Matthew Baron 2020 brings us a massively flawed view of pterosaur in-group and out-group relations. The flaws are due to taxon exclusion.
Unfortunately
Baron holds onto the tradition nesting pterosaurs with archosaurs creating the invalid clade “Ornithodira“. He writes, “the omission of other ornithodirans and avemetatarsalians has the potential to adversely affect the results of phylogenetic analyses.”
That should have been a red flag. In Peters (2000, 2007) the large reptile tree (LRT, 1714+ taxa) small furry pterosaurs with long fingers and toes arise from small furry lepidosaurs (Fig. 1) with long fingers and toes. In the LRT deletion of clades rarely affects tree topology. Those lepidosaurs were ignored by Baron 2020.
Baron ignores some of the peer reviewed literature when he writes, “no transitional non-flying pterosaur taxa are known (though some specimens have been suggested to be exactly that)”.
To his credit, Baron 2020 notes, “The purpose of outgroup taxa is to reflect, as best as is possible, the ‘basal’ condition for the ingroup clade being studied—it is arguable that this is not the case in the analyses by Britt et al. (2018) and Dalla Vecchia (2019) and that these analyses fall short in this key respect.” and “Other studies of early pterosaur interrelationships have similar shortcomings in terms of the outgroup taxa sampling.”
To his discredit, Baron notes, “While Scleromochlus taylori was considered as a possible close relative of pterosaurs at the time Kellner (2003) was published, subsequent work on this taxon has demonstrated that it is more likely an archosauriform belonging to the clade Doswelliidae (see, Bennett, 2020).
Suggestion: keep adding taxa until Scleromochlus stops moving around. That will happen when you add several small, bipedal crocodylomorphs.
Figure 1. Bergamodactylus compared to Cosesaurus. Hypothetical hatchling also shown. Makes more sense than Postosuchus or Marasuchus.
Looking for lost keys where no one dropped them, Baron writes, “This study aims to test what effect, if any, the omission of such close pterosaur relatives from analyses has had on the overall topology within Pterosauria, Britt et al. (2018) and Dalla Vecchia (2014, 2019) could be resolved through a simple addition of better and more appropriate outgroup taxa, and this is what this study attempts to do. By also incorporating new anatomical characters, taken from recent early dinosaur and archosaur studies, this study aims to better anchor the base of Pterosauria to a position within Avemetatarsalia and Ornithodira, so as to allow the ‘basal’ condition of pterosaurs to be better expressed in the data.”
None of the taxa recovered as pterosaur ancestors by Peters 2000 (e.g. Langobardisaurus, Cosesaurus, Sharovipteryx and Longisquama) were mentioned in Baron 2020 fulfilling Bennett’s curse, “You will not be published, and if you do get published, you will not be cited.” We can also blame a long list of pterosaur workers acting as referees for keeping these taxa off of Baron’s radar, compelling him to use some useless (for these purposes) archosauriforms and archosaurs.
Baron’s initial cladogram is completely unresolved
at the base, both within and outside the Pterosauria. The LRT does not have that problem. In addition, Baron’s taxon list includes way too few taxa relative to the large pterosaur tree (LPT, 250 taxa) and fails to recover four distinct pterodactyloid-grade clades.
Baron’s second cladogram resolves the outgroup problem and recoveres the small theropod, Marasuchus, and the proterochampsid, Lagerpeton, as outgroup taxa. Both have a vestige pedal digit 5, which makes evolving a lepidosaur-like long pedal digit 5 in basal pterosaurs impossible. Neither preserves a skull, which is a problem, especially when good skulls are known for Langobardisaurus, Cosesaurus, Sharovipteryx and Longisquama and these share many traits with basal pterosaurs (Fig. 1).
The basalmost pterosaur in the LRT and LPT, Bergamodactylus (MPUM 6009, Fig. 1) is not mentioned in the Baron 2020 text.
Baron’s discussion includes the phrase, “much work needs to be done to further broaden the datasets used in phylogenetic analyses, in terms of both the operational taxa and anatomical characters and character states.”
Actually that work has already been done. As a resut, so much taxon exclusion in Baron’s 2020 study means it was a complete waste of the author’s time, efforts and expense. Add taxa, Matthew Baron, and all the problems created by your colleagues will disappear with complete resolution.
Which raises the final question, How long is the sort of taxon and literature exclusion described above going to keep appearing in the literature? Add taxa. That’s all the LRT and LPT keep telling us.
Figure x. Subset of the LPT focusing on Triassic pterosaurs.
References Baron MG 2020. Testing pterosaur ingroup relationships through broader sampling of avemetatarsalian taxa and characters and a range of phylogenetic analysis techniques. PeerJ 8:e9604 DOI 10.7717/peerj.9604 Huene Fv 1914. Beiträge zur Geschichte der Archosaurier. Geologische und paläontologische Abhandungen, NF 13:3–53. Peters D 2000. Description and Interpretation of Interphalangeal Lines in Tetrapods. Ichnos 7:11-41. Peters D 2007. The origin and radiation of the Pterosauria. In D. Hone ed. Flugsaurier. The Wellnhofer pterosaur meeting, 2007, Munich, Germany. p. 27.
Figure 1. The Solomon Islands skink (Corucia zebrata) is the largest skink on the planet, gives birth with a placenta and lives in communities.
This nesting comes as no surprise. After all, skeletally Corucia is just another widely recognized skink, albeit with some unique reproductive and social qualities (see below).
Figure 2. The skink, Corucia zebrata with DGS colors added.
Do not confuse Corucia with Carusia
(Fig. 3). The two are not the same, nor are they closely related.
Figure 3. Carusia intermedia, a basal lepidosaur close to Meyasaurus now, but looks a lot like Scandensia. Note the primitive choanae and broad palatal elements. None of the data I have shows the caudoventral process of the jugal, so I added it here from the description. Same with the epipterygoid.
Corucia zebrata (Gray 1855, Figs. 1, 2) is the extant Soloman Islands skink, the largest known extant species of skink. Long chisel teeth distinguish this herbivorous genus. The tail is prehensile. This is one of the few species of reptile to live in communal groups. Rather than laying eggs, relatively large young are born after developing within a placenta. Single babies are typical. Twins are rare according to Wikipedia.
Removing all Carusia sister taxa in the LRT
fails to shift Carusia from its traditionally overlooked node basal to squamates.
The Wikipedia entry
on the ‘clade’ Carusioidea excludes great swathes of taxa relative to the LRT, so it mistakenly suggests that extinct Carusia is a member of the Squamata. Adding pertinent taxa solves that problem, as the LRT demonstrates.
References Gray JE 1855. (1856). New Genus of Fish-scaled Lizards (Scissosaræ), from New Guinea. Annals and Magazine of Natural History, Second Series 18: 345–346.
Paleo-photographer Helmut Tischlinger 2020
brings us extreme closeups of the first pterosaur ever described, Pterodactylus antiquus (Figs 1–7), in white and UV light. Here both photos of the same area are layered precisely to demonstrate the different details each type of light brings out.
The text is German.
The abstract and photo captions are duplicated in English.
Pterodactylus antiquus (Collini 1784, Cuvier 1801, 1809, Sömmerring 1812, BSP Nr. AS I 739, No. 4 of Wellnhofer 1970; Late Jurassic) was the first pterosaur to be described and named.
Figure 1. Reconstruction of Pterodactylus antiquus made prior to Tischlinger 2020.
From the Abstract: “On the occasion of the reopening of the Jura Museum Eichstätt on January 9, 2020, the Bavarian State Collection for Paleontology and Geology, Munich, provided the Jura Museum with one of its most valuable fossil treasures as a temporary loan. The “Collini specimen”, first described in 1784, is the first scientifically examined and published fossil of a pterosaur and has been at the center of interest of many natural scientists since it became known… An examination of the texture of the surface of the limestone slab and the dendrites on it suggests that it does not come from Eichstätt, as has been claimed by Collini, but most likely from the Zandt-Breitenhill quarry area about 30 km east of Eichstätt. For the first time, a detailed investigation and pictorial documentation were carried out under ultraviolet light, which on the one hand document the excellent preservation of the fossil, and on the other hand show that there has obviously been no damage or manipulation to this icon of pterosaurology during the past almost 240 years.”
Figure 2. Pterodactylus wing ungual in white light and UV. Not sure why the two images are not identical, but elsewhere teeth appear and disappear depending on the type of light used.
The wing tip ungual
appears to be present in visible light, but changes to a blob under UV (Fig. 2). Other pterosaurs likewise retain an often overlooked wingtip ungual.
In the same image
the skin surrounding an oval secondary naris within the anterior antorbital fenestra appears. Otherwise very little soft tissues is preserved.
The ‘secondary naris’ may be a new concept for some,
so it is explained below. This is not the same concept as the hypothetical ‘confluent naris + antorbital fenestra’ you may have heard about. Remember, ‘pterodactloid’-grade pterosaurs arose 4x by convergence. So each had their own evolutionary path.
Figure 3. Pterodactylus rostrum from Tischlinger 2020, colors added here. Note the original naris appears as a vestige above the maxilla tip, as in the Triassic pterosaur, Bergamodactylus and the Pterodactylus ancestor, Scaphoganthus. The shape of that narial opening is different in UV and white light.
The elements of the paper-thin rostrum are colorized here (Fig. 3). There are subtle differences between the white light and UV images. The pink color represents a portion of the nasal that extends to the anterior maxilla and naris as in other pterosaurs and tetrapods. Did I just say naris? Yes.
Note the original naris here appears as a vestige
in its usual place above the maxilla tip, as in the Triassic pterosaur, Bergamodactylus and the late-surviving Pterodactylus ancestor, Scaphoganthus. The transition to this vestigial naris is documented in the rarely published n9 (SoS 4593), n31 (SoS 4006) and SMNS 81775 tiny transitional taxa (Fig. 4). After testing, all these turn out to be miniaturized adults traditionally mistakenly considered to be juveniles, only by those pterosaur workers who have excluded these taxa from phylogenetic analysis.
Figure 4. Click to enlarge. Painten pterosaur compared to phylogenetic sister taxa. Ornithocephalus and SMNS 81775 are the basal taxa here. Note that while everything else grows on derived taxa, the metacarpus stays the same size. The large size of the Painten pterosaur, along with the greater length of pedal digit 3 and the brevity of the metacarpus sets it apart in its own clade, of which this the first known representative. Larger than its relatives, this is an unlikely juvenile (contra Hone, see below).
That’s why it is so important
to include all pterosaurs specimens as taxa in analysis. Otherwise you will miss the phylogenetic miniaturization that occurs at the genesis of major clades, the phylogenetic variation within a genus, and the evolution of new traits that have been overlooked by all other pterosaur workers.
Figure 5. Pterodactylus metacarpus including 5 digits. Colors added here.
The elements of the right metacarpus
are better understood and communicated when colorized (Fig. 4). Not sure where the counter plate is, but it may include some of the elements missing here, like the distal mc1. The left manus digit 5 is on that counter plate, judging from the broken bone left behind on the plate.
Figure 6. Pterodactylus antiquus pes in situ and restored to in vivo appearance.
The pes is well preserved Adding DGS colors to the elements helps one shift them back to their invivo positions. The addition of PILs (parallel interphalangeal lines, Peters 2000) complete the restoration. This is a plantigrade pes, judging by the continuous PILs that other workers continue to ignore.
Figure 7. Pterodactylus in situ under white light and UV from Tischlinger 2020. Colors added here.
Sometimes PhDs overlook certain details.
And that’s okay. Others will always come along afterward to build on their earlier observations. Tischlinger 2020 provides that excellent opportunity.
References Collini CA 1784. Sur quelques Zoolithes du Cabinet d’Histoire naturelle de S. A. S. E. Palatine & de Bavière, à Mannheim. Acta Theodoro-Palatinae Mannheim 5 Pars Physica, 58–103. Cuvier G 1801. [Reptile volant]. In: Extrait d’un ouvrage sur les espèces de quadrupèdes dont on a trouvé les ossemens dans l’intérieur de la terre. Journal de Physique, de Chimie et d’Histoire Naturelle 52: 253–267. Cuvier G 1809. Mémoire sur le squelette fossile d’un reptile volant des environs d’Aichstedt, que quelques naturalistes ont pris pour un oiseau, et dont nous formons un genre de Sauriens, sous le nom de Petro-Dactyle. Annales du Muséum national d’Histoire Naturelle, Paris 13: 424–437. Peters D 2000. Description and Interpretation of Interphalangeal Lines in Tetrapods. Ichnos, 7: 11-41 Tischlinger H 2020. Der „Collini-Pterodactylus“ – eine Ikone der Flugsaurier-Forschung Archaeopteryx 36: 16–31; Eichstätt 2020. von Soemmering ST 1812. Über einen Ornithocephalus. Denkschriften der Akademie der Wissenschaften München, Mathematischen-physikalischen Classe 3: 89-158. Wellnhofer P 1970. Die Pterodactyloidea (Pterosauria) der Oberjura-Plattenkalke Süddeutschlands. Abhandlungen der Bayerischen Akademie der Wissenschaften, N.F., Munich 141: 1-133.
It happened over the past several months to Xing et al. 2020 after they published in Nature on their hummingbird-sized ‘dinosaur’ in amber, Oculudentavis. Then, oops! Everyone else recognized the specimen as a lepidosaur. Last week Nature and the publicly-shamed authors retracted the paper with a fair amount of bad press.
Meanwhile, on a more personal note…
imagine examining fossils across the ocean without a science degree and ‘discovering’ four overlooked ancestors to pterosaurs (Peters 2000; Fig. 2). None had been identified before and no others have been identified since. Actually these pre-pterosaurs were recovered by adding their data to four previously published phylogenetic analyses, not by finding fossils in the field. Unfortunately (and this is true), for the next twenty years that paper, that discovery and several that followed (Peters 2002, 2007, 2009) were never cited in a supportive sense. Instead these peer-reviewed papers were shunned and ignored.
Worse yet,
imagine a gathering of PhDs rising against you online. Some call you a ‘hack’ even though you followed all the rules and did all the work with the proper citations, acknowledgements and peer review. When one studies specimens and writes papers, the furthest thing on your mind is a future with online shaming from the cancel culture.
Figure 1. Scene from Animal House after Otter walks into a hotel room with roses for his rendezvous, only to meet the five frat boys ready to deliver a little punishment.
All is not lost. Patience is the watchword here. No one else can ‘discover’ these interrelationships (Fig. 2). They are time-stamped in the academic literature. Perhaps the best thing one can realize is: the enmity coming from other scientists turns out to be a relatively common phenomenon.
The question is:
why do some scientists demonize and shun discoverers?
Figure 2. The lineage of pterosaurs recovered in Peters 2000 and from the large reptile tree. Huehuecuetzpalli. Cosesaurus. Longisquama and MPUM 6009 (Bergamodactylus).
“We will reduce somebody to a label. We’ll reduce somebody to the worst tweet that they ever wrote. We’ll demonize them and then we’ll de-humanize them, because we’ve just destroyed somebody and we don’t want to feel bad about destroying them so we call them ‘sociopath’ or something.”
“It’s a whole mental trick we play on ourselves. Like, cognitive dissonance. We’re good people, but we just destroyed somebody. So how do we make sense of that?”
“So it’s all about labeling and reducing and demonizing people we don’t like.”
Then Joe Rogan pipes in: “And it’s also an excuse to be a real asshole. Like all you have to do is find a reason to unleash your fury on people. And it’s a free shot.”
Whenever someone calls you a ‘hack’, try to see things from their point-of-view. Do they have a point? Is there something you have to do to ‘clean up your act?’ If so, then clean up your act. Do more than is expected. Add taxa. Trace details. Show your work. Double check your results for errors. Write to experts for their advice (but be wary if they try to send you snipe hunting). After you’ve done all that, all to no avail, then consider the following…
Sometimes personal attacks are the result of unfulfilled expectations.
After all, some paleontologists spend a lot of money and many years getting a PhD only to find out professorial jobs are as rare as bird teeth. Discoveries are even harder to come by, whether in the field or by fossils occasionally sent to them.
So, it’s no wonder PhDs are pissed off
when a nobody from a small town in middle America starts harvesting the literature, adding taxa to a growing online vertebrate cladogram and making discoveries several times a week. That cladogram, the core of ReptileEvolution.com, now exceeds in size and breadth any vertebrate study ever published (samples from 1700+ fish to humans are included). New insights were recovered just by testing taxa together that have never been tested together before (like pterosaurs and lepidosaurs, Fig. 2).
The unfortunate fact is: the list of discoveries waiting to be discovered
is limited and it gets shorter everyday. Today’s young paleontologists earned their PhDs in order to make those rare discoveries. So, imagine their wrath when an unschooled outsider showed them their expensive and time-consuming education was not really necessary, at least at this stage in paleontology. What was necessary was a comprehensive review of the literature and a single wide gamut test to reveal where taxon exclusion had resulted in traditional false positive results.
Getting back to Animal House for a moment… Otter thought he was going to get a little romance the night he opened the door to a motel room, with the cheerful line, “It’s “Mr. Thoughtful” with a dozen roses for… you…” only to be met by a cadre of frat boys ready to pummel him (Fig. 1). Likewise, twenty years ago when I recovered four pterosaur ancestors, I thought good things would follow. Alas, that still has not happened. Nothing but ostracizing and enmity has followed.
Sadly, some of the things you learn in paleontology
are not found in textbooks. One is the extremely slow pace of acceptance in this field.
Remember it took paleontologists 150 years
to elevate the tails of tail-dragging dinosaurs and to realize birds were dinosaurs. It will take them more than twenty years to realize pterosaurs were lepidosaurs. Unlike other sciences, paleontological discoveries and recoveries, especially from outsiders, are not welcome.
So, if you make a discovery, take your punishment cheerfully and maintain your scientific work ethic. Be patient. If you play it straight, and put the work in, you already know how this movie is going to end. Starting off, your only allies will come out of the ‘Delta House‘ fraternity, but soon you’ll have the whole audience on your side.
Good luck on your scientific journey.
Rest assured that others have been through whatever you’re going through now.
Hope this ‘futile and stupid gesture’ helps.
Postscript:
It’s no wonder that some workers thought Oculudentavis was a bird, while others thought it was a lepidosaur. After testing all known candidates, it turns out Oculudentavis was a late-surviving sister to Cosesaurus (Fig. 2), which was originally and mistakenly considered a Middle Triassic bird ancestor (Ellenberger and DeVillalta 1974). Later Peters (2000, 2007) recovered Cosesaurus as a lepidosaur and a flapping pterosaur ancestor. So, these related taxa tell the same story.
All this confusion over Oculudentavis could have been avoided
if the pterosaur community had not shunned and shamed the results of Peters 2000, 2002, 2007, 2009. Due to that suppression the bird-like lepidosaur, Cosesaurus, was not on the radar of Xing et al. and it was not tested to ascertain relationships.
And that’s how the ripples radiate.
Rarely to never cited references: Ellenberger P and de Villalta JF 1974. Sur la presence d’un ancêtre probable des oiseaux dans le Muschelkalk supérieure de Catalogne (Espagne). Note preliminaire. Acta Geologica Hispanica 9, 162-168. Peters D 2000. A Redescription of Four Prolacertiform Genera and Implications for Pterosaur Phylogenesis. Rivista Italiana di Paleontologia e Stratigrafia 106 (3): 293–336. Peters D 2002. A New Model for the Evolution of the Pterosaur Wing – with a twist. – Historical Biology 15: 277–301. Peters D 2007. The origin and radiation of the Pterosauria. In D. Hone ed. Flugsaurier. The Wellnhofer pterosaur meeting, 2007, Munich, Germany. p. 27. Peters D 2009. A reinterpretation of pteroid articulation in pterosaurs. Journal of Vertebrate Paleontology 29:1327-1330. Xing L, O’Connor JK,; Schmitz L, Chiappe LM, McKellar RC, Yi Q and Li G 2020. Hummingbird-sized dinosaur from the Cretaceous period of Myanmar. Nature. 579 (7798): 245–249.
And finally this carbon copy reply to a recent (2020) TetZoo blogpost by PhD Darren Naish, doubling down on his earlier (2012) blogpost, “Why the World Has to Ignore ReptileEvolution.com“. This was followed by a long list of comments by a cadre of angry paleontologists.
“Well, fellas, that’s a lot to drink in. Thank you for all the attention.
ReptileEvolution.com is an online experiment in which I learn as I go. Just like a professional. True, I made over 100,000 errors in scoring or drawing over the last nine years. In understand in science that’s part of the process.
A few points worth considering:
Taxon exclusion is the issue I bring up over and over again. Just add pertinent taxa, score correctly and see what PAUP delivers. Shouldn’t be too hard. Add some placoderms to some catfish taxa. Add some caseasaurs to millerettids. And show your work.
Cau’s study on pterosaurs arising from Scleromochlus (a basal bipedal crocodylomorph) seems odd given that the hand is so small in Scleromochlus and the foot lacks a long toe 5, etc. etc. No illustrations accompany the cladogram, so we don’t know what characters were correctly or incorrectly scored for Sharovipteryx and Cosesaurus. I show my work. Ellenberger thought Cosesaurus was a Middle Triassic bird ancestor and I could not convince him otherwise. So whatever the problem is, it’s common and I’m used to it.
Yi qi: seriously? Please send data on both ulnae, both radii and the both styliforms. I will make the change to create the flying dragon if you can show valid data. Ball is now in your court.
Figure 3. Darren Naish did not like the more precise tracing made by yours truly. He though I was seeing things. The tracing at upper left is the original published tracing by the fossil describers.
Hey, Darren, what’s wrong with that tracing of Jeholopterus skull? (Fig. 3) I provided a competing tracing (upper left hand corner). Is that all you got? After 17 years mine is still accurate and all the parts fit together in appropriate patterns. Bennett’s anurognathid skull, which you prefer, mistook a maxilla for a giant scleral ring. But the right giant scleral ring was never found. Nor were any giant scleral rings ever found on any other anurognathids. Let me know if and when you find one.
Figure 4. Chicken skull (Gallus gallus) with fused and semi-fused skull bones colorized. Postorbital = orange. Squamosal = tan. Lacrimal = brown. Prefrontal = purple. Quadrate = red. No one else has ever attempted to do something similar.
re: that chicken skull colored photo {FIig 4}: please provide a competing image that shows what a ‘real’ chicken skull is all about. I’d like to know where the errors are so I can fix them. I prefer to use rather than create.
re: genomics vs. phenomics. Didn’t the taxon list in Afrotheria cause you to wonder, even a little bit? Gene studies produce false positives over deep time. You can test it yourself. If an amateur can do it, so can you.
If I forgot to address a favorite criticism, let me know. You guys provided a long list. At present, it’s better to be brief and to the point.
The large reptile tree (1712+ taxa) plus the pterosaur tree and therapsid skull tree all produce cladograms that recover sister taxa that actually look like each other (not like pterosaurs arising from Scleromochlus). All three are constantly being updated as I find errors. The LRT demonstrates you can lump and split 1712 taxa using only 230 multistage characters. That’s a fact. More taxa are more important than more characters. That’s a fact.
This is something the paleo community has asked for. But the order of taxa is not what you asked for. Where is the competing study? If you’ve been sitting on your hands and/or writing to Darren Naish, you’ve been wasting your time. Do what you are paid to do. Or wait until you retire and have gobs of time, like me. — David Peters”
Konietko-Meier et al. 2020 discover digit 5
where they did not expect to find one, on Metoposaurus (Figs. 1-3).
Figure 1. Ozimek hitching a ride on top of Metoposaurus. Note the relatively large manus and pes here compared to figure 2.
We’ve long wondered, how many fingers did the first tetrapod have?
If more than five, when did four or five come to be?
If five, when did four or more than five come to be?
If four, when did five or more than five come to be?
Figure 2. Metoposaurus in several views. Smaller hands and feet on this data lacking digit 5.
From the Konietko-Meier et al. 2020 introduction: “In contrast to crown tetrapods that rarely have more than five digits, basal tetrapod groups possessed more digits, such as Acanthostega gunnari Jarvik, 1952 which had eight in the forelimb (Coates and Clack, 1990) and Ichthyostega Säve-Söderbergh, 1932 with seven digits in the hindlimb (Säve-Söderbergh, 1932; Jarvik,1996). This fact indicates that polydactyly is the plesiomorphic condition for the tetrapod autopodium (Laurin et al., 2000).”
No. That’s a myth. The large reptile tree (LRT, 1713+ taxa; subset Fig. 4) recovered four fingers in basal tetrapods. Five fingers are derived in several convergent clades. More than five fingers occurs only in Acanthostega and kin, a derived clade without descendants. (Maybe Ichthyostega, too, but we have no hands for it).
Figure 3. Metoposaurus manus with five digits from Konietko-Meier et al. 2020. Colors and PILs added here. Note the foreshortening of the distal phalanges somewhat corrected here and in diagram at right. Not sure why p5.1 is so long in the diagram.
From the Konietko-Meier et al. 2020 abstract: “Temnospondyli are commonly believed to have possessed four digits in the manus and five in the pes. However, actual finds of articulated autopodia are extremely rare. The most important observation is the presence of five metacarpals in this specimen. This allows reconstructing the manus as pentadactyl.”
Figure 4. Subset of the LRT focusing on basal tetrapods. Colors indicate number of fingers known. Many taxa do not preserve manual digits.
From the Konietko-Meier et al. introduction: “The first known record of a pentadactyl hand belongs to the Early Carboniferous stegocephalian Casineria kiddi (Paton et al., 1999).”
Chronology does not always mirror phylogeny.Casinerianests as an archosauromorph reptile, off the bottom of the chart (Fig. 4). Many more primitive taxa had only five digits. The Late Devonian reptilomorph, Tulerpeton, had only five fingers, as we learned earlier.
Among temnospondyls in the LRT
(Fig. 4) the derived taxa leaving no descendants, Parotosuchus and Paracyclotosaurus, were illustrated with five fingers. Trematosaurus is known from skull material only. These fifth fingers are appearing de novo, not as reversals.
Proterogyrinus
developed five fingers. Fingers are not preserved in related taxa, none of which left descendants.
Dissorophids
developed five fingers without leaving descendants.
Reptilomorpha,
starting with Utegenia + Seymouriamorpha, developed five fingers and we are their descendants.
The Konietko-Meier et al. chart (their Fig. 4) indicates the outgroup taxon, Greererpeton (Fig. 5; Godfrey 1986, 1989 had five fingers.
This is an error. Only the PhD thesis illustrates fingers and only four are illustrated (Fig. 5). Maybe the five-digit pes was accidentally added to the manus database?
Figure 5. Data for Greererpeton from Godfrey 1986. Only the pes has five digits.
From the Konietko-Meier et al. introduction: “Reconstruction of the evolution of digit reduction of the most basal and post-Devonian stegocephalians is not possible because of the lack of informative fossils. It is known that reductions in the number of digits have occurred frequently during tetrapod evolution, but it is still not known exactly when or even how many times the number of digits was reduced to five or less (Laurin et al., 2000).”
The LRT clarifies this problem. Reductions in the number of digits occurred less frequently than envisioned by Konietko-Meier et al. since ‘four fingers’ is the primitive and plesiomorphic condition, even in Greererpeton.
References Godfrey SJ 1989. The postcranial skeletal anatomy of the Carboniferous tetrapod Greererpeton burkemorani Romer, 1969. Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences, 323(1213), 75–133. Konietzko-Meier D, Teschner EM, Bodzioch A and Sander PM 2020. Pentadactyl manus of the Metoposaurus krasiejowensis from the Late Triassic of Poland, the first record of pentadactyly among Temnospondyli. Journal of Anatomy 00:1–11. DOI: 10.1111/joa.13276
Updated August 12, 2020 with a new figure 3 which shows the new position of the quadratojugal repaired in figure 2. Apologies for the oversight.
In summary: Miedema et al. 2020 decided not to include a phylogenetic analysis (e.g. Fig. 1) and so make several mistakes as they describe a µCT scanned specimen (Fig. 2, 3) that turned out to be not quite Macrocnemus (Fig. 1), even though it looks just like one.
Figure 1. Subset of the LRT with the addition of the PIMUZ 2477 specimen.
Worse yet,
Miedema et al. 2020 promoted a traditional myth, that tanystropheids, like Macrocnemus, were archosauromorphs without testing lepidosaurs. The LRT tests both clades and Macrocnemus nests with lepidosaurs like Huehuecuetzpalli (Fig. 3) despite sharing many convergent traits with the very similar (by convergence) archosauromorph, Prolacerta.
Figure 2. The PIMUZ T 2477 specimen wrongly traditionally assigned to Macrocnemus. Some corrections and repairs noted. The left maxilla tracing does not match the left maxilla µCT scan.
The palate was restored differently here
than in Miedema et al. 2020 (Fig. 2). So was the prefrontal.
Figure 3. Several Macrocnemus specimens to scale alongside the ancestral taxon in the LRT, Huehuecuetzpalli, and descendant taxa in the LRT, including Cosesaurus and the fenestrasaurs Sharovipteryx, Longisquama and Bergamodactylus. The similarities in transitional taxa should be obvious.
Epipterygoid “An elongate rod-like element is present underneath the basioccipital and parabasisphenoid in PIMUZ T 2477 (confirming earlier findings here). In this constellation, the rod-like part of the element extends dorsally along the anterior part of the prootic as in all extant Squamata.”
We looked at epipterygoids found in tritosaurs earlier here.
Ontogenetic stage of PIMUZ T 2477 “The smallest specimen, and so far, the only specimen considered a juvenile, MSNM BES SC 111, is slightly smaller in cranial length than PIMUZ T 2477 (ca. 38 mm and ca. 42 mm respectively).”
Not true. Phylogenetic analysis indicates no juveniles are known, only small adults. The BES SC 111 specimen is close to even smaller langobardisaurs, cosesaurs and pterosaurs.
“Juvenile specimens have relatively larger orbits and relatively larger crania compared to adults.”
Not true. Several tritosaurs known from juveniles and adults demonstrate isometric growth.
It is so important to start your study
with a phylogenetic analysis. Lacking an analysis Miedema et al. had no idea that
their specimen did not nest with Macrocnemus
their specimen was closer to Dinocephalosaurus
that all such taxa were lepidosaurs (Peters 2007) in a new clade, the Tritosauria
that no tanystropheids were archosauromorphs
that no known Macrocnemus specimens were juveniles
These are the traditional problems
that come from students following their traditional professors and traditional textbooks, rather than finding out for themselves using phylogenetic analysis. Testing all the specimens as individual taxa is so important as we learned earlier regarding Dorygnathus, Rhamphorhynchus, Pteranodon and many other pterosaurs.
Once again the curse of Chris Bennett
ripples out. Several years ago a rejected paper on the Tritosauria (online at Researchgate.net) could have been cited, but Chris Bennett once told me, “You will never be published, and if you are published, you will not be cited.”
Postscript:
In March 2020 O’Connor et al. produced a specimen, Oculudentavis, they promoted as an archosauromorph that turned out to be a lepidosaur. This week, under great pressure, the authors retracted their paper. The Miedema authors published the EXACT SAME mistake. Will Miedema et al. have to retract their paper, too? I doubt it. This was not a cover story and there will not be the same sort of pressure on this taxon.
References Li C, Rieppel O and LaBarbera MC 2004. A Triassic aquatic protorosaur with an extremely long neck. Science 305:1931. Li Z, Wang W, Hu H, Wang M, Y H and Lu J 2020. Is Oculudentavis a bird or even archosaur? bioRxiv (preprint) doi: https://doi.org/10.1101/2020.03.16.993949 Miedema F, Spiekman1 SNF, Fernandez V, Reumer JWF AND Scheyer1 TM 2020. Cranial morphologyof the tanystropheid Macrocnemus bassanii unveiled using synchrotron microtomography. Nature.com/scientificreports (2020) 10:12412. https://doi.org/10.1038/s41598-020-68912-4 Peters D 2007. The origin and radiation of the Pterosauria. In D. Hone ed. Flugsaurier. The Wellnhofer pterosaur meeting, 2007, Munich, Germany. p. 27. Peyer B 1937. Die Triasfauna der Tessiner Kalkalpen, XII. Macrocnemus bassanii Nopcsa. Abh. Der Schweizierischen Palaeontologischen Gesellschaft LIX (1937). Xing L, O’Connor JK,; Schmitz L, Chiappe LM, McKellar RC, Yi Q and Li G 2020. Hummingbird-sized dinosaur from the Cretaceous period of Myanmar. Nature. 579 (7798): 245–249.
Several taxa tested in the large reptile tree (LRT, 1710+ taxa; subset Fig. 2) do not remain in the LRT or the MacClade file forever. Typically they are known from very few parts, like a single jawbone. These bits and pieces enter the LRT to see where they nest, and then they exit.
In this case, Redondavenator quayensis(Nesbitt et al. 2005; Fig. 1; NMMNH P-25615) is known from a partial snout, a partial coracoid and a partial scapula.
Figure 1. Redondavenator (NMMNH P-25615) snout from Nesbitt et al. 2005 and colored here.
According to the abstract “Its exact phylogenetic position [within Crocodylomorpha] could not be determined from the preserved material, but key characters suggest a phylogenetic position near the base of Sphenosuchia.”
According to the Systematic Position section: “Redondavenator displays the following two sphenosuchian characters: reduced external naris and nasal is not bifurcated (no descending process).
According to the Palecology section: “the complete skull of Redondavenator is estimated to be at least 60 cm long.” That’s six to eight times larger than in sister taxa. “Anterior sculpturing[of the snout elements] has been correlated with semi-aquatic habits as an osteological correlate of dome pressure receptors that sense motion and help orientate the animal in water.” And that may explain the size difference.
Figure 2. Subset of the LRT focusing on Crocodylomorpha. Matching Nesbitt et al. 2005, the LRT nests Redondavenator near the base of the Crocodylomorpha, but several nodes away from Sphenosuchia.
Figure 2. Images from Wu et al. 1993, colors and hind limbs added. Compare to skull in figure 1.
The Wikipedia page on Sphenosuchia does not include
several of the taxa recovered here at the base of the Crocodylomorpha, including Pseudhesperosuchusand Lewisuchus, taxa that nest on either side of Redondavenator here (Fig. 2). Redondavenator nests close to Dibothrosuchus, but lacks the accessory fenestra between the premaxilla and maxilla, as noted by Nesbitt et al. 2005.
Figure 5. Skull of Pseudhesperosuchus, a basal bipedal crocodylomorph close to Carnufex.
It is important to know where taxa nest, but if a snout specimen nests close to a post-crania specimen in the LRT, then loss of resolution will result. That is why Redondavenator will not remain within the MacClade file or the LRT. Testing has already indicated its correct node and that node agrees with the original nesting.
Thanks to Dr. Lucas for sending a PDF.
References Nesbitt SJ, Irmis RB, Lucas SG and Hunt AP 2005. A giant crocodylomorph from the Upper Triassic of New Mexico. – Paläontologische Zeitschrift 79(4): 471–478, 4 figs., Stuttgart, 31. 12. 2005.
Yesterday we updated an online evogram produced by the University of California – Berkeley under the tutelage of Professor Emeritus Kevin Padian. Today a few remaining evograms get similar updates.
Figure 1. Evogram from the Berkeley website focusing on bird origins.
The Berkeley evogram on bird origins (Fig. 1) closely matches that of the large reptile tree (LRT, 1710+ taxa). Only two corrections include: Eoraptoris a basal phytodinosaur, not a theropod. The caption on tyrannosauroids is, “Reduction of III“, but the illustration does not show a reduction of digit 3.
Figure 2. Evogram from the Berkeley website focusing on mammal origins.
The Berkeley evogram on mammal origins (Fig. 2) mistakenly puts Yanaconodon close to eutherians. By contrast the LRT nests Yanaconodon in a pre-mammal clade. There is no need to add the highly derived Dimetrodon to a pre-mammal cladogram. It left no descendants. Haptodus is a more primitive, more plesiomorphic choice here. We are its descendants. Likewise, the platypus (Ornithorhynchus) is also highly derived. Better to put a basal prototherian, like Sinodelphys or Megazostrodon, in its place. We are their descendants. Duckbilled platypusses are not plesiomorphic nor ancestral to any other mammal.
Figure 3. Evogram from the Berkeley website focusing on tetrapod origins. This is similar to an evogram found in Padian 2013.
The Berkeley evogram on tetrapod origins (Fig. 3) includes Eusthenopteron, which left no descendants in the LRT. Flatter Cabonnichthys is a better ancestor. Flattened Tiktaalik and Panderichthys switch places here. The latter has four proto-fingers. Ichthyostega and Acanthostega have supernumerary digits and leave no descendants in the LRT. Here flatter basal tetrapods, like Greererpeton, have a skull, body, limbs and fingers more like those of Panderichthys. Dendrerpeton has a shorter torso and longer limbs. Even more so does Gephyrostegus. The loss of lumbar ribs makes room for more and larger amniotic eggs. Contrary to its original description, Tulerpeton does not have supernumerary digits. Gephyrostegus is a more completely known representative reptilomorph. Rather than make the huge morphological jump to Homo, represented here (Fig. 3) by Darwin himself, another living reptile, Iguana, enters the evogram with fewer changes to distinguish it from Gephyrostegus. Smaller steps mark the gradual progress of evolution. Big jumps, like adding Darwin (even as a joke), throw the whole concept into a tizzy. A similar evogram was published in Padian 2013, a paper ironically entitled, “Correcting some common misrepresentations of evolution in textbooks and the media.”
By minimizing taxon exclusion the LRT does not make the mistakes shown above (Figs. 1-3) in the Berkeley evograms. Due to its large taxon list, the LRT more clearly documents the gradual accumulation of traits that characterizes every evolving vertebrate, and it does so while testing all competing candidates.
Let Kevin Padian at Berkeley know:
It’s time to update those online evograms!
This just in An email from Anna Thanukos at the UC Museum of Paleontology, “Hi David, Thanks for your interest in our site. I wanted to let you know that the material on the page of interest has recently been reviewed by a curator at the Smithsonian and will be updated in a website revamp we are currently developing. Best regards, Anna Thanukos, UC Museum of Paleontology.”
References Padian K 2013. Correcting some common misrepresentations of evolution in textbooks and the media. Evolution Education and Outreach 6: 1-13.
Professor Kevin Padian (U of California, Berkeley) has been a champion for evolution over the past several decades. In the 1980s I became acquainted with him when he was the science expert for my first book, Giants.
The following one hour video on YouTube caught my eye.
Professor Padian brilliantly discusses how school districts dealt with invading Creationists. Padian has been leading the charge on many fronts regarding evolution. Unfortunately, he has stayed in his tent sipping tea regarding the origin of flight in pterosaurs (Padian 1985), and the origin of whales, as you’ll see below.
From the Berkeley.edu page on pterosaur flight: “Pterosaurs are thought to be derived from a bipedal, cursorial (running) archosaur similar to Scleromochlus in the late Triassic period (about 225 million years ago). Other phylogenetic hypotheses have been proposed, but not in the context of flight origins. The early history of pterosaurs is not yet fully understood because of their poor fossil record in the Triassic period. We can infer that the origin of flight in pterosaurs fits the “ground up” evolutionary scenario, supported by the fact that pterosaurs had no evident arboreal adaptations. Some researchers have proposed that the first pterosaurs were bipedal or quadrupedal arboreal gliders, but these hypotheses do not incorporate a robust phylogenetic and functional basis. The issue is not yet closed.”
This comes 20 years afterLangobardisaurus, Cosesaurus, Sharovipteryx and Longisquama (Fig. 1) were added to four previously published phylogenetic analyses and all nested closer to pterosaurs than any tested archosaur (Peters 2000). Aspects of this topic were reviewed here in 2011 and here in 2015.
Figure 2. Click to enlarge. The origin of the pterosaur wing from Huehuecuetzpalli (B) to Cosesaurus (C) to Sharovipteryx (D) to Longisquama (E) to the basal pterosaur, Bergamodactylus (F and G).
The same webpage notes: “Pterosaurs also had a bone unique to their clade. It is called the pteroid bone, and it pointed from the pterosaur’s wrist towards the shoulder, supporting part of the wing membrane. Such a novel structure is rare among vertebrates, and noteworthy; new bones are unusual structures to evolve — evolution usually co-opts bones from old functions and structures to new functions and structures rather than “reinventing the wheel.”
This comes 11 years after Peters 2009 showed the pteroid was not unique, but a centralia that had migratred medially in Cosesaurus (like the panda’s ‘thumb’). Likewise, the not-so-unique pteroid was co-opted from old functions, contra the Berkeley evolution page.
The same webpage notes: “Pterosaurs had other morphological adaptations for flight, such as a keeled sternum for the attachment of flight muscles, a short and stout humerus (the first arm bone), and hollow but strong limb and skull bones.”
We’ve known since Wild 1993 that what Padian 1985 called a keeled sternum is actually a sternal complex composed of a fused interclavicle + clavicle + single lepidosaur sternum (Fig. 3) after migration over the interclavicle.
Figure 3. Tritosaur pectoral girdles demonstrating the evolution and migration of the sternal elements to produce a sternal complex.
Backstory…
25 years ago, when I first met Kevin Padian and Chris Bennett, they both impressed upon me, at the same time and during a single conversation, the need for a proper phylogenetic context before making any sort of paleontological hypothesis. That’s when MacClade and PAUP were still ‘newish’. That’s why you might find it ironic that neither Padian nor Bennett have ever tested the addition of the four key taxa in figure 3 to prior published analyses that included pterosaurs, as I did in Peters 2000.
On the second topic of whale evolution:
Padian’s ‘evogram’ (evolution diagram) simply lacks a few key taxa. Odontocetes don’t arise from hippos. Only mysticetes do. Here (Fig. 4) a few missing transitional taxa are added to the existing evogram. Likewise the outgroup for Pakicetus and Indohyus now include overlooked tenrecs and leptictids. They look more like Indohyus than the hippo because microevolution becomes more apparent when pertinent taxa are added. Otherwise it’s a big morphological jump from hippos to Indohyus. Adding taxa makes ‘the jump’ much smaller as the LRT has demonstrated dozens of times. No one should be afraid to simply add taxa.
Figure 4. Whale evogram from Berkeley website and what happens when you add taxa based on the LRT. Two frames change every 5 seconds. It’s not good that the outgroup to the slender Indohyus is the massive Hippopotamus. Frame two repairs that inconsistency with a little microevolution.
As you can see, the University of California at Berkeley no longer stands at the vanguard of paleontology. Rather it has been promoting traditional myths on its website for the last twenty years.
According to Padian’s online talk (above): “Just because you have a degree in science does not mean you’re a scientist. Scientists are people who do research, publish peer-reviewed research as a main part of their living.”
That’s good to know. Of course, it doesn’t help if one suffers from the curse of Cassandra. On that point, I’m not asking anyone to ‘believe the LRT’, but to simply add taxa to your own favorite cladograms, as Peters 2000 did to four different previously published studies that each had their own taxon and character lists. That’s what the large reptile tree has continued to do over the last 9 years. Others who have added taxa and recovered results confirming those recovered by the LRT are listed here. The pair of PhDs who decided those results should be erased are listed here.
Ingroup scientists who attempt to exclude outgroup scientists is a common thread in human history. Here’s a YouTube video trailer for an upcoming Marie Curie biography. I’m sure you all know the story of her pioneering work in radioactive elements.
References Padian K 1985. The origins and aerodynamics of flight in extinct vertebrates. Palaeontology 28(3):413–433. Peters D 1989. Giants of Land, Sea and Air — Past and Present. Alfred A. Knopf/Sierra Club Books 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 2009. A reinterpretation of pteroid articulation in pterosaurs. Journal of Vertebrate Paleontology 29: 1327-133. Wild R 1993. A juvenile specimen of Eudimorphodon ranzii Zambelli (Reptilia, Pterosauria) from the upper Triassic (Norian) of Bergamo. Rivisita Museo Civico di Scienze Naturali “E. Caffi” Bergamo 16: 95–120.
Today: Some short YouTube museum tour videos without narration and two bonus videos on continental drift and on becoming a PhD.
1 Wyoming Dinosaur Center at Thermoplis:
2 San Antonio Museum in Texas:
3 American Museum of Natural History in New York:
4 Field Museum in Chicago:
Bonus video #1 the best I’ve seen on the history of continental drift:
Bonus video #2 A young man on TEDx discusses the ups and downs of PhD students.
Given these strict parameters, high expenses and meager, postponed rewards,
it’s no wonder why so many PhDs and PhD candidates dismiss and attempt to suppress published and unpublished work by enthusiastic outsiders without a science degree. They must see ReptileEvolution.com as taking an academic short-cut. Not paying the price. Not doing it the ‘right’ (= traditional) way.
By contrast I see ReptileEvolution.com as a retirement project. Every day I simply add taxa to a growing phylogenetic analysis. Sadly, no one with a PhD, worse yet: no one else on the planet, has wanted to do this for the last nine years. So, at present, there is no competing analysis with a similar taxon list. Given that the typical PhD project can last for two to eight years, a competing cladogram would make a great PhD project!
The Pterosaur Heresies 