catalogue of fossils that increase our understanding of this enigmatic group and permitting ready access to photographs and descriptions for future workers.” And for making those images available, Dr. Elgin, thank you!

Dr. Elgin further notes
“Brazil has banned the commercial sale of all fossil originating from its territories since 1942.” Then concludes, “The pterosaurs described within this body of work are presented for the good of the scientific community. While discouraging illicit trafficking is to be encouraged, the fact that the featured specimens are interred within a registered museum, rather than ending up within a private institution as would have certainly been their fate otherwise, guarantees the continued and universal access to any and all persons, to the benefit of the international community.”

Worried about the loss of Brazilian fossils to German museums,
Brazilian paleontologist, Alexander Kellner, cites the loss of cultural heritage. On the other hand, English paleontologist, David Martill quips, Knowing “dodgy” people is the only way to get samples, because the DNPM ignores requests to dig.” Brazilian paleontologist, Max Langer says, “Fossils must be kept in the country to help to improve Brazilian science.” And he expects fellow researchers to hold Brazil’s laws in higher regard than the private collectors who also fuel the trade.

David Martill expressed more of his thinking
in this online report, “In an email interview, Martill said that he “doesn’t care a damn how the fossil came from Brazil”, because that is “irrelevant to the scientific significance of the fossil. I am critical of all laws that interfere with the science of paleontology; and blanket bans on fossil collecting are indiscriminatory and only hinder science, No countries existed when the animals were fossilized.”

Bottom line:
Firsthand access to fossils… can sometimes get you into trouble with Brazil. You can see how the side line up here, with Brazilians hoping to stop exports and Europeans hoping to continue exports.

More tomorrow
on the Elgin dissertation…

References
Elgin RA 2014. Palaeobiology, Morphology, and Flight Characteristics of Pterodactyloid Pterosaurs. Innaugural Dissertation. Zur Erlangung der Doktorwürde Fakultät für Chemie und Geowissenschaften Institut für Geowissenschaften Ruprecht-Karls-Universität Heidelberg. Available online here.

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New flightless and giant nyctosaurs: Alcione and Barbaridactylus

Scale bar problems
and a lack of reconstructions in the original paper are issues here.

Longrich, Martill and Andres 2018
bring us news of “a diverse pterosaur assemblage from the late Maastrichtian of Morocco that includes not only Azhdarchidae but the youngest known Pteranodontidae and Nyctosauridae. [This] dramatically increases the diversity of Maastrichtian pterosaurs. At least 3 families —Pteranodontidae, Nyctosauridae, and Azhdarchidae — persisted into the late Maastrichtian. These patterns suggest an abrupt mass extinction of pterosaurs at the K-Pg boundary.”

The authors summary starts off with an invalid statement:
“Pterosaurs were winged cousins of the dinosaurs.”  That was invalidated by Peters 2000, 2007 and ignored every since. We looked at that problem earlier here, here and here in a 3-part series testing all candidates. It’s time to realize that no one will ever find pterosaur kin among the dinos. They’ve already been clearly identified among the lepidosaurs.

The authors failed to include the Maastrictian tupuxuarid
found in southern Texas (Fig. 1; TMM 42489-2) and did not consider the Maastrichtian footprints discovered in 1954 and reexamined in 2018 that include two ctenochasmatids we will look at tomorrow.

TMM 42489-2, the tall crested Latest Cretaceous large rostrum and mandible. It's a close match to that of Tupuxuara, otherwise known only from Early Cretaceous South American strata.

Figure 1. TMM 42489-2, the tall crested Latest Cretaceous large rostrum and mandible. It’s a close match to that of Tupuxuara, otherwise known only from Early Cretaceous South American strata.

Alcione elainus gen. et sp. nov.
The new 1.5x larger nyctosaurid, Alcione elainus, known from disassociated bones including a shorter radius + ulna, a shorter metacarpal 4, a larger femur, and a tiny sternal complex (identified as a ‘sternum’ in the text) only 40 percent the size of a standard nyctosaur sternal complex (if the scale bars are correct). When placed on a reconstruction of a more complete Nyctosaurus (UNSM 93000; Fig. 2), scaled to the humerus, the result produces a likely flightless nyctosaur. Strangely, the authors called this a “small nyctosaur” even though it is half again larger than UNSM 93000. The authors mislabeled the shorter, straighter scapula as a coracoid, and vice versa.

Figure 2. GIF movie of Nyctosaurus and Alcione showing a likely flightless nyctosaur based on the parts preserved.

Figure 2. GIF movie of Nyctosaurus and Alcione showing a likely flightless nyctosaur based on the parts preserved. Three frames change every 5 seconds. The sternum is tiny (assuming the scale bars are correct), the metacarpus and antebrachium are short and the femur is long.

They did not mention the possibility of flightlessness.
They did report, “The abbreviated distal wing elements in Alcione indicate a specialized flight style. The short, robust proportions suggest reduced wingspan and increased wing loading, implying distinct flight mechanics and an ecological shift. Short wings would increase lift-induced drag at low speeds, but reduced wing areas would decrease parasite drag at high speeds, suggesting that Alcione may have been adapted for relatively fast flapping flight compared to other nyctosaurids. Alternatively, reductions in wingspan might represent an adaptation to underwater feeding, i.e., plunge diving of the sort practiced by gannets, tropicbirds, and kingfishers, where smaller wings would reduce drag underwater.”

Not sure why they mentioned
‘distal wing elements’ here. They did not list or discuss distal wing elements elsewhere. Perhaps they meant proximal.

The reconstructed mandible of Alcione
is narrower than the rostrum in UNSM 93000.

Based on the vestigial fingers of UNSM 93000
and the short metacarpus of the new specimen, Alcione might have been the first pterosaur to walk on metacarpal 4, albeit at the very end of the reign of pterosaurs.

Other flightless pterosaurs include:
the basal azhdarchid form the Solnhofen, Jme-Sos 2428 and the Late Jurassic anurognathid PIN 2585/4 from the Sordes slab. They demonstrate that the distal wing elements reduce first. Thus the reconstruction, based on nyctosaur patterns restores a wing that was not volant.

Longrich, Martill and Andres did find a giant nyctosaur
which they named Barbaridactylus grandis based on a large humerus (Fig. 3). The humerus of the more complete UNSM 93000 specimen is 9.5 cm. By comparison the humerus in Barbaridactylus is 22.5 cm. I’m going to trust the text comment that the ulna + radius are 1.3x longer than the humerus. The scale bars indicate about half that length. Similar problem possible in the scapula/coracoid, according to the nyctosaur bauplan.

Figure 3. Barbaridactylus, a giant nyctosaurid. If the wing was like UNSM 93000, then it could fly. If the wing was like Alcione, then it could not. The scale bars did not match the text description on the ulna + radius, so both sizes are shown.

Figure 3. Barbaridactylus, a giant nyctosaurid. If the wing was like UNSM 93000, then it could fly. If the wing was like Alcione, then it could not. The scale bars did not match the text description on the ulna + radius, so both sizes are shown. Sometimes you have to be prepared for the occasional mistake in a published paper.

Other giant nyctosaurs
Earlier and here we noted giant nyctosaurs were flying over the Niobrara Sea (midwest North America) based on a large wing finger with unfused extensor tendon process (YPM 2501) and a large nyctosaur pelvis (KUVP 993; misinterpreted by Bennett (1991, 1992) as belonging to a female Pteranodon). 

No reconstructions were provided
by Longrich, Martill and Andres 2018. Reconstructions and a nyctosaur blueprint might have helped these paleontologists with firsthand access to the specimens discover the issues they missed.

It’s good to know
more pterosaurs made it to the latest Cretaceous.

References
Bennett SC 1991. Morphology of the Late Cretaceous Pterosaur Pteranodon and Systematics of the Pterodactyloidea. [Volumes I & II]. Ph.D. thesis, University of Kansas, University Microfilms International/ProQuest.
Bennett SC 1992.
 Sexual dimorphism of Pteranodon and other pterosaurs, with comments on cranial crests. Journal of Vertebrate Paleontology 12: 422–434.
Longrich NR, Martill DM, Andres B 2018.
Late Maastrichtian pterosaurs from North Africa and mass extinction of Pterosauria at the Cretaceous-Paleogene boundary. PLoS Biol 16(3): e2001663. https://doi.org/10.1371/journal.pbio.2001663
Peters D 2000b. A Redescription of Four Prolacertiform Genera and Implications for Pterosaur Phylogenesis. Rivista Italiana di Paleontologia e Stratigrafia 106 (3): 293–336.
Peters D 2007. 
The origin and radiation of the Pterosauria. In D. Hone ed. Flugsaurier. The Wellnhofer pterosaur meeting, 2007, Munich, Germany. p. 27.

Press coverage
Smithsonian
Newswise
PhysOrg

Smallest Pteranodon: Bennett 2017

Figure 1. The new small Pteranodon wing, FHSM 17956, compared to Ptweety and the adult NMC41-358 specimen.

Figure 1. The new small Pteranodon wing, FHSM 17956, compared to Ptweety and the adult NMC41-358 specimen. At half the size of the adult, the FHSM specimen would have been 4x the size of a hatchling.

A new small partial wing specimen of Pteranodon
discovered by Glen Rockers, was described by Bennett 2017 (Figs. 1-4). It is virtually identical to similar bones in Ptweety (Fig. 1), a specimen now lost to science and half the size of the Triebold specimen NMC41-358, which is similarly gracile. Click here to see more robust Pteranodon adults compared to the new small FHSM specimen.

Figure 2. FHSM 17956 compared to Ptweety. They are virtually identical, though Ptweety looks like a juvenile of a more robust variety of Pteranodon, thus a younger specimen because adults would be larger.

Figure 2. FHSM 17956 compared to Ptweety. They are virtually identical, though Ptweety looks like a juvenile of a more robust variety of Pteranodon, thus a younger specimen because adults would be larger.

Young (small) Pteranodon specimens
were essentially unknown prior to the Bennett paper. So this is important news.

Figure 2. Small Pteranodon, FHSM 17956, carpus insitu and reconstructed. Here several bones were reidentified.

Figure 3. Small Pteranodon, FHSM 17956, carpus insitu and reconstructed. Here several bones were reidentified. See reconstruction in figure 3. It demonstrates that all the newly identified parts fit together.

Unfortunately
a reconstruction based on Digital Graphic Segregation (DGS, Fig. 4) shows that Bennett, widely known as THE expert on Pteranodon going back to his PhD thesis, misidentified several carpal bones here. In his defense, that was easy to do. The distal carpal is beneath the other carpal bones and it has splinters that extend beyond it. Rather than using DGS, Bennett chose to outline bones the old fashioned way. This leads to problems that can be solved when you color each bone and bone splinter THEN test your colors with a reconstruction. Bennett provided no reconstruction that tested his outline tracings. Bennett also overlooked manual digit 5. The fragment (FR) probably comes from the crushed and splintered distal carpal. Bennett reported, “All carpal elements are severely deformed by compression such that they preserve little of their original morphology…” That’s because he misidentified elements that are otherwise identical to those of adult specimens.

Figure 3. Small Pteranodon (FHSM 17956) carpus reconstructed after several bones were reidentified.

Figure 4. Small Pteranodon (FHSM 17956) carpus reconstructed after several bones were reidentified.

 

Bennett also upholds several invalid paradigms

  1. Other small, short crested Pteranodon specimens represent young ones. Actually they represent taxa closer to the outgroup, Germanodacytylus
  2. Short-crested specimens are females. No male/female pairs have ever been documented. Rather short-crested taxa are closer to the crestless outgroup. 
  3. Large pelvis specimens  are females. No, they are large nyctosaurs. 
  4. Small size Rhamphorhynchus were juveniles of larger ones. No, phylogenetic analysis indicates a period of phylogenetic miniaturization followed the genesis of Rhamphorhynchus from larger Campylognathoides ancestors. Bone histology would include juvenile bone tissue in adults of these small, precocial and fast-breeding taxa. It is important that someday Bennett runs a phylogenetic analysis, something he told me decades ago was critical to understanding taxonomy. 
  5. There is no such thing as manual digit 5 in pterosaurs. He overlooked it here. 

Bennett now realizes:
“A new juvenile specimen of Pteranodon collected from the Smoky Hill Chalk Member is so small that it challenges the interpretation of rapid growth to large size before flying and feeding (Bennett, 2014a).” As everyone knows now, hatchling pterosaurs were able to fly shortly after hatching. To his credit, Bennett continues, “The interpretation of rapid growth while under parental care is rejected.”

Bennett examined the specimen under stereo microscope
and made mistakes here re-identified on a computer monitor applying colors to each bone to visually segregate one from another and facilitate accurate reconstruction. This is something that cannot take place using old-fashioned stereo microscopes.

Bennett occasionally
misidentifies small pterosaur bones. This was documented here dealing with the flat-headed anurognathid SMNS 81928, in which he considered the mandible a giant sclerotic ring in the front half the skull, different from all other pterosaurs. Bennett 2008 promoted an invalid hypothesis on the origin of the pterosaur wing based on imagination rather than taxa, documented here. Bennett’s (2007) interpretation of pteroid articulation against the preaxial carpal. was invalidated by Peters 2009 who nested it on the anterior radiale (Fig. 4).

Note
The extensor tendon process is articulated with the rest of m4.1, as in all Pteranodon specimens. Bennett once considered unfused  extensor tendon processes a sign of immaturity. This is not correct. As reported earlier, since pterosaurs are lepidosaurs they display lepidosaur fusion traits, typically not ontogenetic, but phylogenetic. As an example, in Nyctosaurus the extensor tendon process remains unfused, distinct from Pteranodon. Bennett insists that the extensor tendon process in the juvenile specimen is unfused but notes that the fragile cortical bone was lost during preparation. And just think about it.. the carpals, typically wrapped tightly in ligaments were scattered while the extensor tendon process didn’t move during taphonomy. By contrast, in Nyctosaurus the extensor tendon process popped off before the toes disarticulate.

Bennett avoid mentioning or citing
work by Peters 2009, which disputed Bennett 2007, who articulated the pteroid with the preaxial carpal. In order to do so, Bennett 2017 did not cite Bennett 2007, but did manage to cite nearly every other one of his papers. Kids.. sometimes you have to look for what’s not mentioned.

Pteranodon variety
is best seen and appreciated by direct comparison of the skulls and the post-crania. FHSM 17956 is a juvenile of a gracile form, similar to the Triebold specimen NMC41-358 (Fig. 1), a short-crested gracile variety. By contrast, Ptweety appears to be more similar to the more robust long-crested taxa. 

Bennett describes ontogenetic niches
for hatchling, juvenile and adult Pteranodon. This is necessary for 8x smaller hatchlings incapable of handling adult-sized prey.

In Bennett’s Acknowledgements he reports, 
“Constructive reviews from M. Witton and L. Codorniú led to improvements in the manuscript, and an anonymous reviewer disagreed with everything.” That anonymous reviewer was not me. That would be blackwashing. I always try to find something of value in any manuscript I review, even if I disagree with some of what is presented.

Bennett first described this taxon
in a 2014 SVP abstract. See how long traditional studies take to get published? I was just about to call Chris to see if he was okay. I’m glad to see he is still out there publishing important specimens.

References
Bennett SC 2007. Articulation and Function of the Pteroid Bone of Pterosaurs. Journal of Vertebrate Paleontology 27(4):881–891.
Bennett SC 2008. Morphological evolution of the forelimb of pterosaurs: myology and function. Pp. 127–141 in E Buffetaut and DWE Hone eds., Flugsaurier: pterosaur papers in honour of Peter Wellnhofer. Zitteliana, B28.
Bennett SC 2017. New smallest specimen of the pterosaur Pteranodon and ontogenetic niches in pterosaurs. Journal of Paleontology. pp.1-18. 0022-3360/15/0088-0906
doi: 10.1017/jpa.2017.84
Peters D 2009. A reinterpretation of pteroid articulation in pterosaurs. Journal of Vertebrate Paleontology 29:1327-1330.

There’s a Pteranodon wing at the University of Missouri

No doubt
it was reassembled into its present position, despite the in situ appearance.

Figure 1. There is just no way to avoid reflections on this stairwell specimen of Pteranodon, if you want to capture the whole specimen in one shot from a distance.

Figure 1. There is just no way to avoid reflections on this stairwell specimen of Pteranodon, if you want to capture the whole specimen in one shot from a distance.

Mizzou has very few other vertebrate fossils.
The University of Missouri (Mizzou) Geology Department has a wonderful and complete small ichthyosaur from the Holzmaden and they have a partial parasuchian skull from the Petrified Forest. I don’t think the Mizzou Pteranodon wing has a number. Small portions, like the wrist and free fingers are restored.

Figure 1. The Mizzou Pteranodon wing is average in size and not very robust or gracile compared to others shown here. Click to enlarge.

Figure 2. The Mizzou Pteranodon wing is average in size and not very robust or gracile compared to others shown here. Click to enlarge.

If we take the wing at face value
and place it in context with other Pteranodon wings (Fig. 2), we find that it is not the largest, nor the smallest, not the most robust, nor the most gracile. The scapulocoracoid is relatively small. This could be a chimaera.

And while we’re on the subject of variation,
it is worthwhile to consider the post-cranial variation in Pteranodon, a subject we touched on earlier here and in figure 2, but has not been adequately addressed elsewhere.  The lack of more than a few skulls matched to post-crania (Fig. 2) has hampered efforts, but a decent cladogram of Pteranodon interrelationships can still be managed.

Figure 2. The Tanking-Davis specimen compared to other forms. Specimen w and specimen z appear to be the closest to the Tanking-David specimen. Specimen 'w' = Pteranodon sternbergi? USNM 12167 (undescribed). Specimen 'z' = Pteranodon longiceps? Dawndraco? UALVP 24238. Click to enlarge.

Figure 2. The Tanking-Davis specimen compared to other forms. Specimen w and specimen z appear to be the closest to the Tanking-David specimen. Specimen ‘w’ = Pteranodon sternbergi? USNM 12167 (undescribed). Specimen ‘z’ = Pteranodon longiceps? Dawndraco? UALVP 24238. Click to enlarge.

Pushback on ‘Dawndraco’ (Pteranodon UALVP 24238)

Figure 1. Pteranoodn (Dawndraco) UALVP 24238 in situ, with Martin-Silverstone tracing applied, with mandible moved and missing parts colorized. The putative rostral tip looks more like displaced manus elements.

Figure 1. Pteranoodn (Dawndraco) UALVP 24238 in situ, with Martin-Silverstone tracing applied, with mandible moved and missing parts colorized. The putative rostral tip looks more like displaced manus elements. The crest and distal wing finger do not belong to the original specimen.

A new paper by Martin-Silverstone et al. 2017
disputes the earlier study by Kellner 2010, giving a new generic name to a well-preserved putative Pteranodon specimen, UALVP 24238, Figs. 1-3). They also write: “The re-evaluation of Pteranodon sensu lato by Kellner (2010) is troubling for pterosaur palaeontology, as so much of our understanding of pterosaur ontogeny and growth stem from Bennett’s work on Pteranodon and the conclusion that Pteranodon specimens can be divided into two closely and perhaps anagenetically related species.” Bennett’s conclusions were disputed earlier here, here and here, and are nowhere in evidence here (Fig. 2). Praise for Bennett’s work needs to be limited to those items that stand the tests of closer scrutiny and analysis, Gender and ontogenetic differences recovered in Bennett’s statistical analyses are not recovered in phylogenetic analysis.

Figure 2. The Tanking-Davis specimen compared to other forms. Specimen w and specimen z appear to be the closest to the Tanking-David specimen. Specimen 'w' = Pteranodon sternbergi? USNM 12167 (undescribed). Specimen 'z' = Pteranodon longiceps? Dawndraco? UALVP 24238. Click to enlarge.

Figure 2. The Tanking-Davis specimen compared to other forms. Specimen w and specimen z appear to be the closest to the Tanking-David specimen. Specimen ‘w’ = Pteranodon sternbergi? USNM 12167 (undescribed). Specimen ‘z’ = Pteranodon longiceps? Dawndraco? UALVP 24238. Click to enlarge.

As you can see (Fig. 2) NONE
of the known Pteranodon-grade skulls would be considered conspecific in the modern world, and few would be considered congeneric. Size and crest size differences are without a doubt phylogenetic (contra Bennett and Martin-Sivlerstone et al.) as demonstrated in the large pterosaur tree. You can’t get large or have a large crest without evolving from smaller progenitors. It may also be the case that Pteranodon, like pterosaurs in general were extremely individually variable within a genus, but we’d need a time machine or a mass fossil assemblage for that.

Moreover,
UALVP 24238 had a tiny cranium, very different from the large cranium of P. sternbergi (FHSM VP 339, Fig. 2).

Figure 3. The UALVP specimen of Pteranodon. Note the lack of taper in the rostrum along with the small size of the orbit.

Figure 3. The UALVP specimen of Pteranodon. Note the lack of taper in the rostrum along with the small size of the orbit.

From the Martin-Silverstone et al. 2017 abstract:
“The previous most comprehensive study on Pteranodon [Bennett 1991, 1992m 19994, 2001] recognized two species: P. longiceps and P. sternbergi, but complete skeletons of Pteranodon are rare. One of the best preserved (UALVP 24238) has been identified as both P. sternbergi and as a new genus and species, Dawndraco kanzai. Here, the specimen is redescribed, additional portions of the rostrum are identified for the first time, new details of the specimen’s provenance and preparation history are presented, and its taxonomic placement is discussed. Whereas the shape of the rostrum appears at first glance to distinguish it from known Pteranodon, this feature is more parsimoniously interpreted in the context of sexual dimorphism; a male has a longer and therefore more shallowly tapering rostrum. Metrics from this specimen, and from published photographs and illustrations, support the conclusion that the rostrum of UALVP 24238 is not unique, and so provides no grounds for recognition of a taxon distinct from Pteranodon sternbergi. Other putatively unique features of UALVP 24238 are examined and found unconvincing.”

The rostrum is not the key trait that separates
UALVP 24238 from P. sternbergi (Fig. 2). It’s the cranium (among comparable elements preserved). The two species are related, but not conspecific. A phylogenetic analysis would have been helpful here. A set of skull reconstructions would have made things clear. Both are lacking from the new Martin-Silverstone study.

References
Bennett SC 1991. Morphology of the Late Cretaceous Pterosaur Pteranodon and Systematics of the Pterodactyloidea. [Volumes I & II]. Ph.D. thesis, University of Kansas, University Microfilms International/ProQuest.
Bennett SC 1992. Sexual dimorphism of Pteranodon and other pterosaurs, with comments on cranial crests. Journal of Vertebrate Paleontology 12: 422–434.
Bennett SC 1994. Taxonomy and systematics of the Late Cretaceous pterosaur Pteranodon (Pterosauria, Pterodactyloidea). Occassional Papers of the Natural History Museum University of Kansas 169: 1–70.
Bennett SC 2001. The osteology and functional morphology of the Late Cretaceous pterosaur Pteranodon. Part I. General description of osteology. Palaeontographica, Abteilung A, 260: 1–112. Part II. Functional morphology. Palaeontographica, Abteilung A, 260: 113–153.
Kellner AWA 2010. Comments on the Pteranodontidae (Pterosauria, Pterodactyloidea)
with the description of two new species. Anais da Academia Brasileira de Ciências 82(4): 1063-1084.
Martin-Silverstone E, Glaser JRN, Acorn JH, Mohr S and Currie PJ 2017. Reassesment of Dawndraco kanzai Kellner, 2010 and reassignment of the type specimen to Pteranodon sternbergi Harksen, 1966.  Vertebrate Anatomy Morphology Palaeontology 3:47-59.
Marsh OC 1876a. Notice of a new sub-order of Pterosauria. American Journal of Science, Series 3, 11:507-509.
Miller HW 1971. A skull of Pteranodon (Longicepia) longiceps Marsh associated with wing and body parts. Kansas Academy of Science, Transactions 74(10):20-33.

wiki/Pteranodon

New Perspectives on Pterosaur Palaeobiology volume

The 2015 pterosaur meeting in Portsmouth, England
brings us several new papers. The meeting and abstracts were previewed here and reported on here by a participant.

From the intro: “The field of pterosaur research in palaeontology continues its rapid growth and diversification that began in recent decades. This volume is a collection of papers on these extinct flying reptiles that includes work on their taxonomy, behaviour, ecology and relationships.”

Oddly, the number of abstracts far exceeded the very few papers this time.

Palmer 2017 wrote:
“The preservation of the wing membrane of pterosaurs is very poor and the available fossil evidence does not allow its properties to be reconstructed. In contrast, the fossil record for the wing bones is relatively good and the advent of CT scanning has made it possible to build high-fidelity structural models of the wing spar. The bending strength of the wing spar of a 6 m wingspan ornithocheirid pterosaur is used to infer the likely membrane tension. The tensions required to suppress aeroelastic flutter and to minimize ballooning of the membrane under flight loads are also estimated. All three estimates are of similar magnitude and imply that the membrane must have contained high-modulus material, supporting the view that the reinforcing aktinofibrils were keratinous.”

Contra Palmer’s unfounded assertion, there are several specimens of pterosaurs that provide an excellent view of the wing membrane. For the most part wing shape designs continue to be stuck in the Dark Ages among several pterosaur workers with some actually flipping the wing tips. Those problems need to improve before further work on pterosaur wings.

Dalla Vecchia 2017 wrote:
“An incomplete bone from the latest Cretaceous dinosaur site of Villaggio del Pescatore (Trieste Province, Italy) is definitely a wing metacarpal of a pterodactyloid pterosaur. It represents the only Italian Cretaceous pterosaur remains known, as well as the only pterosaur from the Adriatic Carbonate Platform. With an estimated minimum length of 136 mm, it belongs to a relatively small individual relative to the standard of latest Cretaceous pterodactyloids. It is not as elongated and gracile as azhdarchid wing metacarpals and shows a mix of features found in Pteranodon and some more basal pterodactyloids. It is one of the very few remains of putative non-azhdarchid pterosaurs from the upper Campanian–Maastrichtian worldwide and supports the view that the Azhdarchidae were not the only pterosaur clade existing during latest Cretaceous times.”

Always good to see the gamut of pterosaurs increase.

Witton 2017 wrote:
“Understanding the ecological roles of pterosaurs is a challenging pursuit, but one aided by a growing body of fossil evidence for their dietary preferences and roles as food sources for other species. Pterosaur foraging behaviour is represented by preserved gut content, stomach regurgitates, coprolites and feeding traces. Pterosaurs being eaten by other species are recorded by tooth marks and teeth embedded in their fossil bones, consumer gut content and regurgitate, and their preservation entangled with predatory animals. This palaeoecological record has improved in recent years, but remains highly selective. The Jurassic rhamphorhynchid Rhamphorhynchus, Cretaceous ornithocheiroid Pteranodon and azhdarchid pterosaurs currently have the most substantial palaeoecological records. The food species and consumers of these taxa conform to lifestyle predictions for these groups. Rhamphorhynchus and Pteranodon ate and were eaten by aquatic species, matching expectations of these animals as sea-going, perhaps partly aquatic species. Possible azhdarchid pterosaur foraging traces alongside pterosaur tracks, and evidence that these animals were eaten by dinosaurs and Crocodyliformes, are consistent with hypotheses that azhdarchids foraged and lived in terrestrial settings. Fossil evidence of pterosaur palaeoecology remains rare: researchers are strongly encouraged to put specimens showing details of dietary preferences, foraging strategies or interactions with other animals on record.”

When Pteranodon is no longer considered an ornithocheiroid by ptero workers, I will celebrate.

Bennett and Penkalski 2017 wrote:
“Four specimens of the pterosaur Pteranodon exhibit patterns of irregular alternating light and dark bands on the lateral surfaces of the upper jaw anterior to the nasoantorbital fenestra. Examinations reveal that the maxilla and premaxilla of Pteranodon consisted of two thin sheets of bone interconnected by regularly spaced septa with the spaces contained within presumably pneumatized, resulting in a structure analogous to modern honeycomb sandwich panels. The alternating light and dark bands resulted from waves of bone deposition moving anteriorly along the external surface of the lateral sheet of bone and laying down thin laminae of new bone while bone was simultaneously resorbed from the internal surface of the lateral sheet to maintain its thickness. The specimens that exhibit the bands were immature males and no banding was found in mature specimens or immature females. Therefore, the presence of the bands in immature males is interpreted as correlated with the enlargement and reshaping of the rostrum as males approached and attained sexual maturity.”

Wonder if those immature males were really just more primitive species with smaller size and smaller crest? Earlier Bennett erred by considering the morphological differences in various Pteranodon specimens ontogenetic, rather than phylogenetic. He failed to realize that Pteranodon specimens don’t get to giant size with giant crests without going through transitional mid-size specimens derived from certain small, crestless Germanodactylus specimens. The lamination of pterosaur skull bones is something first described here with the anterior extension of the jugal nearly to the tip of the rostrum. However, what these two workers are describing appears to be another thing entirely.

Martill and Moser 2017 wrote:
“Six specimens accessioned to the Bavarian State Collection for Palaeontology and Geology in Munich, Germany, in 1966 are identified as coming from a gigantic pterodactyloid pterosaur. The previously undescribed material was obtained in 1955 by Jean Otto Haas and compares favourably in size with the type specimen of the Late Cretaceous (Maastrichtian) azhdarchid pterosaur Arambourgiania philadelphiae (Arambourg 1959) from the same locality/region. The material represents fragments of two cervical vertebrae, a neural arch, a left femur, a ?radius, and a metacarpal IV and bones of problematic identity, and does not duplicate the type material of Arambourgiania. The timing of its collection and its locality of Ruseifa, Jordan suggest it might pertain to the same individual as the holotype.” 

Interesting. More parts for the same specimen? That’s like more pieces to the same puzzle. On the other hand, when the term ‘pterodactyloid’ pterosaur falls by the wayside, I will also celebrate. Azhdarchids are not closely related tp Pterodactylus.

Rigal et al. 2017 wrote:
“A specimen of a pterodactyloid pterosaur from the Upper Tunbridge Wells Sand Formation (Early Cretaceous, Valanginian) of Bexhill, East Sussex, southern England is described. It comprises a small fragment of jaw with teeth, a partial vertebral column and associated incomplete wing bones. The juxtaposition of the bones suggests that the specimen was originally more complete and articulated. Its precise phylogenetic relationships are uncertain but it represents an indeterminate lonchodectid with affinities to Lonchodectes sagittirostris (Owen 1874) which is reviewed here, and may belong in Lonchodraco Rodrigues & Kellner 2013. This specimen is only the third record of pterosaurs from this formation.”

England is famous for excellent preservation of pterosaur bits and pieces, mostly jaws, as is the case here. The specimen is named Serradraco and has been known for over 150 years.

Henderson 2017 wrote:
“Simple, three-dimensional, digital models of the crania and mandibles of 22 pterosaurs – 13 pterodactyloids and nine non-pterodactyloids (‘rhamphorhynchoids’) – were generated to investigate gross-level mechanical aspects of the skulls as they would related to feeding behaviour such as bite force and speed of jaw motions. The key parameter was the determination of second moments of area of the mid-muzzle region and the computation of the bending moment relative to the occiput. The shorter, stockier skulls of basal ‘rhamphorhynchoids’ were the strongest for their size in terms of potential resistance to dorso-ventral bending, and this finding correlates with their robust dentitions. More derived ‘rhamphorhynchoids’ showed the start of a trend towards weaker skulls, but faster jaw adduction was interpreted to be an adaptation for the snatching of small prey. Pterodactyloids continued the trend to lengthen the skull and to reduce its cross-sectional area, resulting in less stiff skulls, but more rapid opening and closing of the jaws. Changes in the rear of the skulls and the development of coronoid eminences on the mandibles of all the pterodactyloids are correlated with the reduction in bite force and a concomitant increase in jaw closing speed.”

This makes sense, though I worry that ‘simple digital models’ by Henderson have not fared well in the past.

Hone, Jiang and Xu 2017 wrote: 
“After being inaccessible for a number of years, the holotype and other specimens of the dsungaripterid pterodactyloid pterosaur Noripterus complicidens are again available for study. Numerous taxa assigned to the Dsungaripteridae have been described since the erection of Noripterus, but with limited comparisons to this genus. Based on the information from Young’s original material here we revise the taxonomic identity of N. complicidens and that of other Asian dsungaripterids. We conclude that N. complicidens is likely to be distinct from the material recovered from Mongolia and this latter material should be placed in a separate genus.”

Okay. Wonderful. Thought I think some of us knew that already based on photo data.

And speaking of southern England…
did the U. of Leicester clade ever find the grad student they advertised for to prove the pterosaur quad leap hypothesis?

References
2017. New Perspectives on Pterosaur Palaeobiology. Hone  DWE, Witton MP and Martill DM editors. Geological Society, London SP455.
Bennett SC and Penkalski P 2017. Waves of bone deposition on the rostrum of the pterosaur Pteranodon.
Dalla Vecchia FM 2017. A wing metacarpal from Italy and its implications for latest Cretaceous pterosaur diversity.
Henderson DM 2017. Using three-dimensional, digital models of pterosaur skulls for the investigation of their relative bite forces and feeding styles.
Hone DWE, Jiang S, and Xu X 2017. A taxonomic revision of Noripterus complicidens and Asian members of the Dsungaripteridae.
Martill DM and Moser M 2017. Topotype specimens probably attributable to the giant azhdarchid pterosaur Arambourgiania philadelphiae (Arambourg 1959).
Palmer C 2017. Inferring the properties of the pterosaur wing membrane.
Rigal S, Martill DM, and Sweetman SC 2017. A new pterosaur specimen from the Upper Tunbridge Wells Sand Formation (Cretaceous, Valanginian) of southern England and a review of Lonchodectes sagittirostris (Owen 1874).
Witton MP 2017. Pterosaurs in Mesozoic food webs: a review of fossil evidence.

 

Pterodactyls Alive! 1984 BBC video with David Attenborough on YouTube

Pterodactyls Alive! on YouTube click here

It’s more than 30 years old.
It’s not HD. It still supports the notion of a inverted hanging pterosaur. It precedes the discovery of eggs. Even so, it features a gliding Pteranodon model, lots of great sea bird scenes (including diving pelicans, soaring, dipping frigate birds and skimming skimmers) along with several great bat scenes (including grounded bats taking off).

And Mr. Attenborough was just starting to get gray hair back then.  :  )

The video also stars a bipedal animated Dimorphodon following the then recent release of Padian’s early work on that pterosaur.