Turtles and pterosaurs tested again, nine years later with 1300 more taxa

In 2011,
back when the large reptile tree (LRT, 1786+ taxa) was much smaller (only about 400 taxa) I attempted a rather odd test. I wondered if turtles and pterosaurs (both Lepidosauromorpha in the LRT) would nest together while playing taxon deletion games. Here’s the 2011 link:

https://pterosaurheresies.wordpress.com/2011/07/25/pterosaurs-and-turtles-say-it-aint-so/

Click here to see those 2011 turtle-pterosaur results, still posted online.

Other workers interested in pterosaurs
(most recently Ezcurra et al. 2020) also like to play taxon deletion games as they attempt to cherry-pick preferred sisters close to dinosaurs while omitting tested and validate sisters far from dinosaurs.

The backstory
Peters 2000 added four tritosaur tanystropheid, fenestrasaur pterosaur precursors, Langobardisaurus, Cosesaurus, Sharovipteryx, and Longisquama (Fig. 1) to four previously published analyses and in every case these four nested closer to pterosaurs than any archosaur, archosauriform or archosauromorph. Unfortunately those taxa were omitted from more recent analysis, like those of Kellner 2003, Unwin 2003, Hone and Benton 2007, 2008, Bennett 2012 and Ezcurra et al. 2020.

A few years later, but still 14 years ago,
Peters 2007 added the lepidosaur, Huehuecuertzpalli and it attracted the four fenestrasaurs + pterosaurs. The LRT nested turtles within the Lepidosauromorpha here in 2011, updated here in 2014.

Now that many more taxa are present in the LRT,
let’s rerun that test and its various deletion subunits.

Today, in 2020, repeating the experiment with more taxa
deleting all lepidosauromorphs, other than turtles (and their ancestors back to Stephanospondylus) and pterosaurs, and keeping all archosauromorphs and enaliosaurs. Outgroups retained = Gephyrostegus and Silvanerpeton.

Results: Pterosaurs nest with turtles and basal sea reptiles rather than archosaurs and archosauromorphs.

Adding back all basal diapsids and protosaurs

Results: Basal diapsids as the first large clade, followed by protorosaurs with tritosaurs based on the convergence found there.

Adding back all tritosaurs
(= Macrocnemus as the last common ancestor) nests turtles and pareiasaurs as the first large clade, tritosaurs (including pterosaurs) as the next large clade, followed by archosauromorophs (including Lagerpeton and Scleromochlus).

Figure 1. Squamates, tritosaurs and fenestrasaurs in the phylogenetic lineage preceding the origin of the Pterosauria.

Deleting all non-fenestrasaur tritosaurs
(= Cosesaurus as the last common ancestor)

Results: Fenestrasaurs nest with basal diapsids. Orovenator is the proximal outgroup.

Deleting all non-pterosaur fenestrasaurs
(Bergamodactylus as the last common ancestor).

Results: Pterosaurs nest between turtles and choristoderes.

Figure 2. Basal diasids and proto-diapsids. Largely ignored these putative synapsids actually split from other synapsids while retaining the temporal fenestra trait that serves as the basis for the addition of upper temporal fenestra in diapsids. Included here are Protorothyris, Archaeovenator, Mycterosaurus, Heleosaurus, Mesenosaurus, Broomia, Milleropsis, Eudibamus, Petrolacosaurus, Spinoaequalis, and Tangasaurus.

Deleting all basal diapsids
(only turtles, pterosaurs and archosauromorphs are ingroup taxa).

Results: Pterosaurs nest between turtles and choristoderes, far from Scleromochlus, dinosaurs and Lagerpeton.

Deleting all turtle ancestors 
(= deleting Stephanospondylus through pareiasaurs)

Results: Pterosaurs nest between turtles and choristoderes, far from Scleromochlus, dinosaurs and Lagerpeton.

Figure 3. Faxinalipterus matched to Scleromochlus. The former is more primitive, like Gracilisuchus, in having shorter hind limbs and more robust fore limbs. The maxilla with fenestra and fossa, plus the teeth, are a good match.

Re-inserting terrestrial younginiforms and protorosaurs
to this last taxon list.

Results: Two large clades follow the turtle clade. Pterosaurs nest between three basal Youngina specimens and the clade Protorosauria, apart from the terrestrial younginiformes (other Youngina specimens + Pararchosauriformes (= Proterosuchus as the last common ancestor and choristoderes) and Euarchosauriformes (= Euparkeria as the last common ancestor and Lagerpeton and Scleromochlus).

Figure 4. The closest kin of Tropidosuchus are the much larger Chanaresuchus (matching Nesbitt 2011) and the smaller Lagerpeton.

Bottom line:
With or without tritosaurs and fenestrasaurs, pterosaurs prefer to nest with terrestrial younginiforms, choristoderes or turtles rather than lagerpetids, dinosaurs or Scleromochlus. Taxon exclusion remains the problem in traditional cladograms (like the recent Ezcurra et al. 2020).

Please send this post to anyone who still believes or protects
the outmoded clades ‘Ornithodira’ or ‘Avemetatarsalia’. Too many professors and their students are clinging to invalidated myths based on taxon exclusion — which is not what real scientists do. Real scientists test all competing candidates without cherry-picking or omitting taxa to suit their personal whims and traditions, in fear of their professors or colleagues.

If you would like to play taxon deletion games with the LRT,
click here, then click on the yellow CLICK HERE for LRT MacClade.nex file box with your request.

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References
Bennett SC 1996. The phylogenetic position of the Pterosauria within the Archosauromorpha. Zoological Journal of the Linnean Society 118:261-308.
Bennett SC 2012. The phylogenetic position of the Pterosauria within the Archosauromorpha re-examined. Historical Biology. iFirst article, 2012, 1–19.
Benton MJ 1983. The Triassic reptile Hyperodapedon from Elgin, functional morphology and relationships. Philosophical Transactions of the Royal Society of London, Series B, 302, 605-717.
Brusatte SL , Benton MJ , Desojo JB and Langer MC 2010. The higher-level phylogeny of Archosauria (Tetrapoda: Diapsida), Journal of Systematic Palaeontology, 8:1, 3-47.
Evans SE 1988. The early history and relationships of the Diapsida. In: M. J. BENTON (Ed.), The Phylogeny and Classificationof the Tetrapoda. 1. Amphibians, Reptiles, Birds. Systematics Symposium Association Special Volume; Oxford (Clarendon Press), 221–260.
Ezcurra MD et al. (17 co-authors) 2020. Enigmatic dinosaur precursors bridge the gap to the origin of Pterosauria. Nature (2020). https://doi.org/10.1038/s41586-020-3011-4
Hone DWE and Benton MJ 2007. An evaluation of the phylogenetic relationships of the pterosaurs to the archosauromorph reptiles. Journal of Systematic Palaeontology 5:465–469.
Hone DWE and Benton MJ 2008. Contrasting supertree and total evidence methods: the origin of the pterosaurs. Zitteliana B28:35–60.
Jalil N-E 1997. A new prolacertiform diapsid from the Triassic of North Africa and the interrelationships of the Prolacertiformes. Journal of Vertebrate Paleontology 17(3), 506-525.
Kellner AWA 2003. Pterosaur phylogeny and comments on the evolutionary history of the group. Geological Society Special Publications 217: 105-137.
Nesbitt SJ 2011. The early evolution of archosaurs: relationships and the origin of major clades. Bulletin of the American Museum of Natural History 352: 292 pp.
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 2000. A Redescription of Four Prolacertiform Genera and Implications for Pterosaur Phylogenesis. Rivista Italiana di Paleontologia e Stratigrafia 106 (3): 293–336.
Peters D 2007. The origin and radiation of the Pterosauria. In D. Hone ed. Flugsaurier. The Wellnhofer pterosaur meeting, 2007, Munich, Germany. p. 27.
Sereno PC 1991. Basal archosaurs: phylogenetic relationships and functional implications. Journal of Vertebrate Paleontology 11 (Supplement) Memoire 2: 1–53.
Unwin DM 2003. On the phylogeny and evolutionary history of pterosaurs. Pp. 139-190. in Buffetaut, E. & Mazin, J.-M., (eds.) (2003). Evolution and Palaeobiology of Pterosaurs. Geological Society of London, Special Publications 217, London, 1-347.

https://pterosaurheresies.wordpress.com/2012/09/27/bennett-2012-still-barking-up-the-wrong-pterosaur-tree/

https://pterosaurheresies.wordpress.com/2020/12/10/new-pterosaur-precursor-study-excludes-all-pterosaur-precursors/

https://pterosaurheresies.wordpress.com/2012/04/13/a-supertree-of-pterosaur-origins-hone-and-benton-2007-2009/

New pterosaur precursor study excludes all pterosaur precursors

Summary, for those in a hurry:
Ezcurra et al. 2020 create a chimaera from lagerpetid and protorosaur bits and pieces, then call it a pterosaur precursor close to dinosaurs. Unfortunately, this paper is another taxon omission disaster from Nature.

It is good to see more material data
appearing for lagerpetids (Figs. 4, 13), an enigmatic clade formerly known from pelvic and hind limb material, and more recently from skull bits.

Unfortunately
Ezcurra et al. follow an established history of workers omitting competing taxa in pterosaur origin papers while cherry-picking comparative taxa and employing a chimaera of disassociated and unrelated bits and pieces from a protorosaur and a lagerpetid. By contrast, the omitted pterosaur precursors are complete, articulated, preserve soft tissue and nest closer to pterosaurs in several prior cladograms.

Figure 1. From Ezcurra et al. 2020 showing the various parts used to produce the chimaera in the middle and call it a pterosaur precursor. See Figure 2. for a valid pterosaur precursor.

Ezcurra et al. posit a pterosaur relationship
after omitting four competing candidate taxa put forth twenty years ago in Peters 2000.

In 2000 the four competing taxa
(Langobardisaurus, Cosesaurus (Fig. 2), Sharovipteryx, Longisquama) where added to four prior phylogenetic analyses and all nested closer to pterosaurs than any prior candidates. The most basal pterosaur, Bergamodactylus (MPUM 6009, Fig. 6), is also omitted from the Ezcurra et al. study.

Figure 2.  CLICK TO ENLARGE. Cosesaurus reconstructed with enlarged parts of interest including a pes (foot) matching a Rotodactylus track. Here the pelvis is reconstructed according to figure 3. Shown here about life-size.

Ezcurra et al. take a moment to cite Peters 2000,
but in a misleading fashion: “However, some studies have alternatively recovered pterosaurs as the sister group … among tanystropheid archosauromorphs.”

Not archosauromorphs, “fenestrasaurs.” Peters 2007 moved them all over to Lepidosauria.

All four fenestrasaurs have an elongated pedal digit
with two phalanges longer than the metatarsal, matching basal pterosaurs. A long pedal digit 5 is not found in the new lagerpetid/protorosaur chimaera (Fig. 13).

Figure 3. Click to enlarge. The origin of the pterosaur wing and whatever became of manual digit 5?

Manus
Cosesaurus, Sharovipteryx and Longsquama have a robust, elongated manual digit 4 on a robust metacarpal 4 rotated axially. The finger frames the wing membrane in pterosaurs. By contrast, metacarpal 4 is short and not robust in the new lagerpetid/protorosaur (Fig. 4).

Figure 4. The lagerpetid manus compared to the basal pterosaur manus. In the lagerpetid metacarpal 4 is not larger or more robust than the others. Cosesaurus likewise has metacarpals of similar diameter, but metacarpal 1 is not shorter than the others. Sharovipteryx and Longsquama have a transitional manus, including the evolutionary shortening of metacarpal 1, as in Bergamodactylus. So this trait is convergent in a valid phylogenetic context. Compare to figure 3.

Coracoid
Cosesaurus, Sharovipteryx and Longisquama have a quadrant-shaped, locked down coracoid (Figs. 2, 5). Such a shape is also found in birds and pterosaurs. This enables flapping. The authors reconstruct the new lagerpetid/protorosaur chimaera with a mobile disc-like coracoid.

Figure 5. Click for rollover image. Colorized sternal complex elements in Cosesaurus. Coracoids in blue. Scapulae in green. Clavicles in pink. Interclavicle in red. Sternum in yellow. Reconstructed in figure 2.

Sternal complex
In Cosesaurus and Longsiquama the ventral stem of the immobile coracoid articulates with a broad sternal complex (Fig. 5) created by the migration and overlapping of robust clavicles, a single lepidosaurian sternum, and a cruciform interclavicle that are fused together in Longisquama and pterosaurs. The new lagerpetid/protorosaur chimaera has no such sternal complex.

Prepubis
Cosesaurus has a prepubis (Fig. 2), a pelvic bone found otherwise only in pterosaurs (Fig. 6). A prepubis is not found in the new lagerpetid/protorosaur chimaera.

Elongate ilium and expanded sacrum
Cosesaurus, Sharovipteryx and Longisquama have an elongate ilium, matching pterosaurs, with a much longer preacetabular process than the new chimaera. The Cosesaurus sacrum, includes four vertebrae articulating with the medial ilium. Sharovipteryx, Longisquama and the basal pterosaur, Bergamodactylus, have more sacrals between longer ilia. The new lagerpetid/protorosaur chimaera has two sacrals. More than two sacrals is common in bipedal taxa.

Figure 6. Bergamodactylus compared to Cosesaurus. Hypothetical hatchling also shown.

Attenuated tail
The tail of Cosesaurus, Sharovipteryx and pterosaurs is attenuated with tiny chevrons because the tail no longer anchors large caudofemoralis muscles. Such an attenuated tail is not present on the new lagerpetid/protorosaur chimaera, which as deep chevrons.

Pteroid
Peters 2009 documented the migration of two centrale on the wrist of Cosesaurus to the medial rim where they match the pteroid and prearticular carpal in pterosaurs.

Antorbital fenestra
The new lagerpetid/protorosaur chimaera has an antorbital fenestra without a fossa extending to the naris. All archosauriformes, some protorosaurs, all pterosaurs, and the competing candidates also have this trait. The antorbital fenestra is not close to the naris in Tropidosuchus, and is unknown in the holotype Lagerpeton.

Figure 7. New mandible compared to the Triassic pterosaur Seazzadactylus where the tip is actually a tooth as in Langobardisaurus.

Figure 8. Pterosaur precursor, Langobardisaurus, has anteriorly-oriented dentary tip teeth as  in basal pterosaurs.

Mandible
The new lagerpetid/protorosaur chimaera mandible has an ‘edentulous and tapering anterior end’ (Fig. 7. The basalmost pterosaur, Bergamodactylus, has teeth at the tip of its mandible. So does the pterosaur employed by Ezcurra et al. (Seazzadactylus, Fig. 8). So does Langobardisaurus (Fig. 8), nesting outside the Pterosauria.

Figure 9. From Ezcurra et al. 2020 comparing skull top of Ixtalerpeton to Prolacerta, not close to lagerpetids. Here the pink Kongonaphon rostrum fragment is matched to the Ixalerpeton cranium.

Femur
Lagerpetid and protorosaur femora have a large trochanter for the insertion of large caudofemoralis muscles. Pterosaurs and the four fenestrasaurs lack a large trochanter because the caudofemoralis has become a vestige and is lost in pterosaurs. The great majority of the femoral muscles in pterosaurs and fenestrasaurs anchor on the pelvis and prepubis instead of the tail.

Figure 10. Ixalerpeton pelvis compared to Prolacerta.

Deltopectoral crest on humerus
The new lagerpetid/protorosaur chimaera has a long, low deltopectoral crest. Sharovipteryx and Longisquama each have a large, robust deltopectoral crest, as in pterosaurs.

Figure 11 The closest kin of Tropidosuchus are the much larger Chanaresuchus (matching Nesbitt 2011) and the smaller Lagerpeton.

In their study on pterosaur origins,
Ezcurra et al. also omitted a pair of citations of a single supertree study by Hone and Benton (2007, 2008). In the first paper, Hone and Benton announced they would test the taxa in Peters 2000 against those in Bennett 1996. In the second paper Hone and Benton omitted all taxa from Peters 2000, omitted any citation of Peters 2000, then credited both competing hypotheses to Bennett 1996. This is a glaring example of the established history of omitting pertinent and competing taxa in pterosaur origin papers. Dozens of other papers simply omit competing candidates from Peters 2000. Most of them do so without making the mistake of promising in print to include them as part of a study.

Figure 12. The lagerpetid maxilla associated with the lagerpetid foot in figure 13. Kongonaphon restoration based on Tropidosuchus.

Figure 13. Tracing of lagerpetid pes with colors showing all four toes. Digits 1 and 2 are fused to metatarsal 3. Only digits 3 and 4 bore weight. Digit 5 was a vestige unlike basal pterosaurs.

To combat that long history of omitting taxa,
www.ReptileEvolution.com tests 1775 taxa in a single phylogenetic analysis that includes lagerpetids, protorosaurs, dinosaurs and pterosaurs. In that wide gamut online study, lagerpetids nest with Tropidosuchus and the Chanaresuchidae. Pterosaurs nest with the four fenestrasaurs within a third clade of lepidosaurs, the Tritosauria, far from dinosaurs, protorosaurs and lagerpetids. Chimaera taxa (created from bits of this and parts of that) are not tested..for good reason. There is no cherry-picking here. Taxa nest wherever the software indicates they should.

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References
Ezcurra MD et al. (17 co-authors) 2020. Enigmatic dinosaur precursors bridge the gap to the origin of Pterosauria. Nature (2020). https://doi.org/10.1038/s41586-020-3011-4
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 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

Cosesaurus paper on ResearchGate.net

http://reptileevolution.com/cosesaurus.htm
http://reptileevolution.com/pterosaur-wings.htm
http://reptileevolution.com/langobardisaurus.htm
http://reptileevolution.com/cosesaurus.htm
http://reptileevolution.com/sharovipteryx.htm
http://reptileevolution.com/longisquama.htm
http://reptileevolution.com/MPUM6009.htm
Review in Nature by Kevin Padian https://doi.org/10.1038/d41586-020-03420-z

Here’s the quote from Gizmodo.com that says it all:
“These creatures seem an unlikely sister group from which pterosaurs emerged, which is probably why they’ve been ignored for so long.”

Hone 2020 reviews anurognathid pterosaurs

Here’s a new paper from Dr. DWE Hone (2020).
Quoting Hone’s own publicity sheet regarding the paper, “there’s not a huge amount to talk about here since as it’s a review, it doesn’t contain too much that’s new.”

Even so,
Hone manages to promote invalid pterosaur myths, like the pushup-takeoff (Fig. 1) and the presence of a giant eyeball in the front of the skull (Bennett 2007, Fig. 1). That was repaired here and here (Fig. 1) several years ago. The purported scleral (eyeball) ring is in fact the maxilla in the smaller flat-head SMNS 81928 specimen (Fig. 1) incorrectly referred to the genus Anurognathus (Figs. 3a, b) by Bennett 2007 and repeated by Hone 2020. Correcting the eyeball problem resulted in a traditional dimorphodontid/ anurognathid-type skull (Fig. 1 top figures) despite the skull being flatter than tall, a morphology repeated several times in later anurognathid discoveries.

Bennett presented a unique morphology
(not shared with any other pterosaur) that was copied and embraced by Witton and Hone without question. Both PhDs should have done their own scientific research instead of trusting anyone under this simple rule: “Extraordinary claims require ordinary evidence.” Yes, ordinary evidence. Just confirm or refute Bennett’s bizarre observation with your own tracing of the specimen and compare that with other similar taxa. That’s what PhDs are paid to do. To trust unique claims like Bennett 2007 without a second examination is not scientific.

Figure 1. The SMNS 81928 anurognathid specimen, two interpretations shown slightly larger than life size. This was the first of several ‘flathead’ anurognathids to be discovered. Let’s hope the blue one can open its wings and start flapping before the eventual face plant. And how did such a take-off configuration evolve from bipedal ancestors?

In summary, Hone 2020
reviews the history of anurognathid research and renames a specimen. Hone promotes previous mistakes (Fig. 1) as valid without support from new, confirming tracings or any tracings whatsoever. Only one taxon is reconstructed (Fig. 1). No phylogenetic analysis appears. The IVPP transitional anurognathid embryo is ignored along with several other basal anurognathids (Fig. 4). Some citations are omitted (see way below). All the above shortcomings and mistakes were resolved online here and at links therein several years ago.

From the Hone 2020 Abstract:
“The anurognathids are an enigmatic and distinctive clade of small, non‐pterodactyloid pterosaurs with an unusual combination of anatomical traits in the head, neck, wings and tail.”

No. After precise tracings and phylogenetic analysis in the large pterosaur tree (LPT, 251 taxa), anurognathids are not enigmas, not all are small, the traditional clade Pterodactyloidea is invalid because it is polyphyletic (Peters 2007, LPT) and there is no reason to trust Hone’s description of the head, neck, wings and tail given his use of M Witton’s invalid illustration (Figs. 1, 2).

Compare Hone and Witton’s published anurognathids
(Figs. 1, 2) with more precise tracings (Figs. 1, 3) of the skeletal and soft-tissue elements of the Anurognathus holotype (Figs. 3a, 3b) distinct from the smaller disc-head SMNS 81928 specimen (Figs. 1, 3b), both from Solnhofen limestones.

Figure 2. From Hone 2020, illustration by M Witton of Anurognathus, not the holotype, but the SMNS 81928 as in figure 1.

Witton and Bennett 9007 place the eyeball over the maxilla
in the large antorbital fenestra, rather than further back in the orbit, as in all other pterosaurs, over the jugal (Fig. 3a cyan), behind the lacrimal (Fig. 3a pink).

Figure 3a. Click to enlarge. DGS tracing of Anurognathus ammonia. Note the placement of the lacrimals in the skull, behind the large antorbital fenestra. That is not the orbit. The small jugal (bright light blue) also indicates the placement of the small orbit in the back half of the skull, as in all other anurognathids. Also note the disappearance of the cervicals beneath the matrix. That may be an embryo by the tail. More on that tomorrow.

Figure 3b. The flat-head pterosaur, a private specimen (on the left) attributed by Bennett (2007) to Anurognathus ammoni (on the right). Pedal digit 5 does not frame a membrane. Rotodactylus and other bipedal Jurassic pterosaur  tracks show how it impresses.

Hone 2020 abstract continues:
“They [anurognathids] are known from very limited remains and few have been described in detail, and as a result, much of their biology remains uncertain.

If pterosaur expert, Dr. Hone, doesn’t want to go to the effort, and wants to ignore workers who have gone to the effort years earlier (Figs. 1-4), before too long Dr. Hone will not be known as the expert he trained to be and thinks he is.

“This is despite their importance as potentially one of the earliest branches of pterosaur evolution or even lying close to the origins of pterodactyloids.

Well, which is it? Basal or transitional? A bit of effort, like creating a cladogram, would have resolved this issue. Hone has a PhD in paleontology. He should not leave things vague and unanswered. This is his passion and his job and he is not doing his job or following his passion.

“This review covers the taxonomy and palaeoecology of the anurognathids, which remain an interesting branch of pterosaurian evolution.”

Hone defined the Anurognathidae,
“as all taxa more closely related to Anurognathus than Dimorphodon, Pterodactylus or Scaphognathus.” That would include all of the taxa (and a few more recent ones) shown in figure 4. Many of these did not appear in the Hone 2020 review, which was intended to be comprehensive.

Figure 4. Click to enlarge. Anurognathids to scale. The adult of the IVPP embryo is 8x the size of the embryo, as in all other tested adult/embryo pairings.

See below for comments
on Hone’s self-published publicity statement, which summarizes his paper and arrived a few days before the PDF became available.

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References
Bennett SC 2007. A second specimen of the pterosaur Anurognathus ammoni. Paläontologische Zeitschrift 81(4):376-398.
Hone DWE 2020. A review of the taxonomy and palaeoecology of the Anurognathidae (Reptilia, Pterosauria). Acta Geologica Sinica (English edition)
https://onlinelibrary.wiley.com/doi/epdf/10.1111/1755-6724.14585?saml_referrer

From DWE Hone’s publication announcement:
“Revising the frog-mouthed pterosaurs: the anurognathids”

Oops. This paper is not a revision. Hone 2020 is titled, “A review of the taxonomy and palaeoecology of the Anurognathidae”. A revision would revise present thinking. Hone himself notes he makes no attempt to do this. Let’s imagine Hone was thinking of the word ‘reviewing’ when he wrote the PR piece, but inserted the more exciting word ‘revising’ by accident.

“The anurognathids are a wonderful group of small non-pterodactyloid pterosaurs known from Europe and various parts of Asia that are perhaps the most distinctive of the early pterosaur groups and probably the latest survivors.

According to the large pterosaur tree (LPT) and simple logic, several clades of Middle and Late Jurassic pterosaurs gave rise to four pterodactyloid-grade clades, some of which extended to the last day of the Cretaceous. You don’t get Cretaceous pterosaurs without Jurassic and Triassic ancestors. Anurognathids also invaded North and South America, according to phylogenetic analysis and footprints.

“They had bizarrely short and broad skulls made of tiny spars of bone and with few teeth and remarkably short tails for non-pterodactyloids. They were mostly small and are interpreted as having been hawking for insect prey on the wing. There are few specimens (even with the recent discoveries) that are hard to tell apart because they are all so similar and yet almost every different specimen has been named as a new species.”

Hone puts no effort (no tracings, a single borrowed reconstruction, no original cladograms) into understanding, reconstructing, modeling, lumping and splitting the several known anurognathid specimens. As in prior studies, Hone stands back when scientific work is required. Hone’s writing is only in service and support to his traditional bias. He avoided citing several peer-reviewed studies that included other anurognathid materials (see below). Bottom line: Hone is supposed to be a scientist, not a journalist. He should be shedding new light on anurognathids, resolving the enigmas, not repeating what others have already published. That’s what journalists do.

“So they are both really unusual and not very well known and that means even if this has taken time to come to fruition, a review of them would be rather handy. And so as you might imagine, this post coincides with a new paper doing exactly that. Somewhat inevitably there’s not a huge amount to talk about here since as it’s a review, it doesn’t contain too much that’s new – the primary role is to bring things together and synthesise them so most of what is there is already known (at least to people who keep up with the pterosaur literature). Reading the review will bring you up speed if you want all the basics, but I do want to talk here about a couple of the more interesting things I have added.”

“The first one is the validity of the various taxa. It’s hardly unknown for pterosaur clades to be made up of lots of species each represented by only a single specimen but the anurognathids are pushing even that. While I can’t immediately think of any calls for synonymy of any taxa, the fact that so few specimens have been described in detail and the poor quality of the preservation of many means that the available lists of diagnoses have been pretty weak to date.

In counterpoint, detailed tracings and reconstructions have been online for every known anurognathid (Fig. 4) for several years. Hone omitted several of these taxa. A cladogram would have helped him separate in-groups from out-groups.

“They are not much better now, but I have at least revised and updated the diagnosis of every taxon. There are two consequences of this that are important. First off, all the current taxa seem valid, and moreover, some of the recently illustrated, but not yet named, specimens also look like they are distinct taxa and there’s probably several new names needed. Secondly, the second species of Dendrorhynchoides, D. mutodongensis is as distinct, if not more so, than many other anurognathid genera and as such needs to be elevated to the genus level… I erected the new genus Luopterus to house the species.

That’s a good name for a specimen needing a new generic name. Well done, Dave!

“Next up, the variation in the different species is quite odd. Anurognathids are weirdly conservative, even compared to other pterosaur groups and while the poor preservation of the specimens hasn’t helped up find distinguishing traits between them, once you sit down and really look it’s hard to find the kinds of traits that you might normally use to separate out genera and species.”

Seeking traits to separate specimens is “Pulling a Larry Martin“. Don’t do that. It leads to madness due to convergence, or, in this case, backing away from what must be done: a comprehensive phylogenetic analysis with all the anurognathid taxa and parts thereof laid out, lumped and separated.

“That said, there are some bits of variation which while commented on before are quite notable in this context (and there is more coming on this in a future paper that I’m involved in). The length of the tail is really variable and while these are as a whole short-tailed (even the longest of them is much shorter than other non-pterodactyloids) there is really quite some difference between the longest and the shortest. I don’t know what this means but it’s an area worthy of greater attention.

Unfortunately, Hone only crudely illustrates the variety found in anurognathid humerus shapes, but omits doing the same for the tails, or any other body parts, especially the skulls. If an amateur can do it (Figs. 1–4), a paid professional and a PhD should be able to do it that much better.

“Similarly, the smaller anurognathids tend to have extraordinarily large heads and the larger ones rather small ones.

This needed to be illustrated and documented. Reconstructions (see Fig. 4) do not reflect and confirm Hone’s observation.

“There could be ontogentic effects here since many of the smaller specimens are juveniles but it stands in contrast with the more general isometry of other pterosaurs, and could be linked to prey sizes or even eye size. If they are, any [sic] many people suspect, nocturnal then juveniles need huge heads to house huge eyes.”

Hone is correct with regard to pterosaur isometry, so why then does he label some pterosaurs ‘juveniles’, rather than small adults of distinct genera? The huge eyes guess is easily resolved by tracing each specimen and locating the eyes, none of which are ‘huge”, with the exceptions of Batrachognathus (Fig. 5) having the most owl-like eyes and most binocular. Even so, those eyes remain in the back half of the skull, as in ALL other pterosaurs.

Figure 5. Dorsal and lateral views of three anurognathid pterosaurs. From left to right, Dendrorhynchoides, Batrachognathus and Jeholopterus, all crushed dorsoventrally, due to the skull’s greater width.

Hone continues
“Finally, there is the issue of the ‘folded’ wings. While some disarticulation can occur in decaying pterosaurs unless the specimen has disintegrated the various bones of the wing finger stay together. Presumably they are held together by numerous strong ligaments or they would not be able to hold up the forces of flight. It’s a very derived condition since of course all other archosaurs (indeed tetrapods generally) can flex their fingers.

Pterosaurs are not archosaurs. This is yet another myth Hone promotes without citing competing studies. He tried to do so once, but choked on the attempt, kowtowing to the agenda of his professor and mentor, Mike Benton. Hone has not been under the influence of Benton for over a decade, so he should show a little independence now. As a PhD pterosaur expert, knowing what a pterosaur is… that is his job and he is not doing his job. More on the wing issue below.

Anurognathids however, despite having some exquisitely preserved specimens, and nearly all of them being basically articulated, show the joints of the wing finger being flexed. This suggests that they are doing something really rather different with their wings, when flying or even when on the ground.

Not at all. The small size of most anurognathids means the wing finger did not need to be as robust as in the larger clades. That alone could account for the flexion seen in many anurognathid wing phalanges (Figs. 4, 6). There’s also taphonomy. And speaking of wings, no pterosaur fossil shows the wing membrane extending down the thigh to the ankle, as shown in the Witton illustrations (Figs. 1, 2).

Figure 6. Click to enlarge. Tracing of Jeholopterus using DGS. Dorsal view of Jeholopterus based on the tracing. Lower left images include an unidentified pair of semi-circles too large to be embryo upper temporal fenestrae (that was the first guess). The tail is not particularly short when stretched to its full length, despite the reduced length of the individual caudals. The red ellipse represents a hypothetical egg shape. The abdomen was not so wide. The ribs would have had a ventral component and direction, which they do not have here. Note the right angle femoral head, ideal for parasagittal locomotion, like a dinosaur.

“One thing to note is that this is also seen in one other set of pterosaur specimens – embryos. That implies that either anurognathids have inherited this trait from their ancestors (if they are, as some suggest, the first branching group of pterosaurs) or have secondarily acquired what is essentially a paedomorphic trait of wing flexion.”

If Hone had produced a valid cladogram, like the LPT, he would have been able to find a solution to his own problem. See figure 4 for a quick graphic review.

“I’ll leave it there for now. There’s plenty more in the paper that you can read and there is obviously more research to come (indeed I’m working on another anurognathid paper that’s come about in part through this work) so don’t want to go over this in detail when it’s already a review. Hopefully this does sort out a few issues and pave the way for a better understanding of these most interesting of pterosaurs.”

In counterpoint, and allowing for a little verbal showmanship on Hone’s part (e.g. using “revising” instead of “reviewing” in his PR ), all pterosaurs should be equally interesting because taxon omission by PhDs is a traditional sin. Granted, Hone is infatuated with anurognathids, like the proud father of any new paper generally should be. Unfortunately, because this paper is already in print, it is now too late to give it the care and attention it should have had when still in his mind and on his monitor.

David Hone is still a young man.
I hope that someday he will see the light, crawl out of Benton’s shadow, do the work he is paid to do, stop hiding behind taxon and citation omission, and ultimately become the pterosaur expert he trained to be.

References
Hone DWE 2020. A review of the taxonomy and palaeoecology of the Anurognathide (Reptilia, Pterosauria). Acta Geologica Sinica. online link

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Papers and abstracts omitted by Hone 2020
Peters D 1995. Wing shape in pterosaurs. Nature 374, 315-316.
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 2002. A New Model for the Evolution of the Pterosaur Wing – with a twist. – Historical Biology 15: 277–301.
Peters D 2003. The Chinese vampire and other overlooked pterosaur ptreasures. ournal of Vertebrate Paleontology, 23(3):87.
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.
Peters D 2010. In defence of parallel interphalangeal lines.
Historical Biology iFirst article, 2010, 1–6 DOI: 10.1080/08912961003663500
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

See a pattern here?
Kids, if you want to get cited, get your PhD and go with the traditional bias and flow. Be willing to ignore competing citations if they come from outsiders who are willing to do the work and go the extra mile without getting paid [heavy on the sarcasm here, for those who are thinking about quote-mining this paragraph].

Lepidosaurian epipterygoids in basal pterosaurs

In 1998 lepidosaurian epipterygoids
were found in the basal lepidosaur tritosaur, Huehuecuetzpalli (Fig. 1, Reynoso 1998; slender magenta bones inside the cheek area).

Figure 1. Huehuecuetzpalli has a tall, narrow epipterygoid, as in other lepidosaurs, and just a pore of an antorbital fenestra in the maxilla.

About two years ago
previously overlooked lepidosaurian epipterygoids were identified here in a more derived lepiodaur tritosaur, Macrocnmeus (Fig. 2, slender green bones in the orbit area) for the first time.

Figure 2. Macrocnemus fuyuanensis (GMPKU-P-3001) in situ and as traced by the original authors, (middle) flipped with colors applied to bones, and (above) bone colors moved about to form a reconstruction. Darker yellow and darker green are medial views of premaxilla and maxilla. Note the long ascending process of the premaxilla and the palatal elements seen through the various openings all overlooked by those with firsthand access to the fossil. Epipterygoids are lepidosaur synapomorphies not present in protorosaurs.

Until now,
no one has ever positively identified lepidosaurian (slender strut-like) epipterygoids in a pterosaur. In the large reptile tree (LRT, 1737+ taxa) and the large pterosaur tree (LPT, 251 taxa) Bergamodactylus (MPUM 6009) nests as the basalmost pterosaur. Here is the skull in situ with DGS colors applied, as traced by Wild 1978 (above), and reconstructed in lateral and palatal views (below) based on the DGS tracings.

Figure 3. Bergamodactylus skull in situ and reconstructed. Wild 1978 tracing above. Note the break-up of the jugal. Note the fusion of the ectopterygoids with the palatines producing ectopalaatines.

The lepidosaurian epipterygoids of Bergamodactylus
(slender bright green struts in the cheek/orbit area in figure 3), or any pterosaur over the last 200 years, are identified here for the first time, further confirming the lepidosaurian status of pterosaurs (Peters 2007, the LRT). Sorry I missed these little struts earlier. When you don’t think to look for them, you can overlook them.

Figure 4. Eudimorphodon epipterygoids (slender green struts).

Now you may wonder how many other pterosaurs
have overlooked epipterygoids? A quick look at Eudimorphodon reveals epipterygoids (Fig. 4, bright green struts). Other Triassic pterosaurs include:

1. Austriadactylus SMNS 56342: slender strut present
2. Austriadactuylus SC 332466: slender strut present
3. Raeticodactylus : slender strut is present (identified on link as a stapes)
4. Preondactylus: slender strut present
5. Dimorphodon: amber strut over squamosal (Fig. 5 in situ image), 
6. Seazzadactylus MFSN 21545: slender struts present, tentatively identified by Dalla Vecchia 2019, but as more than the slender struts they are) (Fig. 6).

Figure 5. The skull of Dimorphodon macronyx BMNH 41212. Above: in situ. Middle: Restored. Below: Palatal view. The slender yellow strut on top of the red squamosal in situ is a likely epipterygoid.

Figure 6. Seazzadactylus from Dalla Vecchia 2019. Here the epipterygoid struts are more correctly and less tentatively identified.

Hard to tell in anurognathids
where everything is crushed and strut-like. Hard to tell in other pterosaurs because the hyoids look just like epipterygoids. Given more time perhaps more examples will be documented that are obvious and irrefutable.

Added a few days later:

Added Figure. Here’s the Triebold specimen of Pteranodon (NMC41-358) with epipterygoid splinters in bright green.

Here’s the Triebold specimen of Pteranodon
(NMC41-358, added figure) with epipterygoid splinters in bright green. So start looking for the epipterygoid in every pterosaur. We’ll see if it is universal when more pterosaur specimens of all sorts are presented.

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References
Dalla Vecchia FM 2019. Seazzadactylus venieri gen. et sp. nov., a new pterosaur (Diapsida: Pterosauria) from the Upper Triassic (Norian) of northeastern Italy. PeerJ 7:e7363 DOI 10.7717/peerj.7363
Peters D 2007. The origin and radiation of the Pterosauria. In D. Hone ed. Flugsaurier. The Wellnhofer pterosaur meeting, 2007, Munich, Germany. p. 27.
Reynoso V-H 1998. Huehuecuetzpalli mixtecus gen. et sp. nov: a basal squamate (Reptilia) from the Early Cretaceous of Tepexi de Rodríguez, Central México. Philosophical Transactions of the Royal Society, London B 353:477-500.
Wild R 1978. Die Flugsaurier (Reptilia, Pterosauria) aus der Oberen Trias von Cene bei Bergamo, Italien. Bolletino della Societa Paleontologica Italiana 17(2): 176–256.

wiki/Bergamodactylus
wiki/Huehuecuetzpalli
wiki/Homoeosaurus
wiki/Bavarisaurus

Pre-pterosaur skull evolution

Pterosaurs are chiefly known by their post-cranial traits.
Here (Fig. 1) a diagram is presented of pterosaur ancestor skulls in phylogenetic order. Alongside this diagram is a list of general trends documented from the tritosaur lepidosaur, Huehuecuetzpalli (at top), to Macrocnemus to Cosesaurus to Longisquama and culminating with the basal pterosaur, Bergamodactylus (at bottom).

Figure 1. Skulls of pterosaur ancestors from Huehuecuetzpalli through Macrocnemus, Cosesaurus, Longisquama and the pterosaur Bergamodactylus.

Huehuecuetzpalli never fits well
into traditional squamate cladograms because it is not a member of the Squamata.

Earlier we looked at the gradual evolution
of the manus in these taxa (Fig. 2). You won’t find evidence like this ‘out there’ in the academic literature where PhDs continue to say, “We still don’t know the ancestors to pterosaurs.” This is rather embarrassing for them, if not now, then someday.

Figure 2. Click to enlarge. The origin of the pterosaur wing and whatever became of manual digit 5?

Addendum: originally published online on Facebook yesterday:
For my paleo friends… this is Cosesaurus (Fig. 3), a lepidosaur, not closely related to living lizards, that was able to run bipedally, like some living lizards do by convergence. It had sprawling limbs, but created a narrow gauge trackway matching Early to Middle Triassic Rotodactylus footprints found from Europe to North America. Lateral toe (#5) uniquely bent back to imprint dorsal side down behind the other four regular toes.

Figure 3. Click to enlarge and animate. Cosesaurus flapping – fast. There should be a difference in the two speeds. If not, apologies. Also, there should be some bounce in the tail and neck, but that would involve more effort and physics.

The curved, stem-like, immobile coracoid is an indicator of flapping (birds share this trait), matched to a strap-like scapula (birds share this trait). The interclavicle overlaps the sternum and clavicles to create a pre-sternal complex, as in pterosaurs. A tiny pterosaur-like prepubis is present. So is an anterior projection of the ilium (top pelvic bone) typically found only in bipeds. Two wrist bones migrated to the thumb side of the wrist to create a pteroid and preaxial carpal, otherwise only found in pterosaurs (but similar, by convergence, to the panda’s ‘thumb’). The tail is extremely narrow and stiff.

Extradermal membranes extend from the crest of the skull to the back of the pelvis. Fibers (pre-wings) trail the forelimbs. A membrane trails each hind limb. These and many other traits are shared with pterosaurs, the flying reptiles of the Mesozoic.

Like birds, pterosaur ancestors used their decorative traits (feathers, membranes) for display, including flapping prior to being able to fly. Running bipedally enabled breathing while running (something quadrupedal undulating lizards cannot do). Bipedal locomotion increased stamina and warmed up the metabolism. So secondary sexual traits (decorations and behavior for display) helped create both birds and pterosaurs.

I studied the one-of-a-kind fossil, a hand-sized mold of such exquisite detail that it also preserved a small jellyfish, in Barcelona in the 1990s where it was inappropriately wrapped in a few layers of toilet paper. In 2000 I described Cosesaurus as an ancestor to pterosaurs, and did so by adding it to four previously published phylogenetic analyses.

Unfortunately, that peer-reviewed and academically published paper has been ignored ever since, for reasons I still cannot fathom other than I have no science degree, let alone a PhD. To this day paleontologists repeat the phrase, “We still don’t know where pterosaurs come from.” Frustrating, but I’ve gotten used to it. I guess this posting is just a chance to vent.

For more exquisite Cosesaurus details, click here: http://reptileevolution.com/cosesaurus.htm

Testing pterosaur ingroup and outgroup relationships: Baron 2020

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)”.

Outgroups in Baron 2020 include massive and non-volant Postosuchus + Herrerasaurus and smaller non-volant Marasuchus and Lagerpeton.

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.

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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.

http://reptileevolution.com/reptile-tree.htm
http://reptileevolution.com/MPUM6009-3.htm

If you ever get ‘beaten up’ by a gang of paleontologists…

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).

Author Jon Ronson
on the Joe Rogan Experience #668, discusses his book, ‘So you’ve been publicly shamed.’ Here he takes the antagonists’ point-of-view:

“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.

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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.

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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.

wiki/Oculudentavis

Advice for would be paleontologists: stay professional!

A Blind Eye Toward Pterosaur Origins

Rachel Carson and Marie Tharp

John Ostrom: The man who saved dinosaurs

Let’s open up an old can of worms

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.

Some hits later ‘discovered’ by others:
https://pterosaurheresies.wordpress.com/?s=heard+it+here+first&submit=Search

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”

 

 

 

 

 

 

 

 

From Berkeley: pterosaur origins and whale evograms

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 after Langobardisaurus, 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.

https://pterosaurheresies.wordpress.com/2011/09/09/the-origin-of-the-pterosaur-sternal-complex/

https://www.researchgate.net/publication/328388746_The_triple_origin_of_whales

https://evolution.berkeley.edu/evolibrary/article/evograms_02

https://evolution.berkeley.edu/evolibrary/article/evograms_03

https://evolution.berkeley.edu/evolibrary/article/evograms_04

https://evolution.berkeley.edu/evolibrary/article/evograms_05

https://evolution.berkeley.edu/evolibrary/article/evograms_06

https://evolution.berkeley.edu/evolibrary/article/evograms_07

https://ucmp.berkeley.edu/vertebrates/flight/pter.html

https://en.wikipedia.org/wiki/Kevin_Padian

Oculudentavis reply: bird? lizard? or option #3?

O’Connor et al. 2020 are not giving up without a fight. 
Now they are arguing against a published objection (Li et al. 2020) to their interpretation of Oculudentavis as a strange tiny bird encased in Early Cretaceous Burmese amber. Citation and excerpts are below. You have to admire their courtesy while defending their hypothesis with every weapon they have… except the correct one.

From the O’Connor et al. abstract:
“We welcome any new interpretation or alternative hypothesis regarding the taxonomic affinity of the enigmatic Oculudentavis khaungraae. However, here we demonstrate that Li et al. have failed to provide conclusive evidence for the reidentification of HPG-15-3 as a squamate. We analyse this specimen in a matrix that includes a broad sample of diapsid reptiles and resolve support for this identification only when no avian taxa are included. Regardless of whether this peculiar skull belongs to a tiny bird or to a bizarre new group of lizards, the holotype of Oculudentavis khaungraae is a very interesting and unusual specimen, the discovery of which represents an important contribution to palaeontology.”

‘Regardless’ indeed, as a scientist it’s your job to figure this out. This time it’s not either this or that… it’s something else, a third alternative nobody wants to talk about.

FIgure 1. CT scan model from Li et al. 2020, who denied the presence of a quadratojugal and an antorbital fenestra, both of which are present. Arrow points to antorbital fenestra Colors applied here. In the LRT Oculudentavis nests with Cosesaurus, a pterosaur precursor. See figure 2.

Interesting that O’Connor et al. bring up taxon exclusion,
yet keep excluding the taxa that would resolve this stand-off, members of the Fenestrasauria (Peters 2000). The O’Connor et al. taxon list was ‘broad’, but not broad enough.

Figure 2. Cosesaurus flapping animation. This sister to Oculudentavis in the LRT was a flapping lizard and a pterosaur precursor provided with locked down coracoids, a aternum, strap-like scapulae, an antorbital fenestra a large orbit and bulbous cranium.

From the O’Connor et al 2020 introduction.
“We welcome any new interpretation or alternative hypothesis regarding the taxonomic affinity of the enigmatic Oculudentavis khaungraae.”

No they don’t! They were sent an alternative hypothesis the day after publication. (Not whining. Just stating fact in the face of all their righteous signaling).

“Several of the squamate morphologies described by Li et al. were noted by ourselves in the original manuscript (e.g., pleurodont dentition, morphology of the eye)1. However, we will argue that other features which Li et al. describe as unusual for archosaurs are not incompatible with our original interpretation.”

The solution continues to be the third choice, which both sides continue to overlook (= taxon exclusion).

From the O’Connor et al. text,
“Li et al. criticize our phylogenetic analysis yet provide none themselves.”

Good point! A phylogenetic solution is paramount. Otherwise you’re “Pulling a Larry Martin” trying to make your argument with possibly convergent traits, not last common ancestry, which, when done right, is irrefutable.

The O’Connor et al. text continues,
“However, this does highlight a weakness of a majority of phylogenetic analyses utilized to describe new taxa. If a new specimen is identified as a bird it is analysed in a matrix targeted at birds; if the specimen is identified as a lizard, it is analysed in a matrix targeted at lizards. Descriptions of new taxa rarely include phylogenetic datasets targeted at higher level relationships such as all of Reptilia or Amniota that would be capable of testing alternative placements.”

Another excellent point! That’s why the large reptile tree (LRT, 1697+ taxa) is online and available for anyone to use, precisely for problem taxa, like Oculudentavis.

O’Connor et al. report,
“However, removal of all avian taxa results in Oculudentavis being resolved among squamates.”

That’s interesting! (and supports Peters 2007). By the way, such a phylogenetic leap rarely happens in the LRT. Removing large proximal clades usually results in the next closest clade nesting the enigma taxon.

O’Connor et al. conclude:
“Oculudentavis may represent an outstanding case of convergent evolution between squamates and birds, the likes of which biologists have rarely seen before.”

Well, yes, if you’re referring to flapping, flying lizards (aka ‘pterosaurs’; Peters 2007). This citation is rare due to academic suppression.

Unfortunately, O’Connor et al. are still missing the headline of this story: Oculudentavis is a late-surviving member of the Middle Triassic radiation that produced pterosaurs. The arose from an overlooked third clade of Lepidosaurs, some on which became protorosaur mimics. Others became archosaur mimics.

“However, regardless of whether this peculiar skull belongs to a tiny bird or to a bizarre new group of lizards, the holotype of Oculudentavis khaungraae is a very interesting and unusual specimen, the discovery of which represents an important contribution to palaeontology.”

It won’t be ‘bizarre’ once you understand what Oculudentavis is: a sister to the lepidosaur tritosaur fenestrasaur Cosesaurus. Just expand that taxon list and come to an agreement.

Again, when someone uses the word “bizarre” they have not included all the pertinent taxa. It’s sign they are giving up. Nothing is bizarre in the LRT. All enigmas are nested. No taxon stands alone.

This is what citation avoidance and suppression results in. Neither party understands what they have here. We looked at this exact problem yesterday.

We looked at the Oculudentavis controversy
earlier here, here, here, here and here. And the story has yet to reach a conclusion.

Figure 3. The origin of pterosaurs now includes Kyrgyzsaurus, nesting between Cosesaurus and Sharovipteryx.

Postscript:
The post-crania of Oculudentavis remains unknown. It could resemble anything from Cosesaurus (Fig. 3) through pterosaurs, given its Early Cretaceous age and the variety we already find in the clade Fenestrasauria, from which it arose.

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References
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 (Not cited in O’Connor et al. 2020)
O’Connor J Xing, Chiappe L, Schmitz L, McKellar R,  Li G and Yi Q 2020. Reply to Li et al. “Is Oculudentavis a bird or even archosaur?” bioRxiv 2020.06.12.147041 (preprint)
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 2007. The origin and radiation of the Pterosauria. In D. Hone ed. Flugsaurier. The Wellnhofer pterosaur meeting, 2007, Munich, Germany. p. 27.
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.

https://pterosaurheresies.wordpress.com/2020/03/22/oculudentavis-in-more-incredible-detail-thanks-to-li-et-al-2020/

You heard it here first: Others also doubt the theropod affinities of Oculudentavis

The now famous tiny skull in amber, Oculudentavis, 
(Fig. 1; Xing et al. 2020) continues as a topic of conversation following its online publication in Nature and two previous PH posts here and here.

Figure 1. Oculudentavis in amber much enlarged.

Several workers have also thrown cold water
on the tiny theropod affinities of Oculudentavis. Oddly, all seem to avoid testing or considering in their arguments the sister taxon in the large reptile tree (LRT): Cosesaurus (Fig. 2). Instead, they report on what Oculudentavis is not. Examples follow:

Dr. Andrea Cau writes in TheropodaBlogspot.com Link here (translated from Italian using Google translate): 

“I believe that the interpretation proposed by Xing et al. (2020) is very problematic. Oculudentavis in fact has numerous anomalous characteristics for a bird and even for a dinosaur. And this makes me doubt that it is classifiable within Dinosauria (and Avialae).

1. Absence of anti-orbital window. [not true, click here]
2. Quadrate with large lateral concavity. This character is not typical of dinosaurs, but of lepidosaurs. [that quadrate is twisted, the other is not, the concavity is posterior in vivo]
3. The maxillary and posterior teeth of the maxilla extend widely below the orbit.
4. Dentition with pleurodont or acrodont implant.
5. Very large post-temporal fenestra.
6. Spoon-shaped sclerotic plates is typical of many scaled lepidosaurs.
7. Coronoid process that describes a posterodorsal concavity of the jaw reminds more of a lepidosaur than a maniraptor.
8. Very small size comparable to those of the skulls of many small squamata found in Burmese amber.

“In conclusion, there are too many “lizard” characters in Oculudentavis not to raise the suspicion that this fossil is not a bird at all, let alone a dinosaur, but another type of diapsid, perhaps a scaled lepidosaur, if not possibly a specimen very immature than some other Mesozoic group (for example, a Choristodere). It is well known that many types of reptiles present in the final stage of embryonic development and in the very first moments after hatching a cranial morphology similar to the general one of birds (of in fact, the bird skull is a form of “infantilization” of the classic reptilian skull, extended to the adult).
Unfortunately, the authors, while noting some of the similarities with the squamata, do not test the affinities of Oculudentavis outside Avialae.

“PS: out of curiosity, I tested Oculudentavis in the large Squamata matrix by Gauthier et al. (2012): it turns out to be a stem-Gekkota.”

Note to readers: Neither Gauthier et al. 2012 nor Dr. Cau tested fenestrasaurs, like Cosesaurus… yet another case of taxon exclusion. With regard to phylogenetic age, fenestrasaur tritosaur lepidosaurs, like Oculudentavis, hatch with the proportions of adults (ontogenetic isometry), so the ontogenetic status of this taxon needs further context (e.g. coeval larger adults or smaller hatchlings)/

Update March 14, 2020:
Readwer TG (below) informs me that Cau’s study did include Cosesaurus. My reply follows: “Thank you, Tyler. Good to know. My mistake. Strange that his Oculudentavis has traits more like the distinctively different Sphenodon and Huehuecuetzpalli, when it looks more like Cosesaurus in every regard. Here’s a guess based on experience: neither he nor Gauthier went to Barcelona to see Cosesaurus, and neither did either reference or cite Peters 2000 or the ResearchGate.net update. And Cau probably used the Xing et al. 2020 ink tracing of Oculudentavis rather than the more detailed DGS tracing I produced (or he could have traced himself), since he did not see the tiny antorbital fenestra [or the twisted quadrate]. Just a guess based on 20 years of experience.” 

PS. Neither Gauthier nor Cau showed their work (e.g. skulls diagrammed with suture interpretations as shown at ReptileEvolution.com links). Therefore we cannot know if or where mistakes were made in their scoring attempts. In a similar fashion, testing revealed a raft of scoring problems with Nesbitt 2011, covered earlier here in the last of a nine-part series. 

Dr. Darren Naish updates his original post in Tetrapod Zoology  
with the following notes:

“A number of experts whose opinions I respect have expressed doubts about the claimed theropod status of the fossil discussed below and have argued that it is more likely a non-dinosaurian reptile, perhaps a drepanosaur or lepidosaur (and maybe even a lizard). I did, of course, consider this sort of thing while writing the article but dismissed my doubts because I assumed that – as a Nature paper – the specimen’s identity was thoroughly checked and re-checked by relevant experts before and during the review process, and that any such doubts had been allayed. At the time of writing, this proposed non-dinosaurian status looks likely and a team of Chinese authors, led by Wang Wei, have just released an article [not linked] arguing for non-dinosaurian status. I don’t know what’s going to happen next, but let’s see. The original, unmodified article follows below the line…”

We can only trust what Dr. Naish reports regarding his private doubts as to the affinities of Oculudentavis. Here he confesses to assuming the ‘opinions’ of ‘relevant experts’ got it right, like all the other journalists who reported on this discovery, rather than testing the hypothesis of Xing et al. 2020, like a good scientist should.

While we’re on the subject of confessing, 
earlier the LRT nested Oculudentavis with Cosesaurus (Fig. 1) despite the former’s much later appearance and derived traits, like the essentially solid palate. I failed to mention the skull of Oculudentavis shares just a few traits with another Late Triassic fenestrasaur, Sharovipteryx (Fig. 1). If Oculudentavis also had a slender neck, like the one in Sharovipteryx, perhaps that was one reason why only the skull was trapped in pine sap, later transformed into amber. Just a guess.

Figure 2. Cosesaurus was experimenting with a bipedal configuration according to matching Rotodactylus tracks and a coracoid shape similar to those of flapping tetrapods. Long-legged Sharovipteryx was fully committed to a bipedal configuration.

Note:
with locked down and elongate coracoids, all members of the clade Fenestrasauria were flapping like flightless pterosaurs. Appearing tens of millions of years after the Middle Triassic genesis of fenestrasaurs, who knows what sort of post-crania tiny Early Cretaceous Oculudentavis may have evolved! Known clade members already vary like Hieronymus Bosch fantasy creatures.

The LRT is a powerful tool for nesting taxa
while minimizing taxon exclusion. And it works fast. Feel free to use it in your own studies.

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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 2007.The origin and radiation of the Pterosauria. In D. Hone ed. Flugsaurier. The Wellnhofer pterosaur meeting, 2007, Munich, Germany. p. 27.
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.

late arrival:

Wang Wei, Zhiheng Li, Hu Yan, Wang Min, Hongyu Yi & Lu Jing 2020. The “smallest dinosaur in history” in amber may be the biggest mistake in history. Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) of the Chinese Academy of Sciences: Popular Science News (2020/03/13)
http://ivpp.cas.cn/kxcb/kpdt/202003/t20200313_5514594.html

from B. Creisler’s translated post at dml.cmnh.org:

“Here is the list of problems found by the authors:

Doubts 1. Can the shape of the head prove that it is a bird? 
Doubt 2. Unreasonable Phylogenetic Analysis 
Doubt 3. Birds without antorbital fenestrae? 
Doubt 4. “Birds” with pleurodont teeth? 
Doubt 5. Mysterious quadratojugal bone 
Doubt 6. Scleral bones only found in lizards 
Doubt 7. The bird with the most teeth in history? 
Doubt 8. Body size 
Doubt 9. No feathers? 
Doubt 10. Strange wording and logic chains

We hope that the authors of the paper will respond publicly to these questions as soon as possible. At the same time, it is hoped that the authors of the paper will quickly release the raw data of CT scans, so that other scientists can verify the existing results based on the raw data.”

July Post-Script
Authors retract the paper, according to Nature.