Crayssac basal pterosaur tracks? …or tenrec tracks?

Earlier we looked at Mazin and Pouech 2020
who claimed they had discovered “the first non-pterodactyloid pterosaurian trackways.” At the time, only the abstract was available to discuss and criticize.

Nine years ago
Peters 2011 published anurognathid tracks, which makes them the first non-pterodactyloid pterosaurian trackways published. Notable by its exclusion, Mazin and Pouech 2020 did not cite, “A catalog of pterosaur pedes for trackmaker identification” (Peters 2011), confirming Dr. S. Christopher Bennett’s threat, You will not be published. And if you are published, you will not be cited.”

Now that I have seen the paper and the tracks,
(Figs. 1, 2) let’s determine what sort of tetrapod made those tracks named, Rhamphichnus crayssacensis, because they don’t look like other pterosaur tracks, as workers (see below) acknowledge.

Diagnosis from Mazin and Pouech 2020:
“Quadrupedal trackway with tridactyl digitigrade manus-prints and pentadactyl plantigrade to digitigrade pes-prints. Subparallel manus digit-prints orientated anteriorly. Pentadactyl pes-prints with more or less divergent digit prints. Pedal digit V divergent and postero-laterally rejected. Manus trackway slightly to clearly wider than the pes trackway.”

Distinct from typical pterosaur manus tracks:

  1. tridactyl digit prints are subparallel (rather than widely splayed)
  2. digits are oriented anteriorly (rather than laterally to posteriorly)
  3. digits sometimes include additional medial and lateral impressions (never seen in other pterosaur tracks)
  4. no claw marks are present (that seems wrong based on Fig. 1)
  5. the manus impression is just anterior to the pes impression (rather than laterally and posteriorly, as in other pterosaur tracks)

Figure 1. Images from Mazin and Pouech 2020. Some manus tracks have at least four digits.

Figure 1. Images from Mazin and Pouech 2020. Some manus tracks have at least four digits.

There are many
basal and derived pterosaurs with pedal digit 2 (or 2 and 3) the longest, distinct from Triassic pterosaurs. These were all examined and rejected as potential trackmakers matching Rhamphichnus for various reasons.

I also looked at 1600+ non-pterosaur trackmakers
due to the many unexpected traits (see list above) present in the Rhamphichnus tracks.

First and foremost,
the pterosaur antebrachium (radius + ulna) could not be pronated to produce anteriorly-oriented Rhamphichnus tracks. Due to folding and flying issues, pterosaurs, like birds, do not have the ability to pronate and supinate the wing. That’s why all pterosaur manus tracks are oriented laterally with fingers at full extension, impressing into the substrate. That manus digit 3 is often rotated posteriorly is a clue to its lepidosaurian ancestry. These facts form the hypothesis of a secondarily quadrupedal configuration for some, but not all pterosaurs.

One overlooked trackmaker stood out as a good match
for Rhamphichnus: the tenrec, Tenrec (Fig. 2), a small digitigrade quadrupedal mammal currently restricted to Madagascar. The medial and lateral manual digits are shorter than 2-4, which are parallel in orientation.

Figure 2. Rhamphichnus tracks compared to a Tenrec trackmaker.

Figure 2. Rhamphichnus tracks compared to a Tenrec trackmaker. The brevity of pedal digit 5 is a mismatch, but a related taxon, Leptictidium, likewise reduces pedal digit 5.

One of those Tenrec sisters,
Rhynchocyon, greatly reduces manual digits 1 and 5, but pedal digit 3 is the longest.

Another Tenrec sister,
Leptictidium (Fig. 3), has a pes with a reduced pedal digit 5, but a short digit 2, but the manus is also a good match for Rhamphichnus. So there is great variation in the pes of tenrec clade members. Still, a small tenrec-like mammal remains a more parsimonious trackmaker than any Late Jurassic pterosaur. They were able to pronate the manus!

Figure 2. Elements of Leptictidium from Storch and Lister 1985.

Figure 3. Elements of Leptictidium from Storch and Lister 1985.

Due to taxon exclusion,
Mazin and Pouech 2020 did not consider alternative trackmakers for the pterosaur-beach Rhamphichnus tracks that don’t match other pterosaur tracks or extremities. Now we’re stuck with an inappropriate name for these Late Jurassic tenrec tracks.

A late Jurassic tenrec?
The large reptile tree (LRT, 1637 taxa) supports the probability that a sister to Tenrec was present in in the Late Jurassic based on the coeval presence of derived members of Glires (Multiturberculata). Placental mammal fossils remain extremely rare in the Mesozoic, but these impressions add to their chronology.

It is worth repeating, due to the subject matter,
the Crayssac pterosaur beach still includes the pes of the JME-SOS 4009 specimen attributed to Rhamphorhynchus, as mentioned earlier. Here it is again (Fig. 4).

Pes of Rhamphorhynchus and matching track

Figure 4. Crayssac track different from all others. Inset: Pes of Rhamphorhynchus muensteri JME-SOS 4009, no. 62 in the Wellnhofer catalog

twitter.com/Mark Witton mistakenly reports:
“Turns out we’ve been over-thinking it (pedal digit 5): it just lays flat on the ground during walking, like a regular toe.”

“For one, the walking fingers face forward, not sideways, as in pterodactyloids. This seems weird, but it turns out that non-ptero wing fingers fold roughly perpendicular to the walking digits.”

These basic bungles by a PhD pterosaur worker
demonstrate the dominance of myth-making among purported experts due to accepting published results like a journalist, without testing them, like a scientist. Dr. Witton’s 2013 pterosaur book is full of similar mistakes reviewed here in a seven-part series.


References
Mazin J-M and Pouech J 2020.The first non-pterodactyloid pterosaurian trackways and the terrestrial ability of non-pterodactyloid pterosaurs. Geobios 16 January 2020. PDF
Peters, D. 2011. A Catalog of Pterosaur Pedes for Trackmaker Identification
Ichnos 18(2):114-141. http://dx.doi.org/10.1080/10420940.2011.573605

https://pterosaurheresies.wordpress.com/2020/01/18/first-non-pterodactyloid-pterosaurian-trackways-ever-described-no/

 

First non-pterodactyloid pterosaurian trackways ever described? …No

Updated April 18. 2020
The four-fingered manus tracks (identified below out of context as a rhamphorhynchid pes track) belong to a tenrec, not a pterosaur. Details here. 

Mazin and Pouech 2020
report on basal pterosaur tracks from the “Pterosaur Beach of Crayssac” (Upper Jurassic), which they consider novel.

From the abstract:
“New discoveries on the ichnological site known as “the Pterosaur Beach of Crayssac” (lower Tithonian, Upper Jurassic; south-western France) answer the question of terrestrial capabilities of non-pterodactyloid pterosaurs. If the terrestrial type of locomotion of pterodactyloid pterosaurs has been solved from ichnological evidence for more than twenty years, no tracks and trackways referable to non-pterodactyloid pterosaurs have ever been described.”

Not true. Peters 2011 included several anurognathid tracks and matched them to trackmakers (Fig. 1). We looked at the so-called ‘Sauria aberrante‘ from Patagonia earlier here in 2011.

Digitigrade pterosaur tracks

Figure 1. A pterosaur pes belonging to a large anurognathid, “Dimorphodon weintraubi,” alongside three digitigrade anurognathid tracks and a graphic representation of the phalanges within the Sauria aberrante track.in

Continuing from the abstract:
“Thus, the debate on terrestrial capabilities of these non-pterodactyloids was based on morpho-functional studies, with the main conclusion that those pterosaurs were arboreal dwellers and bad walkers.”

Not true. Peters 2000a, b, 2011, demonstrated a bipedal ability in pterosaurs superior to that of extant bipedal lizards, (e.g. Chlamydosaurus).

The ‘bad-walker myth’ results from mythology promoted by Unwin and Bakhurina1994 with regard to several misinterpretations of Sordes pilosus. including the invalid binding of the hind limbs with a uropatagium along with the invalid continuation of the brachiopatagium trailing edge to the ankle.

Dimorphodon pes with shadows.

Figure 2. Dimorphodon pes with shadows. Pedal digit 5 can swing beneath the metatarsus. Note elevated proximal phalanges.

“Six trackways referable to three non-pterodactyloid new ichnotaxa, maybe closely related to Rhamphorhynchidae, are described in this work. Their study leads to the conclusion that grounded non-pterodatyloids, at least during the Late Jurassic, were quadrupedal with digitigrade manus and plantigrade to digitigrade pes.”

This confirms work by Peters 2000a, b, 2011.

“They were clearly good walkers, even if hindlimbs are supposed to be hampered by the uropatagium, what could have constrained the terrestrial agility of these animals.”

A single binding uropatagium is a myth invalidated several years ago. See above.

“Thus, from ichnological evidence and contrary to the current hypotheses, non-pterodactyloid pterosaurs seem to have been good walkers even though their trackways are very rare or unidentified to date.”

This also confirms work by Peters 2000a, b, 2011.

Cosesaurus matched to Rotodactylus from Peters 2000.

Figuue 3.  Cosesaurus matched to Rotodactylus from Peters 2000.

Continuing from the abstract:
“This rarity could be due to behaviour rather than to functional capacities, many non-pterodactyloids being considered both littoral fishers and arboreal or cliff dwellers. However, the concept of non-pterodactyloid “good climbers and bad walkers” has to be modified to “good climbers and rare walkers”, unless many non-pterodactyloid ichnites have yet to be discovered.”

Many non-pterodactyloid ichnites have been discovered (Fig. 1). Unfortunately, they have been ignored and omitted by authors, including Mazin and Pouech. It’s never a good time to remember Dr. S. Christopher Bennett’s infamous threat, “You will not be published. And if you are published, you will not be cited.”

Pes of Rhamphorhynchus and matching track

Figure 4. Crayssac track different from all others. Inset: Pes of Rhamphorhynchus muensteri JME-SOS 4009, no. 62 in the Wellnhofer catalog. NOTE ADDED APRIL 18, 2020. The Martin-Silverstone paper (link above) identifies this as a manus track. It belongs to a tenrec, not a pterosaur. 

This used to be considered
crankery. Now they confirm the heretical hypotheses, but claim them as their own.

Unique among Rhamphorhynchus specimens, Rhamphorhynchus muensteri (Wellnhofer 1975) JME-SOS 4009, no. 62 in the Wellnhofer catalog has a long digit 4.

Figur 5. Unique among Rhamphorhynchus specimens, Rhamphorhynchus muensteri (Wellnhofer 1975) JME-SOS 4009, no. 62 in the Wellnhofer catalog has a long digit 4.

BTW
Earlier a published Craysaac a basal pterosaur track was matched to the pes of a particular Rhamphorhynchus (no. 62, JME-SOS-4009; Figs. 4, 5) in a 2011 blogpost on digitigrade pterosaur footprints. I heard of the Crayssac rhamph-tracks years ago and am glad to see their present publication. Still awaiting the paper. When it comes: more details.

NOTE ADDED APRIL 18, 2020. The Martin-Silverstone paper (link above) identifies this as a manus track. It belongs to a tenrec, not a pterosaur.

Cosesaurus and Rotodactylus, a perfect match.

Figure 6. Cosesaurus and Rotodactylus, a perfect match. Elevate the proximal phalanges along with the metatarsus, bend back digit 5 and Cosesaurus (left) fits perfectly into Rotodactylus (right).

We also have tracks made by pre-pterosaur fenestrasaurs.
Rotodactylus, UCB 38023, Moenkopi Formation (Peabody,1948; Peters, 2000a; Figs. 3, 6)


References
Casamiquela RM 1962. Sobre la pisada de un presunto sauria aberrante en el Liassico del Neuquen (Patagonia). Ameghiniana, 2(10): 183–186.
Mazin J-M and Pouech J 2020. The first non-pterodactyloid pterosaurian trackways and the terrestrial ability of non-pterodactyloid pterosaurs. Geobios 16 January 2020. PDF
Peabody FE 1948.Reptile and amphibian trackways from the Lower Triassic Moenkopi formation of Arizona and Utah.  University of California Publications, Bulletin of the  Department of Geological Sciences 27: 295-468.
Peters D 2000a. Description and Interpretation of Interphalangeal Lines in Tetrapods.  Ichnos 7:11-41.
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. 2011. A Catalog of Pterosaur Pedes for Trackmaker Identification
Ichnos 18(2):114-141. http://dx.doi.org/10.1080/10420940.2011.573605
Unwin DM and Bakhurina NN 1994. Sordes pilosus and the nature of the pterosaur flight apparatus. Nature 371: 62-64.

Sauria aberrante MLP 61-IX-4-1 (Casamiquela, 1962)
Track D, Sundance Formation (Harris and Lacovara, 2004)
Track C, Sundance Formation (Harris and Lacovara, 2004)

https://pterosaurheresies.wordpress.com/2012/03/02/the-case-against-bipedal-pterosaurs

https://pterosaurheresies.wordpress.com/2011/08/09/pterosaurs-bipedal-quadrupedal-or-both/

Upper Jurassic tidal flat pterosaur tracks from Poland

Note:
The following is from an unedited manuscript accepted for publication and pre-published online. The editors note: copyediting may change the contents by the time this is officially published. Not sure why the editors are going this route, except for comment and validation. Hope this gets back to them for the help it offers.

Elgh et al. 2019 report,
“In this paper, we report newly discovered, well-preserved pterosaur track material.”

The authors mistakenly report, 
“Intermediates between most of these states can be seen in the non-pterodactyloid
groups most closely related to the pterodactyloids, e.g. the rhamphorhynchids and wukongopterids” 

No, tiny dorygnathids and scaphognathids are transitional taxa when more taxa are added in the large pterosaur tree (LPT, 238 taxa). Wukongopterids are a sterile lineage, otherwise known as a dead end. There are 4 convergent pterodactyloid-grade clades. All these are recovered by adding taxa without bias.

The authors mistakenly report,
“As noted previously, digit V differs greatly between non-pterodactyloids and pterodactyloids. In non-pterodactyloids this digit is long and supported the uropatagium.”

No, the long and unique fifth digit is found in tanystropheids, langobardisaurids and fenestrasaurs like Cosesaurus and Sharovipteryx. No pterosaur fossil shows uropatagial support. This is a myth. Exceptionally, and for hind wing gliding, each uropatagium extends nearly to the tip of digit 5 in Sharovipteryx.

The authors mistakenly report, 
“Furthermore, pterodactyloids lost their teeth in several lineages, something not seen among nonpterodactyloids.” 

Adding taxa recovers four pterodactyloid-grade clades, as shown by LPT. Two arise from distinct lineages within Dorygnathus. Two others arise from tiny descendants of Scaphognathus. One clade from each lineage produces toothless taxa.

The authors mistakenly report,
“The non-wing bearing digits are much shorter and increase in length from IIII.” 

Typically, yes, but not always. Sometimes all three small phalanges are sub-equal in length.

The authors mistakenly report, 
“Their phalangeal formula is 2-3-4-4, since the wing finger ungual is lost.”

Not true. I have shown many examples of a wing ungual.

The authors mistakenly report, 
“The pes has five digits with a phalangeal formula of 2-3-4-5-2. The penultimate phalanx is elongated in digits I-IV.”

Not true. Pterodaustro (Fig. 1) and several other beach coming pterosaurs do not have elongate penultimate pedal phalanges. The authors cite the invalidated paper by Unwin 1996, rather than Peters 2011, which compared and showed many examples of pterosaur feet and tracks.

Figure 1. A selection of ctenochasmatid feet. Note the short penultimate phalanges (green).

Figure 1. A selection of ctenochasmatid feet from Peters 2011. Note the short penultimate phalanges (green) are not longer than the longest phalanx in series.

The authors mistakenly report,
“The wukongopterids, being the non-pterodactyloid group(s) most closely related to the pterodactyloids have, as with many characters, an intermediate state with a fifth digit that is shorter than in other non-pterodactyloids but longer than in pterodactyloids.”

Not true. Wukongopterids generally have a larger pedal digit 5 than in many other basal pterosaurs and are not related to derived pterosaurs despite several traits that converge. As mentioned above, phylogenetic miniaturization occurred 4 times in the ancestry of the 4 pterodactyloid-grade pterosaurs.

The authors mistakenly report, 
“It is unclear how the fifth digit functioned in terrestrial locomotion in all groups of pterosaurs.” 

Not true. Peters 2000 and 2011 showed exactly how pedal digit 5 was used with comparable tracks and hypothetical perching situations.

To eliminate considering the above issues, the authors report,
“no exhaustive morphometrical methods compare pes and manus impressions with anatomical details to pes and manus body fossils have been made. The most creative attempt to match pes anatomy to tracks by Peters (2011) regrettably introduces too many speculations to be of use in this study.”

That’s how it works, folks. Like Hone and Benton, 2007 and 2009, many pterosaur workers prefer to toss out data that challenges traditions. On the plus side: doing so ensures publication in the present academic climate.

No longer requiring personal examination
of fossils, the authors report, “The Anurognathus ammoni described by Döderlein (1923) was measured using an image of the specimen published by David Hone online (here). The A. ammoni described by Bennett (2007b) was measured using an image published on the pterosaur.net website (here).”

Elgh et al. present several images of
pedal impressions, but they are isolated, so there is no confirmation of left or right identity. This is critical as some pterosaurs have a longest pedal digit 2, while others have a longest pedal digit 3. Others are sub equal. When three ungual bases are collinear most of the time those are digits 2–4, but not always. One Rhamphorhynchus specimen and Nemicolopterus goes the other way.

That statistic has implications for Elgh et al.
who identify four traced fossils with unguals aligned with digit 3 often the longest.

Below
I employ the first photo and first drawing by Elgin et al. (Fig. 2) and find an overlooked pedal morphology (in color overlay) and a strong similarity to an Early Cretaceous Beipiaopterus, a taxon not mentioned in the authors’ current text. Having a pedal digit 1 similar in length to the other three medial toes is very rare, so many other candidates are readily eliminated leaving this one and few to no others. Beipiaopterus nests in the LPT between a series of dorygnathids and a series of pre-azhdarchids, some of them from Solnhofen sediments.

Figure 1. Left and center images from Elgh et al. Colors and pes of Beipiaopterus added for comparison.

Figure 2. Left and center images from Elgh et al. Colors and pes of Beipiaopterus added for comparison.

Elgh et al. made no effort
at locating pedal pads or joints that correspond to pad/joint patterns in pterosaur pedes. By contrast, coloring the track reveals a typical pterosaur pes with a typical pad/joint pattern, but atypical phalanx lengths.

No pterosaur pedes in Peters 2011 are a perfect match,
but Early Cretaceous Beipaiopterus comes close.

Note that Elgh et al. ignored the curved impression
made by the elongate digit 5—because they were married to traditional paradigms, instead of going with the data as is.

I can only wish, at this point,
that future pterosaur workers add more precision to their studies and consider all possibilities… rejecting traditional hypotheses that cannot be validated, while embracing hypotheses that reflect reality.


References
unedited manuscript accepted for publication:
Elgh E, Pieńkowski G and Niedźwiedzki G 2019. Pterosaur track assemblages from the Upper Jurassic (lower Kimmeridgian) intertidal deposits of Poland: Linking ichnites to potential trackmakers, Palaeogeography, Palaeoclimatology, Palaeoecology, https://doi.org/10.1016/j.palaeo.2019.05.016
Peters D 2000a. Description and Interpretation of Interphalangeal Lines in Tetrapods.  Ichnos 7:11-41.
Peters D 2011. A Catalog of Pterosaur Pedes for Trackmaker Identification. Ichnos 18, 114-141.
Unwin DM 1996. Pterosaur tracks and the terrestrial ability of pterosaurs. Lethaia 29, 373-386.

Why do pterosaur workers ignore the most basic data?

I don’t know why,
but today’s leading pterosaur experts are actively ignoring the data from the last twenty years while inventing their own fanciful versions of what pterosaurs looked like (Fig. 1) – while claiming to be the latest word on the subject. Today we’ll be looking at a short paper from the latest Flugsaurier book by Hone, Witton and Martill 2017. And we’ll criticize the artwork that crystalizes their latest intentions. This is part 1.

For some reason
Hone, Witton and Martill like to show ancient cartoons that have little to no bearing on the present knowledge base (Fig. 1). I think it’s an English thing since most, if not all of the old engravings are indeed English in origin and easily lampooned. ‘See how far we’ve come!’, they seem to be saying. Doing so only takes up space that could otherwise go to competing current versions – which they want to avoid.

We’ve seen this
earlier when English professor D. Naish preferred to criticize work that preceded (= was not included in) ReptileEvolution.com. He employed cartoons made by others, rather than artwork that was actually posted on the website to show how bad the whole website was.

Evidently
It’s what they like to do. Someday, perhaps, they’ll look in a mirror and see some of the faults I present here… using their own artwork – which will soon enough joint their ancient engravings in a drawer full of foolish ideas they can draw upon in future decades.

Figure 1. Images from Hone, Witton and Martill 2017 showing the 'evolution' of our concept of Dimorphodon. Compare the latest color version to tracings of the several skeletons in figure 2.

Figure 1. Images from Hone, Witton and Martill 2017 showing the ‘evolution’ of our concept of Dimorphodon. Artists are credited in the text. Compare the latest color version to tracings of the several skeletons in figure 2. The long tail is based on a disassociated fossil probably belonging to a campylognathoid.

In figure 1
images of Dimorphodon through time are presented from Hone, Witton and Martill 2017.

  1. Rev. GE Howman 1829. Probably based on the headless holotype BMNH R1034 (Fig. 2). The authors labeled this as ‘monstrous’ when ‘inaccurate’, ‘fanciful’ or ‘medieval’ would do.
  2. Owen 1870. Probably based on the short-skull specimen, BMNH 41212 (Fig. 2), along with the disassociated tail specimen. The authors labeled this rendition as ‘ungainly, bat-like’. Odd word choice when among all the presented illustrations it is the one most like Witton’s 2017 version (#5).
  3. H Seeley 1901. Probably based on the long-skull specimen, BMNH PV R 1035 (Fig. 2) In the their comment Hone, Witton and Martill report, ‘progressive interpretation of D. macronyx as an erect-limbed quadruped’, but note that a biped interpretation was also offered. They thought it best not to show that possibility. 
  4. K Padian 1983. Probably based on the short-skull specimen, BMNH 41212 (Fig. 2). The authors report, ‘a highly active, bird-like digitigrade biped, a controversial interpretation that nevertheless symbolises the reinvention of pterosaurs in the late twentieth century.’ While there are minor issues associated with this figure (the orientation of fingers 1–3 and pedal digit 5, the over-extension of the metatarsophalangeal joint, the great length of the tail), it is the one that is most closely based on the skeleton (Fig. 2). BTW, when authors use the word, ‘controversial’ it usually means it does not fit their world view, but they have no evidence against it, nor any evidence to support their traditional hypothesis. 
  5. M Witton 2017. Not sure which skeleton this one is based on as it appears to have been done entirely freehand from memory and imagination. The authors report, ‘Modern interpretation of D. macronyx adult and speculative juveniles reflecting contemporary interpretations of pterosaur soft tissues, muscle development and ecology.’ Ahem…we’ll run through this illustration step-by-step below.

Figure 2. Images of Dimorphodon from ReptileEvolution.com. The tail attributed to Dimorphodon is shown in figure 3.

Figure 2. Images of Dimorphodon from ReptileEvolution.com. The tail attributed to Dimorphodon is shown in figure 3.

You know, you really can’t go wrong
when you strictly adhere to the bones (Figs. 2,3), soft tissue (Peters 2002) and footprints of the most closely related taxa (Peters 2011), which were made by digitigrade and bipedal pterosaur trackmakers. Unfortunately no such citations appear in this chapter. Those are purposefully omitted.

Dimorphodon model by David Peters

Figur 3. Dimorphodon model by yours truly. The tail is too long based on the disassociated tail.

Witton
fell under the spell of the quad-launch hypothesis (Habib 2008), then took it one step further and made Dimorphodon a galloping hunter (Fig. 4), forsaking its wings and erect, digitigrade hind limbs (according to related ichnite makers) to hunt prey on mossy logs with backward pointing fingers. The finger unguals are again too small here.

While writing this I became aware
of Sangster 2003, a PhD thesis that evidently used computer modeling to show Dimorphodon was a quadruped. I have not seen the thesis and Ms. Sangster can no longer be found online. I wonder about these conclusions because:

  1. PhD theses are, by definition, the work of inexperience workers; and
  2. Sangster may have had to earn her PhD by succumbing to the unveiled interests of her English professors, as we’ve seen before here and here.

Figure 4. Galloping Dimorphodon by Mark Witton.

Figure 4. Galloping Dimorphodon by Mark Witton.

To counter the awkward, dangerous and ultimately unproductive
quad-launch scenario, I proposed the following bipedal launch animation (Fig. 5). It combines the hind limb leap with the first flap of the large wings to provide the maximum thrust at takeoff. In the Habib proposal, you don’t get that wing flap until later in the cycle – maybe too late in the cycle. The quad launch also depends on directing the force of liftoff through the fragile free fingers. They were not strong enough for that, especialy not when there is a better option available using giant muscles in the chest and pelvis. That’s why the sacrum is so strong, to act as a fulcrum on that long, heavy lever!

FIgure 5. Dimorphodon take off (with the new small tail).

FIgure 5. Dimorphodon take off (with the new small tail).

So let’s get back
to Witton’s cover illustration (Fig. 6), which they tout as our contemporary view of Dimorphodon. I will note several inaccuracies (below). See figures 2 and 3 for accurate tracings.

Figure 6. Touted as the contemporary view of Dimorphodon, this Mark Witton illustration suffers from several fancies and inaccuracies.

Figure 6. Touted as the contemporary view of Dimorphodon, this Mark Witton illustration suffers from several fancies and inaccuracies.

  1. No Dimorphodon as this shape of skull.
  2. Needs a longer neck.
  3. Free fingers should be long and the unguals much larger.
  4. Wing appears to be too short with a too narrow wing tip chord.
  5. Witton wants to connect the trailing edge membrane from wing tip to ankle (or lateral toe), but look at the tremendous stretch in the membrane when that happens. Seems to be getting dangerously close to the narrow-at-the-elbow wing design of Zittel, Schaller and Peters, which they want to avoid.
  6. Ouch! This is a set of elongate toe bones with butt metatarsophalangeal joints – where Witton breaks them. This is not a calcar (a novel ossification on bat ankles which enters the uropatagium). One one side of these lateral toes the wing membrane attaches. On the other side the uroropatagium attaches. This is not shown in any fossil! Related taxa, from Langobardisaurus to Sharovipteryx, to Tanystropheus, with this same sort of elongate toe morphology, do not dislocate their bones this way. See Peters 2000 for a description that fits Rotodactylus tracks.
  7. No pterosaur has a uropatagium. This comes from a misinterpretation of Sordes. Pterosaur do have paired uropatagia.
  8. The tail is too large. On the BMNH 41212 fossil the traditionally overlooked tail is very small (Figs. 2, 7) This is in accord with related anurognathids. An unassociated tail has been attributed to Dimorphodon (Fig. 5) but it is robust and much longer. It probably belongs to a eudimorphodontid or campylognathoid. I”m surprised the tiny tail of Dimorphodon has gone unnoticed for so long. The specimen has been in English storage for over a hundred years. It was their responsibility for discovering this, but they chose instead to use their imaginations (Fig. 6).
  9. No tail vane is known for Dimorphodon. Tail vanes are found in pterosaurs like Campylognathoides and Rhamphorhynchus, both with a robust tail. Vestigial tails are unlikely to have had tail vanes.

FIgure 7. The tail of Dimorphodon (BMNH 41212 specimen). See figure 2 for reconstruction.

FIgure 7. The tail of Dimorphodon (BMNH 41212 specimen). See figure 2 for reconstruction.

I’m asking my Engllsh colleagues
|to step up their game and become more professional. Otherwise chaps from across the pond are going to continue pointing out the flaws in their thinking. I’m not going to say their approach is not scientific (as they say about my work), but when you forsake accuracy for artistry, you’re treading very close to that line.

References
Habib MB 2008. Comparative evidence for quadrupedal launch in pterosaurs. Zitteliana B28:159-166.
Hone DWE, Witton MP and Martill DM 2017.
New perspectives on pterosaur paleobiology in Hone DWE, Witton MP and Martill DM (eds) New Perspectives on Pterosaur Palaeobiology. Geological Society, London, Special Publications, 455, https://doi.org/10.1144/SP455.18
Peters D 2000. Description and Interpretation of Interphalangeal Lines in Tetrapods 
Ichnos, 7: 11-41.
Peters D 2002. A New Model for the Evolution of the Pterosaur Wing – with a twist 
Historical Biology 15: 277-301
Peters D 2011. A Catalog of Pterosaur Pedes for Trackmaker Identification.
Ichnos 18(2):114-141. http://dx.doi.org/10.1080/10420940.2011.573605
Sangster S 2003. The anatomy, functional morphology and systematics of Dimorphodon macronyx (Diapsida: Pterosauria)..Unpublished PhD thesis, University of Cambridge.

Padian 2017 examines pterosaur ankles with taxon and paper exclusion

I’ve had a long history with Dr. Kevin Padian,
one of the smartest paleontologists out there. He made important suggestions to my first book, GIANTS and early in his career made a name for himself by reporting on the bird-like traits of the Jurassic pterosaur, Dimorphodon. 

Unfortunately
Dr. Padian has a blind spot. He holds to the invalidated hypothesis that pterosaurs are related to dinosaurs, despite the complete lack of a series of archosaur taxa demonstrating a gradual accumulation of pterosaur traits. He still believes in the clade ‘Ornithodira.’

Ornithodira
Wikipedia reports, “Gauthier…coined and defined a slightly more restrictive node-based clade, Ornithodira, containing the last common ancestor of the dinosaurs and the pterosaurs and all of its descendants. Paul Sereno in 1991 gave a different definition of Ornithodira, one in which Scleromochlus was explicitly added.”

In the large reptile tree (LRT, 1094 taxa) the last common ancestor of dinosaurs and pterosaurs is the Devonian tetrapod, Tulerpeton at the base of the Lepidosaurormorpha – Archosauromorpha split.

Padian 2017
once again links pterosaurs with dinosaurs as he reviews with old illustrations the ankle bone ‘homologies’ of pterosaurs and archosaurs. Unfortunately he ignores Peters (2000a, b) who reidentified certain tarsals based on homologies with Cosesaurus and other fenestrasaurs (see below).

Figure 4. Peteinosaurus and Dimorphodon BMNH4212 pedes. Four tarsals are present on both.

Figure 1. Peteinosaurus and Dimorphodon BMNH4212 pedes. Four tarsals are present on both.

From the Padian abstract:
“The ankle bone assembly of pterosaurs has received little attention, even though it is critical for understanding the functional morphology of the leg and the foot and has far-reaching implications for interpretations of stance and gait in ornithodirans in general, as well as for any role the leg may have had in the flight of pterosaurs. Of particular importance are the distal tarsal bones, which are seldom preserved clearly.”

Padian found only two large (medial and lateral) tarsals in Dimorphodon, but most early pterosaurs have four tarsals (Fig. 1), as some of his figures show.  In Dimorphodon and Pteranodon the distal and proximal tarsals appear to fuse to one another creating two large side-by-side tarsals with a concave surface for articulation with the tibia/fibula. In all other pterosaurs the proximal tarsals are the astragalus and calcaneum. The ‘distal tarsals’ are actually distal tarsal 4 + the centrale sometimes accompanied by a tiny distal tarsal 3 (Peters 2000a) based on homologies with several tritosaur lepidosaurs, like Macrocnemus.

“Their concave proximal facets articulate with the medial and lateral condyles (comprising the astragalus and, at least basally, the calcaneum) of the tibiotarsus.”

The proximal tarsals are not part of the tibia in pterosaurs. Pterosaurs do not fuse the tibia and tarsus to form a tibiotarsus (Peters 2000a).

“Distally, they articulate with metatarsals II–IV, and the relatively large metatarsal V articulates on the distolateral side of the lateral distal tarsal.”

Not quite. That’s distal tarsal and the calcaneum articulate with metatarsal 5. That is exactly what happens, as Padian shows, in the archosauriforms Euparkeria, Crocodylus and Lagerpeton. That is exactly what also happens in the tritosaurs HuehuecuetzpalliMacrocnemus, Langobardisaurus, Cosesaurus and Sharovipteryx (Peters 2000a and ReptileEvolution.com).

“The homology of these bones in pterosaurs can be established with reference to other early-branching ornithodirans, and the morphology of the bones implies similar functional roles and ranges of motion.”

Convergence here with tritosaur lepidosaurs. Worth looking at.

“The medial distal tarsal is likely the fusion of distal tarsals 2 C 3, and the lateral distal tarsal is distal tarsal 4, a pattern reflected in ontogeny.”

No and yes. In tritosaurs distal tarsals 1–3 are tiny vestiges. Distal tarsal 3 is retained in many long-tailed pterosaurs. Distal tarsal 4 remains large. The proximal and distal elements fuse in Pteranodon. The medial centrale is Padian’s medial distal tarsal (Peters 2000a).

“The pterosaur ankle was capable of plantarflexion, but adduction and abduction of the feet were greatly limited.”

True.

“A synoptic survey of available tarsal bones of pterosaurs shows that the morphology of these bones remained relatively unchanged from the most basal pterosaurs to the pteranodontids and the azhdarchoids.”

True.

“Comparisons among a variety of ornithodirans show that the basic functional pattern did not vary importantly, although some ornithodiran subgroups evolved unique schemes of development and sequential ossification.”

True.

Dr. Padian writes:
“Pterosaurs were not thought to be particularly close to dinosaurs, or to any other archosaurs.”

When? That’s not current and traditional.

“Bennett, as noted above, does not accept that pterosaurs are ornithodirans. So it is all the more striking that these authors come to the same conclusion as functional morphologists who accept that pterosaurs are ornithodirans. The consensus of these authors is that pterosaurs, like dinosaurs and other ornithodirans, had a mesotarsal ankle that functioned as a hinge joint. Because the knee was also a hinge joint, as were the metatarso-phalangeal joint and the interphalangeal joints (Padian, 1983b, 1991), and the hip joint effectively allowed only protraction and retraction (see Schaeffer, 1956, and also Padian, 1983b), the gait would have been parasagittal and the stance erect (Padian, 2008). No argument has ever been made to counter these observations.”

No argument can be made to counter these observations. However, they can be expanded. Padian ignores the fact that other clades, like lepidosaurs, are also capable of bipedal locomotion and that some (like those list above) also have a simple hinge ankle joint. He also fails to note that in some pterosaurs the femoral head is at right angles to the shaft, but in others it is almost in line with the shaft, creating a splayed femur, like a lepidosaur, yet, like certain lepidosaurs, still capable of erect bipedal locomotion (Fig. 2).

Padian discusses the splayed femur concept
and agrees with Unwin that it would have provided a clumsy, sprawling gait. This is incorrect as anyone can learn from making museum-quality skeletons that have splayed femora and erect hind limbs. The angles all work out (Fig. 2).

And running bipedal lizards are not clumsy. They are speedy wonders!

Standing Pteranodon

Figure 2. Standing Pteranodon with sprawling femora. We’ve known this for 17 years.

Way back in the 1980s,
Kevin Padian and Chris Bennett. in the same conversation. cautioned me to employ phylogenetic analysis in my studies. Given present data in the academic literature (Peters 2000a, b) you have to ask yourself why Padian, like Bennett (2012) restricted his taxon list to just archosauromorphs.

For those who wonder why I don’t publish,
maybe Padian’s paper will offer some insight. I have published several papers on pterosaur relationships, wings and feet. None were cited by Dr. Padian. He is listed in the acknowledgments of Peters 2000a for reading an earlier version of the manuscript. The last time we e-mailed he was angry that I made several of the above observations.

References
Bennett SC 2012. The phylogenetic position of the Pterosauria within the Archosauromorpha re-examined. Historical Biology. iFirst article, 2012, 1–19.
Padian K 1983. 
Osteology and functional morphology of Dimorphodon macronyx (Buckland) (Pterosauria: Rhamphorhynchoidea) based on new material in the Yale Peabody Museum, Postilla, 189: 1-44.
Padian K 2017.
Structure and evolution of the ankle bones in pterosaurs and other ornithodirans. Journal of Vertebrate Paleontology.
DOI: 10.1080/02724634.2017.1364651
Peters D 2000a. Description and Interpretation of Interphalangeal Lines in Tetrapods.  Ichnos 7:11-41.
Peters D 2000b. A Redescription of Four Prolacertiform Genera and Implications for Pterosaur Phylogenesis. Rivista Italiana di Paleontologia e Stratigrafia 106 (3): 293–336.

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.

Eurazhdarcho and LIPB R 2.395: two new azhdarchid pterosaurs

Two European azhdarchids
have become known recently. Eurazhdarcho langendorfensis EME VP 312/2 (Vremir et al. 2013, Fig. 2) and the unnamed LIPB R 2.395 (Vremir et al. 2015. Fig. 1). Eurazhdarcho is known from a distal mc4, a proximal m4.1 and a proximal mt3 (not a distal mc3 as originally labeled, see below), plus cervicals 3 and 4. LIPB R 2.395 is known from a cervical 4 only.

What little is known indicate that both are similar in size and proportions to Zhejiangopterus. And they are just as gracile.

Figure 1. LPB-(FGGUB)-R.2395 cervical 4 with other cervicals imagined.

Figure 1. LPB-(FGGUB)-R.2395 cervical 4 with other cervicals imagined.

The re-identification
of distal metacarpal 3 in Eurazhdarcho (Figs. 2, 3) as metatarsal 2, 3 or 4 is based on the shape of the bone in question. It is expanded asymmetrically proximally and flattened as preserved in situ in Eurazhdarcho (Figs 2, 3) and Quetzalcoatlus (Fig. 4). By contrast distal metacarpal 3 in all pterosaurs has a convex articular surface to accommodate an unrestricted metacarpophalangeal 3 joint permitting extreme extension for implanting posteriorly while walking.

Figure 2. Eurazhdarcho with mc3 reidentified as mt3.

Figure 2. Eurazhdarcho with distal mc3 (in red and in figure 3) re-identified here as proximal portion of metatarsal 2, 3 or 4.

The in-situ placement
of the bone in question (Fig. 2) on the fossil near metacarpal 4 cannot be valid evidence because the cervicals are also extremely displaced. These bones became a jumbled mess long after the body had disintegrated and these few scattered elements were fossilized.

Figure 3. Close up of bone labeled distal mc3. This looks more like proximal mt3.

Figure 3. Close up of bone labeled distal mc3 in Eurazhdarcho. This looks more like a proximal metatarsal in Quetzalcoatlus in figure 4. There is no spherical articulation surface here that would indicated a distal metacarpus. The pink area is a restoration that could represent a much longer distal metatarsal.

The metatarsus of Quetzalcoatlus (Fig 4)
provides comparable data for the Eurazhdarcho bone in question. Metatarsal 4 is shown because it shows better on the lateral edge of the foot. Metatarsal 3 lies beneath it. Both appear to be a good match.

Figure 3. Metatarsal 3 in Quetzalcoatlus looks like the same bone in Eurazhdarcho labeled as a distal metacarpal 3.

Figure 4. Metatarsal 3 in Quetzalcoatlus looks like the same bone in Eurazhdarcho labeled as a distal metacarpal 3. Click to enlarge.

Good to see
mid-sized azhdarchids in eastern Europe to go with the giant Hatzegopteryx, also known from scraps.

I sincerely hope
one of the authors of both papers, Darren Naish, is not too upset by this reinterpretation. We’ve heard from him before. I confess: I used DGS. Never saw the actual fossil. And I don’t have a PhD. Did I make a mistake? Let me know and a change will be made.

References
Vremir MTS, Kellner AWA, Naish D, Dyke G 2013. Laurent  V, ed. A New Azhdarchid Pterosaur from the Late Cretaceous of the Transylvanian Basin, Romania: Implications for Azhdarchid Diversity and Distribution. PLoS ONE 8: e54268.
Vremir MTS, Witton M, Naish D, Dyke G, Brusatte SL, Norell M and Totoianu R 2015. A medium-sized robust-necked azhdarchid pterosaur (Pterodactyloidea: Azhdarchidae) from the Maastrichtian of Pui (Haţeg Basin, Transylvania, Romania). American Museum Novitaes 3827 16 pp.

 

New Mexican Pterosaur Tracks?

Figure 1. I'd like to see 4 toes if this is indeed a pterosaur track. Here three toes points toward a theropod.

Figure 1. I’d like to see 4 toes if this is indeed a pterosaur track. Here three toes suggest a theropod.

Recent announcement of 110 million-year-old pterosaur tracks by Raul Frank Gio Argáez, researcher at the Institute of Marine Sciences and Limnolog , National Autonomous University of Mexico (UNAM ) made the news here.

Unfortunately all pterosaur tracks that I am aware of have four toes.

Here (Fig. 1) the fourth toe appears to be missing, suggesting a misidentification. Looks more like a theropod track. If anyone can see the fourth toe, please let me know.

Behind the Scenes at the AMNH pterosaur exhibit

Here‘s a NY Times article about the new AMNH pterosaur exhibit. We looked at the AMNH pterosaur exhibit website earlier here. The online article url was sent to me by “I love pterosaurs” who wants me to “Please, learn how real scientist work.” [sic]

Okay, let’s see how real scientists work.
The following is from the online article (unfortunately, only a fraction focused on the pterosaurs and their artistic creation):

“Most of the questions that we actually get from artists, the answer is, ‘I don’t know,’” Dr. Kellner said. But the more research that’s done, the closer their guess can be on an animal that’s been extinct for 66 million years.

“In art you can do whatever you want,” Dr. Kellner said. “You have an expression of how you feel about a certain subject. But in paleo art, you don’t have that liberty. You must try to present the reconstruction of those animals the best way that you can based on true scientific evidence.”

“Sometimes, changes in science happen so quickly that an artist’s creation must be considerably altered. The feet of Quetzalcoatlus underwent major changes as well: Five toes per foot were edited down to four; they were shortened and the toenails removed.”

Sounds like the artists are getting good advice “based on scientific evidence” from the curators, but then…

Good gravy!
I haven’t seen any pterosaurs with four toes. There’s always a vestige to #5. And if these are the toes (they’re big ones, Fig. 1) the AMNH is advertising their inaccuracies early. Someone must have been influenced by theropods here (Fig. 1) because azhdarchid toes don’t go short on number 1.

Figure 1. Based on their size, these must be the Quetzalcoatlus feet and hands. I've added some real azhdarchid feet and ichnites here. Metatarsals should be appressed to match the fossils and tracks. All metatarsals should be subequal. Claws are not supported be really big. It's too bad no one looked at the data here.

Figure 1. Based on their size, these must be the Quetzalcoatlus feet and hands. I’ve added some real azhdarchid feet and ichnites here. Metatarsals should be appressed to match the fossils and tracks. All four medial metatarsals should be subequal. Claws should not be so thck. Remember the bones are more like soda straws than robust dino feet. It’s too bad no one looked at the data here.

Azhdarchid feet were narrow, with appressed metatarsals, as their fossils and ichnites show (Fig. 1). The evidence does not support these feet.

However
Not all giant pterosaurs were azhdarchids. Earlier we looked at some wider giant bipedal Korean pterosaur tracks here, likely made my tapejarids or shenzhoupterids with webbed feet, as shown in the AMNH feet (Fig. 1) . Even so four long metatarsals and toes is the rule. If the above pterosaur made tracks they would be mistaken for theropod tracks.

Figure 2. Basic errors in the big Quetzalcoatlus model.

Figure 2. Basic errors in the big Quetzalcoatlus model. The short wings and ultra size give away the genus.

Damn, I hate to see this.
I know those artists are working hard to get things as accurate as possible. So don’t blame them. They’re only taking orders.

On the good side:
The color, texture and size of the model pterosaurs is great. And so is their presentation. I just think they missed the excitement of pterosaurs the way the fossils reveal them to be.

And that’s the reason behind this blog. It’s a crusade for scientific accuracy supported by evidence.

Quetzalcoatlus in dorsal view, flight configuration.

Figure 3. Quetzalcoatlus in dorsal view, flight configuration based on bones from Q sp.  and wing membranes form other pteros.

Which pterosaur does this foot belong to?

Figure 1. This appears to be a classic basal pterosaur foot, but what kind? Note the presence of the ungual on digit 5. That's exciting!

Figure 1. This appears to be a classic basal pterosaur foot, but what kind? Note the presence of the ungual on digit 5. That’s exciting! So is that extra phalanx.

Here (Fig. 1) is what appears to be a classic basal pterosaur foot. Long narrow metatarsals. Metatarsals 3 and 4 are the longest, as in Preondactylus and Austriadactylus (SC332466). Pedal 5.1 extends beyond metatarsal 4, as in Austriadactylus and Dimorphodon. Digit 4 is slightly longer than digit 3. Digit 5, though, appears to have an extra phalanx or two. That astragalus is oddly shaped, but everything else seems to be very pterosaurian…

Did you guess? Or did you know?
This is Tanystropheus, a close relative to the ancestors of pterosaurs. Langobardisaurus and Cosesaurus are closer to that common ancestor and to each other.  And they both have this kind of foot.

Homoplasy, not Convergence
Those similar foot characters are homoplastic, not the result of convergence and attests to the antiquity of this foot morphology in the lineage of pterosaurs. Now, if we can only get the powers that be to start including Tanystropheus, Langobardisaurus, Cosesaurus (and the rest of the Fenestrasauria) with pterosaur and archosaur studies, it would be no surprise to find out where pterosaurs actually do nest in the scheme of things.

Archosaurs, as you already know, have only a vestige or less of a fifth pedal digit. This is where you start looking for the ancestors of pterosaurs.

And if you’re an archosaur-lover ~ take your blinders off.