Partitioning the Large Reptile Tree – part 1 – cranial characters only

Short and sweet today.

Bennett (2012) discussed the value of partitioning a family tree into discrete parts (skull, limbs, post-crania, etc.) to help understand the tree as a whole. Here I deleted all the post-cranial traits from the large reptile tree. I also deleted any taxa for which the skull was unknown (otherwise there would be no scores at all for such taxa).

The results (Fig. 1) closely mirror the original large reptile tree.

he large reptile tree, all post-cranial traits deleted.

Figure 1. The large reptile tree, all post-cranial traits deleted. A few taxa without skulls are also deleted. This is one demonstration of partitioning. Tomorrow comes another. Green areas mark loss of resolution. Gray = Reptilia. Orange = new Lepidosauromorpha. Yellow = new Archosauromorpha.

As always, I encourage readers to see specimens, make observations and come to your own conclusions. Test. Test. And test again.

Evidence and support in the form of nexus, pdf and jpeg files will be sent to all who request additional data.

References
Bennett SC 2012. The phylogenetic position of the Pterosauria within the Archosauromorpha re-examined. Historical Biology. iFirst article, 2012, 1–19.

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Where is that Long Sought Youngina Phylogenetic Analysis?

Youngina and Youngoides are key fossil taxa in the ancestry of the Archosauriformes according to the large reptile tree. Derived from Prolacerta and the real Prolacertiformes (not including Tanystropheus, Macrocnemus, etc.), this clade of small unspecialized reptiles is known from several specimens, some found grouped together en masse.

The large reptile tree recovered Youngina basal to Prolacerta and Proterosuchus.

Figure 1. The large reptile tree recovered Youngina basal to Prolacerta and Proterosuchus. Other Youngina nested between Prolacerta and Proterosuchus. Still others nested closer to Choristoderes.

Gow 1974
To my knowledge, not since Gow 1975 has there been a comprehensive look at the Youngina clade, and that one could have been more detailed. If so, that means we haven’t seen a phylogenetic analysis of this clade and their place in the reptile panoply. The Youngina clade includes a variety of morphologies, which some have attributed to crushing. This is worth testing because the differences may have some phylogenetic value.

Let’s get this one published and see what is recovered. Don’t forget to add Orovenator and the choristoderes, which were also derived from the Youngina clade.

As always, I encourage readers to see specimens, make observations and come to your own conclusions. Test. Test. And test again.

Evidence and support in the form of nexus, pdf and jpeg files will be sent to all who request additional data.

References
Broom R 1914. A new thecodont reptile. Proceedings of the Zoological Society of London, 1914:1072-1077.
Gardner NM, Holliday CM and O’Keefe FR 2010. The braincase of Youngina capensis(Reptilia, Diapsida): New insights from high-resolution CT scanning of the holotype. Paleonotologica Electronica 13(3):online PDF
Gow CE 1975. The morphology and relationships of Youngina capensis Broom and Prolacerta broomi Parrington. Palaeontologia Africana, 18:89-131.
Olsen EC 1936. Notes on the skull of Youngina capensis Broom. Journal of Geology, 44 (4): 523-533.
Reisz RR, Modesto SP and Scot DMT 2011. A new Early Permian reptile and its significance in early diapsid evolution. Proceedings of the Royal Society, London B
doi:10.1098/rspb.2011.0439

On my way to becoming “the bane” of paleontologists…

reptileevolutiion.com must be stopped

…and prior to my ‘descent’ from a promising career as an author/illustrator…
I remember well the moment I ventured into paleontology…
(queue the dream sequence music and wavy screen).

I was standing in the shower thinking about a book of giant animals, all to the same scale, some on gatefold pages. That had never been done before. That idea, several years later, turned into the book Giants. Following that, a bunch of other books, along with museum visits and talks at SVP conventions, digs, trips around the world, websites, blogs, etc. etc.

Now I wonder,
if I had not had that single creative thought in the shower… Where would I be?

More to the point, though…
Would other paleontologists have filled the empty niches [I never would have filled] in that alternate universe?

… Would someone else have looked upon Cosesaurus, Huehuecuetzpalli and other non-archosaurs and recognized them as pterosaur, drepanosaur and tansytropheid ancestors?

… Would someone else have started tracing tetrapod photographs to collect as much data as possible to…

… Assemble a very large reptile tree (now up to 315 taxa) supplemented by a very large pterosaur tree (with tiny pterosaurs included)? This led to several shifts in traditional nestings.

Birdman of Alcatraz

Completely in isolation Robert Stroud, the Birdman of Alcatraz, played here by Burt Lancaster, experimented with birds, created new medicines for them and wrote several books.

And yes, I made mistakes along the way. Most, like my mistakes interpreting Cosesaurus, were corrected in ReptileEvolution.com because they were rejected from publication. I had hoped that my website might be seen as redemption from mistakes that have dogged me. But no, Darren Naish and others continue to mine my wastebasket and while virtually ignoring any good that comes out of ReptileEvolution.com. So no redemption is possible in the present universe.

Ironically
When the Tetrapod Zoology article came out the interest in ReptileEvolution popped up 50% for the month of July, from fewer than 100,000 hits a month to 146,000. By the end of October, ReptileEvolution will have its one-millionth hit for the year starting January 1. July also saw a 50% rise in unique visitors.

I have the feeling
(actually more than a feeling – see below), after reading Bennett (2012) that he and everyone else on the archosaur side of the fence (like Nesbitt and Bursatte) are trying to tip-toe around my papers. They don’t want to notice the only peer-reviewed hypothesis that seems to make sense with regard to pterosaur ancestry. It’s still the only hypothesis in which pterosaurs don’t “appear suddenly in the fossil record.” Somehow, perhaps by virtue of my non-PhD standing, I may have created “a stink” around these taxa so that others avoid them. Is this even possible? Can paleontologists really act so childish??

A few years ago
Bennett told me in quiet conversation that if any more papers of mine get published they will be ignored by the pterosaur community a priori. So, even though “the truth is out there,” now the pterosaur community has decided to stick to their guns and not recognize or even argue against the possibility of fenestrasaurs as pterosaur ancestors. Moreover, in order to completely avoid any issue that I am in favor of, they have decided to support issues  and whacked-out hypotheses that cannot possibly be supported (just thumb through a few dozen past posts to get a flavor for these).

No Good For Nothin’
Perhaps that’s why the broad brush approach has been taken against ReptileEvolution.com, (“why the world has to ignore…”) rather than taking the surgical scalpel against specific errors or omissions therein. You know I love hearing about specific problems, because then I have the chance to correct them.  Unfortunately, when people like Mark Witton do pick out problems, sadly, their arguments are never direct and are rarely valid. Darren Naish stooped so low as to use the work of other artists to ridicule morphologies that aren’t even on my site! Talk about propaganda!!

Bennett is not the only one
I’ve mentioned this before: Hone and Benton’s two part (2007, 2009) papers on pterosaur supertrees referenced my 2000 paper in 2007. Then, in 2009 their second paper acted as if I did not exist.  Rather, they gave false credit for the “prolacertiform” hypothesis to Bennett (1996).

Jackie Robinson

Jackie Robinson, the first black major league ball player in 1947. He faced abuse daily.

It’s so strange. Makes a person feel like Jackie Robinson in 1947 (see the upcoming movie trailer here if you are unfamiliar with this American ballplayer).

Since 2003 I’ve been shunned, black-balled, ignored, ridiculed, rejected and reviled. Others have been given credit for my ideas. Still, I’m here because there are problems in paleontology that need solutions. If the ‘diphyletic reptile tree’ and ‘pterosaurs are lizards’ hypotheses are so wrong, surely better candidates can be presented.

So where are they?

Paleontologists attack and ridicule my methods and my lack of contact with certain actual specimens. What they never seem to attack, study, embrace and ponder are the specimens themselves and their place in the tree. And they rarely expose their analyses to other than the traditional inclusion sets. They must be afraid to do so because it is relatively easy to do so.

It’s been 12 years since 2000
and I can’t believe that no one has ventured a good look at the fenestrasaurs and published on their findings. Sure there’s Senter 2003, but his tracings are cartoons and the traits are riddled with errors. I’ve read that Robert Reisz looked at Sharovipteryx several years ago and even excavated parts of it. So where is that paper? There are also rumors about fresh studies on Longisquama. Nothing, so far, on Cosesaurus, unfortunately.

Just like the Early Triassic: a wide open playing field
The lack of professional work on the subjects I cover leaves wide open all sorts of discoveries for the heretics and the amateurs among us.

This is a plea for anyone with a PhD to create a large reptile tree and test the results of smaller earlier studies.  Why are workers shying away from this? If it’s a lot of work give the assignment to a promising grad student. Then we’ll find validity. Don’t ridicule the hypothesis until you’ve tested it or have seen someone else’s test of it.

If you find errors here or at ReptileEvolution.com, please bring them to my attention so they can be rectified.

As always, I encourage readers to see specimens, make observations and come to your own conclusions. Test. Test. And test again.

Evidence and support in the form of nexus, pdf and jpeg files will be sent to all who request additional data.

Tetrapod Eggshell Trends

Amniotes (= reptiles) produce different sorts of eggs (soft, flexible, rigid). Some are laid shortly after fertilization (most lizards, turtles, birds and crocs). Others are retained within the mother until just before hatching. Still others “hatch” within the mother and give way to live birth (mammals, several distinct clades of lizards, enaliosaurs, choristoderes).

Most fossil taxa are not also known from their eggs. However phylogenetic bracketing (Fig. 1) permits us a good guess as to what sorts of eggs they produced if we know what sort of eggs some clade members produced.

Eggshell trends in reptiles.

Figure 1. Click to enlarge. Eggshell trends in reptiles. Here the different types of shells permit phylogenetic bracketing of taxa for which no eggs are known. Apologies, this is not the most recent reptile tree.

Eggshells
From the Introduction to eggshells (Berkeley): “Most lizards, snakes, and tuataras lay soft eggs composed of an organic framework and poorly organized calcite crystals. These eggs collapse and shrivel after the animal hatches, and are therefore unlikely to be identified or even preserved in the fossil record.

“Many amniotes, including some lizards, snakes, and turtles, lay eggs with flexible shells. These shells differ from soft shells because of their higher mineral content. Nevertheless, preservation of flexible eggs is also rare in the fossil record.

“Some turtles and geckos, and all crocodilians, dinosaurs, and birds lay eggs with rigid eggshell. The calcite crystals form a relatively thick eggshell of interlocking shell units. Fossilization is more likely to occur in rigid eggshell because the crystalline calcium carbonate (calcite or aragonite) layer is stronger, more durable, and does not shrivel upon hatching.”

In summary, turtles lay all three kinds of eggs. Mammals, lizards and snakes lay eggs with flexible shells or produce live young. Only the more derived reptiles (crocs and dinosaurs including birds) produce hard-shelled eggs. Extinct marine reptiles of all sorts (probably except prehistoric turtles) produced live young.

Reptilian eggs can be separated into three separate groups based on the structure of their shell structure:
1. flexible shells with no calcareous layer
2. flexible shells with a thick calcareous layer, and
3. rigid shells with a well-developed calcareous layer.

Squamates mainly lay eggs with flexible shells. All squamate eggs are flexible except for two subfamilies of gekkos. Some flexible shells contain no calcareous layer, only a shell membrane. This fibrous membrane is comprised of an irregular series of ridges and a finely woven mat of fibers on the outer surface.

Some turtles also have flexible eggs
with a calcareous layer as thick as the shell membrane. Sea turtle eggs have a poorly ordered, open matrix calcareous layer with undefined shell components and pores. In contrast, in emydids and chelydrids (turtle clades) the calcareous layer is highly structured with well-defined components and pores.

Rigid-shelled Eggs
produced by crocodilians, some turtles, dibamids and gekkonids have a well-developed calcareous layer that makes up most of the eggshell and a thin shell membrane. The shell units fit together tightly and interlock.

Monotreme (Mammal) Eggshells 
are soft, leathery and flexible, lacking mineralization and without a calcareous covering. Monotremes (and all mammals) are descendants of extremely tiny early mammals. Their tiny adult size affected the tiny size and composition of the eggs of subsequent mammals.

Unfortunately we know of no pelycosaur or therapsid eggs yet. We have no basal reptile eggs from the Lepidosauromoph branch either. Our best guess is they were leathery.

Enaliosaurs
The marine reptiles (ichthyosaurs, plesiosaurs, nothosaurs, thalattosaurs, placodonts, mesosaurs) were all  live-bearing. There was a recent discovery of Early Permian (280 mya) mesosaur embryos curled into egg shapes within the mother and almost the size of nearby hatchlings. Mesosaurs were either viviparous or they laid eggs ready to hatch in days or minutes, which would have been a precursor to live birth. There is no trace of any eggshell.

EarlyPermianReptileEgg

Figure 2. Size of the earliest known Permian Egg, full scale at 72 dpi. The mesosaur egg was similar in size.

Oldest Reptile Egg
Previous to the mesosaur egg, Romer and Price (1939) described the oldest reptile egg (Admiral Formation Artinskian, 280 mya) based on shape, size, shell-like cracks and chemistry. The internal structure of the nodes and the pattern of their distribution, the type of layering and the microstructure are not like those found in calcareous eggshells.  Hirsch (1979) determined that the reptilian egg was “soft-shelled.”

An Early Archosauriform Egg
Hyphalosaurus, an aquatic choristodere (within the Archosauriformes), had a thin, leathery egg and the embryo was retained within the mother until just prior to hatching. Note that choristoderes are sisters to Proterochampsids and Parasuchians within the Parachosauriformes. Does this mean hard-shelled eggs were restricted to the Archosauria (birds and crocs)? It could.

Pterosaur Eggs
The extreme thinness of pterosaur eggs is at odds with the thick calcareous eggshells of crocs and birds, their putative kin in traditional palaeontology. Their eggs alone tell us that pterosaurs are lizards, as their morphology and phylogeny confirms. The mother carried the egg until just prior to hatching as three full term embryos and one poorly ossified expelled egg from Darwinopterus.

As always, I encourage readers to see specimens, make observations and come to your own conclusions. Test. Test. And test again.

Evidence and support in the form of nexus, pdf and jpeg files will be sent to all who request additional data.

References
Hirsch KF 1979. The oldest vertebrate egg? Journal of Palaeontology 53(5): 1068-1084.
Romer AS and Price Li 1939. The Oldest Vertebrate Egg, Peabody Museum, Yale University, New Haven, Connecticut, American Journal of Science, Volume 237:  826-82.
Hou LH, Li, PP, Ksepka DT, Gao K-Q and Norell MA 2010. Implications of flexible-shelled eggs in a Cretaceous choristoderan reptile. Proceedings of the Royal Society B, 277(1685): 1235-1239. 10.1098/rspb.2009.2035.
Ji Q, Ji S, Lü J, You H and Yuan C 2006. Embryos of Early Cretaceous Choristodera (Reptilia) from the Jehol Biota in western Liaoning, China. Journal of the Paleontological Society of Korea, 22(1): 111-118.
Ji Q, Wu X-C and Cheng Y-N 2010. Cretaceous choristoderan reptiles gave birth to live young. Naturwissenschaften, 97(4): 423-428.  doi:10.1007/s00114-010-0654-2.
Sander PM 2012. Reproduction in Early Amniotes.Science 337, 806.

Bennett 2012 – Still Barking Up the Wrong Pterosaur Tree

I first heard this one at the 2nd Pterosaur Symposium in China.
Bennett (2012) reports that pterosaurs nested between the lumbering and aquatic archosauriforms Proterosuchus and Erythrosuchus. That moves the nesting away from Scleromochlus, Proterochampsids and Parasuchians, the previous archosaur ‘favorite candidates,’ which were earlier derided as “strange bedfellows.”

How is this possible?
Of course this ‘new’ nestinggives us no idea whatsoever as to the gradual accumulation of pterosaurian traits, which is one of the great benefits anywhere and everywhere along the large reptile tree. What do Erythrosuchus and Proterosuchus have to do with pterosaurs???

And everyone thinks that -I- delve into pseudoscience??

Where is the critical thinking here??

Well, to be fair…
I was able to nest pterosaurs with turtles and both nested with sauropterygiformes – but that was to prove a point made only in the absence of half of the Reptilia, the entire new Lepidosauromorpha (where turtles also nested). So anything is possible if you overlook or ignore certain taxa, like Huehuecuetzpalli, Langobardisaurus, Cosesaurus, Sharovipteryx and Longisquama.

Perhaps the title says it all
“The phylogenetic position of the Pterosauria within the Archosauromorpha re-examined.” Bennett (2012) did not even consider other taxa promoted since his 1996 paper. “Did you even consider Sharovipteryx?” I asked him in China, “…the taxon that David Unwin briefly considered?”  He shook his head. Then I shook my head in disbelief. This is truly putting the blinders on. For what possible reason?

Bennett (2012) did include Tanystropheus,
a taxon that was once mistakenly considered a pterosaur (the skeleton was jumbled and the elongated neck bones were mistaken for wing bones). So what happened here? Bennett (2012) did not mention how many extra steps a shift to Tanystropheus would take. Tanystropheus was scored with X or –  for 39 out of 144 traits, despite being completely known.

Partitioning and Congruence
Importantly, Bennett (2012) divided his 1996 dataset into Cranial, Postcranial, Forelimb Hindlimb and Cursorial subsets to see what sort of tree each subset recovered. Loss or resolution plagued most of these subsets. In the large reptile tree there’s not much change when testing cranial  vs post cranial characters, so long as you don’t include any headless specimens with the cranial subset.

Suprageneric Taxa
Bennett (2012) did not test individual genera within Lepidosauromorpha, Rhynchosauria, Proterosuchidae, Erythrosuchidae, Proterochampsidae, Parasuchia, Ornithoduchidae, Suchia or Dinosauria, about half of his included taxa. Earlier we talked about the dangers involved in using such suprageneric taxa, especially when several of Bennett’s taxa are actually Lepidosauromorphs.

Bennett Reports
Bennett (2012) reports: pterosaurs share with basal archosauriforms: 1) presence of palatal teeth (I need to see these before I believe in them), 2) absence of antorbital fossa (Erythrosuchus has one, so does Proterosuchus, but just barely ) and 3) broad puboischiadic plate (medially oriented in Proterosuchus, divided in erythrosuchids). Later Bennett (2012) adds, “absence of cnemial crest.” So true! But this is a plesiomorphic trait.

Against Nesbitt (2011)
Bennett (2012) reflects my own thinking when he writes, “I reject such atomisation of morphology.”

Bennett on Leaping
Bennett (2012) reports, However, in the quadrupedal pterosaurs the increased number of sacral vertebra increased the strength of the connection between the vertebral column and hindlimb so as to better transfer the dynamic forces associated with arboreal leaping primarily powered by the enlarged hindlimb, and associated with flapping of the hindlimb in flight… The long preacetabular process of the ilium in pterosaurs provided enlarged areas of origin and improved angles of pull for hindlimb muscles associated with arboreal leaping and flapping of the hindlimb in flight…” While some of this may be true (doubtful about flapping the hindlimbs), it ignores the long preacetabular process and increased sacrals in Cosesaurus and Sharovipteryx.

Hone Typos
Bennett reported with regard to Hone and Benton (2007, 2008), Hone kindly sent me their Nexus files, and comparing them with the published data sets of Bennett (1996) and Peters (2000) revealed that the inability of Hone and Benton (2007) to replicate the analysis of Bennett (1996) was not the result of differences in the coding of Scleromochlus for Char. 43, but rather was the result of (1) four separate coding errors in retyping the data matrix and (2) leaving eight of the 9s that Bennett (1996) used to code for missing data in the matrix unchanged while using ? as the symbol for missing data and then including 9 in the Symbols statement of the Nexus file so that PAUP treated 9 as a distinct character state rather than as missing data. Similarly, their inability to replicate Peters’ (2000) analysis of a modified Bennett (1996) data set was the result of seven coding errors in retyping Peters’ published data matrix plus two 9s treated as a distinct character state.” This comes as no surprise as many of Hone’s colleagues have expressed similar concerns with Hone’s work in private correspondence.

Ignoring Peters (2010) on Digitigrade Ptero Tracks
Bennett (2012) reports, “…trackway evidence shows them to have been plantigrade quadrupeds (Lockley et al. 1995; Bennett 1997b; Unwin 1997; Mazin et al. 2003) and the complete absence of trackways of basal pterosaurs…” I showed digitigrade tracks in 2010. Why not discuss them? Because Bennett swore he would ignore any papers I published after 2000 and so far he’s doing a pretty good job of keeping his word.

The Centrale
Bennett (2012) reported, “The homologies of the [distal] tarsals are uncertain.” This is only true in the context of an Archosauromorph relationship. Bennett (2012) reported, “but in no case is there any evidence that any of them is the centrale.” Here he ignored or dismissed Peters (2000) as I demonstrated the three distal tarsals are the centrale, dt3 and dt4 when pterosaurs descend from Macrocnemus and Cosesaurus.

The Pteroid
Bennett (2012) reported, “Although the origin and homology of the pteroid is uncertain (Unwin et al. 1996).” This ignores Peters (2009) who showed that Cosesaurus had a pteroid and preaxial carpal.

Bennett’s Tree
Bennett (2012) recovered four trees with its weakest links between Prolacerta and Erythrosuchidae, the nodes which include Tanystropheus, the drepanosaurs and pterosaurs (the by default nested taxa), with the archosauromorph, Proterosuchus, in the middle. Few of these taxa look like their sisters. Many more taxa are needed to demonstrate gradual accumulations of traits.

Acknowledgements
Bennett (2012) “was benefited from conversations and/or correspondence with M.J. Benton, D.W.E. Hone, S. Nesbitt and J.J. Wiens. He thanks S. Brusatte, D.W.E. Hone, S. Nesbitt and P. Senter for kindly providing… Nexus files and pertinent information from their respective analyses. [He] thanks D. Naish for a constructive review.”

Of course I would have rejected the manuscript for being incomplete. This study does nothing to show us a gradual accumulation of pterosaurian traits. It ignores the findings of pertinent published works and generally makes paleontologists look bad on several levels.  If anyone can defend such a paper, please do so! Tell me how pterosaurs are such good sisters for Erythrosuchus and Proterosuchus.

As always, I encourage readers to see specimens, make observations and come to your own conclusions. Test. Test. And test again.

Evidence and support in the form of nexus, pdf and jpeg files will be sent to all who request additional data.

References
Bennett SC 1996. The phylogenetic position of the Pterosauria within the Archosauromorpha. Zool J Linn Soc. 118:261–309.
Bennett SC 2012. The phylogenetic position of the Pterosauria within the Archosauromorpha re-examined. Historical Biology. iFirst article, 2012, 1–19.
Hone DWE, Benton MJ. 2007. An evaluation of the phylogenetic relationships of the pterosaurs among archosauromorph reptiles. J Syst Paleontol. 5:465–469.
Hone DWE, Benton MJ. 2008. Contrasting supertree and total-evidence methods: the origin of pterosaurs. In: Buffetaut E, Hone DWE, editors. Flugsaurier: pterosaur papers in honour of Peter Wellnhofer. Munich, Germany, p. 35–60, Zitteliana B 28.
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 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 David 2011. A Catalog of Pterosaur Pedes for Trackmaker Identification. Ichnos, 18: 2, 114 —141.

Debunking ReptileEvolution.com? More Bogus Evidence Incoming!

Preamble: I’ll admit that there have been errors on ReptileEvolution.com brought about by a variety of circumstances including inexperience and bad data.  Every effort has been made to fix those problems and dozens have already seen changes made. I found virtually all of them, but others have helped. None of these have affected the topology of the large reptile tree at the center of the site. None of my major issues have, so far, been reversed with evidence coming in from the outside. Even so, I’m still open to the possibility.

Can the traditional guys say the same? Hope so! Haven’t seen it yet, though.

Now Back to our Debunking Topic
Since Darren Naish’s blog urging web surfers, “Why the world has to ignore ReptileEvolution.com” other bloggers have joined in. As scientists we need to explore their arguments to see if they contain validity. It’s important to promote the truth in science. Anything less needs to be corrected. That’s why I’m interested in what these bloggers have to say. Given that, I’m –still– not seeing from them –any– specific arguments that hold water. See if you agree:

Pterosaur.Net wades in against ReptileEvolution.com
Pterosaur.Net is the work of a group of paleontologists who hold that pterosaurs are dinosaur kin, had deep chord wing membranes and were not able to rise to a bipedal configuration. Plus this group holds that pterosaur eggs were buried prior to hatching. and they took off by rebounding off their forelimbs. ReptileEvolution.com and PterosaurHeresies.com have provided more than adequate evidence against all of these bogus ideas. [note that I’m not saying don’t believe anything in Pterosaur.net. It’s important to make that distinction.]

Mark Witton, writing for Pterosaur.Net quoted Darren Naish when he wrote, ReptileEvolution.com does not represent a trustworthy source that people should consult or rely on. Students, amateur researchers and the lay public should be strongly advised to avoid or ignore it.”  Naish and now Witton risk appearing to be a little heavy-handed in their assessment by not recognizing something of value here. We looked at Naish’s bogus arguments earlier. Sorry to see Witton buy into that without critical thinking and good evidence.

Dr. Witton was kind enough to provide what he considered evidence for his arguments with regard to mistakes I made with pterosaurs. I’d like to say that he provided some insights to help correct errors, but alas, he did not. You know, I always ask for anyone who has evidence to the contrary to step forward.

Witton compared my Anurognathus reconstruction to a photograph of another, much smaller pterosaur purported to be Anurognathus (Bennett 2007, Fig. 1), but actually is a distinct genus, with a much flatter skull and many other distinctions. Here Witton could have shown a photograph of the specimen in question.  He chose not to. Here’s how different the two are from one another:

The flat-head pterosaur

Figure 1. The flat-head pterosaur, a private specimen (on the left) attributed by Bennett (2007) to Anurognathus ammoni (on the right).

But let’s go with Witton’s comparison anyway. Witton wrote, “Note the number of phalanges in the wing finger, shape of the skull and long, fibrous tail [in the flat head specimen].” Unfortunately, Witton failed to note that no other anurognathids have only three phalanges on the wing membrane. You can see samples here, here and here. He failed to note that the original Anurognathus preserves a crushed skull that portrays the lateral and dorsal views with palatal elements scattered about and that the flat head pterosaur is preserved strictly in dorsal view. Earlier we discussed and provided evidence for the mistaken interpretations Bennett (2003). By his own admission Bennett was unable to identify several bones. His big gaff: he misinterpreted a maxilla as a gigantic sclerotic ring preserved on edge (which never happens in other fossils).

Bennett’s reconstruction breaks several “rules” that apply to pterosaur morphology. The ReptileEvolution.com tracing identified all the bones. Left and right elements were symmetrical. In the reconstruction all the bones “fit” and none of them broke any morphological “rules.” Rather, every bone looked like bones in other anurognathids, which no one else had ventured or dared to attempt. The eyes were small. The maxillahad tiny teeth.  On the flat head anurognathid, three wing phalanges are indeed exposed on the surface, but as we looked at earlier, there is evidence for more phalanges still buried in the matrix. This problem could be readily solved with just a little more digging. That goes for the tiny, bead-like tail too.

It’s just too bad that anurognathids have not been precisely traced by any other paleontologists. Here’s an example of a good tracing. Other pterosaur workers seem to be content tracing coarse cartoony outlines of only the most readily observable features, as shown here.

Witton continues, “the resultant [phylogenetic] trees are understandably completely incongruous with anything seen in ‘mainstream’ literature.” Of course this makes ReptileEvolution.com look bad. — AND–  exploring untested taxa together is the whole reason for ReptileEvolution.com. To create a tree large enough to test the assumptions of smaller trees. That’s why it is completely incongruous with anything the the mainstream literature.

You want to test the large reptile tree? Go ahead and take out all the controversial reconstructions and you still recover the same tree. I know it works.

What Witton doesn’t tell you is the new pterosaur tree includes many times more specimens than ‘mainstream’ trees, many of which suffer from poor resolution, by their own admission. In other trees, sister taxa do not look like each other (mixing toothy and toothless taxa, for instance). By contrast, the ReptileEvolution.com trees all recover sister taxa that all look like one another, gradual producing derived taxa. After all, isn’t that what we expect from a model echoing the course of evolution?

Witton continues, “he [Peters] retains his ideas in the face of overwhelming evidence to the contrary (i.e. the inability to see the structures he claims to find on actual specimens despite microscopic, and UV observation, and CT scanning). As such, the work portrayed on his website and blog has to be pseudoscience, at best.” Well, here is where Dr. Witton could be most helpful. If he indeed had evidence to the contrary, I would hope that he would present it. Withholding it then complaining about it strikes me as unfair. If he’s referring to published works. To be fair, though, I’ve been just as tough on the guys at Pterosaur.Net, not disbelieving them, but dismantling and disproving their various weird contentions. The pseudoscience is rampant over there! No wonder they’re pointing fingers.

Witton references Hone et al. 2009, a paper that attempted to bash Parallel Interphalangeal Lines (PILs) without success. The rebuttal (Peters 2010) noted how many times Hone et al. (2009) reported that in many taxa PILs could indeed be drawn. In their arguments Hone et al. (2009) did not provide any examples with five or four toes, which is where the best PIL sets are to be found. Even their prime example, a three-toed theropod (Ornithomimus) with flexed toes retained PILs (*see below for comment). Hone et al. 2009 went so far as to provide a set of bogus computer-generated cat toes to demonstrate that PILs could not be drawn between the phalanges. Sensing pseudoscience, Peters (2010) countered with tracings of actual cat feet and paw prints to show complete sets of PILs, despite the extreme flexion and extension in the very derived cat toes. Truly a worst-case scenario that came out smelling like a rose.

pterosaur wing ungual

Figure 2. Pterosaur wing ungual almost articulated to manual 4.4 from an unidentified Chinese pterosaur.

Witton republished a fourth and fifth wing phalanx from an unknown pterosaur and claimed that I invented the ungual. Seems pretty clear to me. More to the point, as I described earlier, I was — not– the first to see the odd curved, hooked tip. That honor goes to David Hone! …another member of Pterosaur.Net! Hone described the oddity as a malformation in his blog here without understanding its significance. Contra Witton’s criticism, wing unguals are actually quite common, if not universal, in pterosaurs. Unfortunately, so often the fragile tip remains buried in the matrix or the ungual becomes dislocated. A careful search usually results in a discovery.

Dr. Witton concludes, “Hence, I urge you to read Darren’s discourse if you have not already done so and, if you are concerned about the accurate portrayal of palaeontological science online, then blog, tweet and discuss this issue as much as you see fit. As may be expected, Peters has started a rebuttal of the piece across a number of blogposts, which begins here.”

So here we are, again, much as in Darren Naish’s blog, with a refusal to “see” what has been described by others, to “see” what is very clear as evidence, and to use disassociated evidence to argue against my work. Heavy-handed? You be the judge.

Argument Styles
Lastly, I want you to note the difference between my approach and that of Witton and Naish. I don’t say, “don’t look at or believe anything on their sites.” I say. “take a closer look at their evidence in specific cases and here’s a reinterpretation based on precise tracings and more expansive analyses.” I know they’re sincere in what they say, but when direct scientific comparisons are not made their arguments come off as prejudice and propoganda, which is not their intention. They don’t even know how bad they sound. I would hope that someday both Witton and Naish would draw attention to a specific problem in ReptileEvolution.com and provide circles and arrows that highlight their arguments. Then we will have something to discuss.

Simply disrespecting an entire website, as if it had no value whatsoever is absurd. Painting me as a lunatic tells us more about them, ironically. Picking apart bogus arguments with facts and evidence is more my cup of tea. Wish it was theirs’.

* Regarding the Ornithomimus pes presented in Hone et al. 2009, I wrote (Peters 2010), “On a similar note, the caption beneath an illustration of a very similar Ornithomimus pes (Hone et al. 2009, figure 4) complains that ‘only three possible hinge lines can be drawn’, and this is despite the fact that the toes are shown unnaturally parallel (recovery stroke configuration) rather than radiating in use as theropod ichnites otherwise indicate. Fewer toes mean fewer lines. That was spelled out in Peters (2000a). Still, it is a testimony to the HLH (=”Hinge Line Hypothesis according to Hone et al. 2009) that Hone et al. (2009) were able to find hinge lines despite deforming a three-toed foot. It is also a testimony to the HLH that Hone et al. (2009) were unable to show any manus or pes in which PILs could not be drawn, no matter  the number of fingers and toes. If they were to someday attempt another attack on Peters (2000a), such evidence would be required.”

References
Bennett SC 2007. A second specimen of the pterosaur Anurognathus ammoni. Paläontologische Zeitschrift 81(4):376-398.
Hone DWE, Sullivan C and Bennett SC 2009. Interpreting the autopodia of tetrapods: interphalangeal lines hinge on too many assumptions. Historical Biology, iFirst article, 2009, 1–11, doi: 10.1080/08912960903154503.
Peters D 2010. In defence of parallel interphalangeal lines. Historical Biology iFirst article, 2010, 1–6 DOI: 10.1080/08912961003663500

How Nyctosaurus UNSM93000 lost a wing phalanx, or two.

There is no doubt that the UNSM 93000 specimen of Nyctosaurus (Figs. 1, 2, Brown 1978, 1986) had three wing phalanges (not counting the hypothetical vestigial ungual perhaps still buried in the matrix, insufficiently excavated to reveal the possibility). All other pterosaurs have four wing phalanges, plus the ungual.

Cast of the UNSM93000 specimen of Nyctosaurus

Figure 3. Cast of the UNSM93000 specimen of Nyctosaurus (hanging in my office and taken by cellphone). Wing phalanges marked. The identity of the wing phalanges appears to be m4.1, m4.2 and m4.4 (curved). There is no vestige or indication of m4.3. Arrows point to joints and the extensor tendon process.

Due to this specimen, traditional thinking holds that all Nyctosaurus specimens had but three wing phalanges, having lost the fourth phalanx. We’ll test that paradigm today.

The UNSM specimen of Nyctosaurus

Figure 2. The UNSM specimen of Nyctosaurus, the only one for which we are sure it had only three wing phalanges.

Contra traditional thinking
I found four wing phalanges on the more basal nyctosaurs like the Field Museum specimen FMNH 25026 (Fig. 3) and the Fort Hays specimen, FHSM VP21 (Fig. 4). The more derived crested specimen, KJ2 has a split and shattered wing phalanx 2/3, so I can’t determine its status from available data. Its reconstructed length and phylogenetic nesting strongly suggests that m4.3 is simply missing. It never developed.

The Field Museum Nyctosaurus, FMNHVP21,

Figure 3. The Field Museum Nyctosaurus, FMNHVP21, with color overlays identifying the wing phalanges of one wing. Four are present. Only the proximal knuckle and distal third of m4.3 is preserved.

The Fort Hays specimen of Nyctosaurus, FHSM VP2148

Figure 4. The Fort Hays specimen of Nyctosaurus, FHSM VP2148 identifying all four wing phalanges and the extensor tendon process (ETP). The rostral crest is made of putty. Another unidentified curved m4.4 is beneath the distal end of the upper m4.1.

So what happened to the missing phalanx?
In the UNSM93000 specimen (Figs. 1, 2) m4.2 is roughly 85% of m4.1, which is similar in proportion to m4.2 in the other nyctosaurs. Manual 4.3 appears to be unreduced in the Field Museum specimen.  Manual 4.3 is relatively shorter in the Fort Hays specimen, but still substantial. In all Nyctosaurus manual 4.4 is curved and shorter than the other phalanges, and that pattern in followed in UNSM 93000, Thus it does not appear that manual 4.4 withered and disappeared in UNSM 93000.

No, something else happened to m4.3.
Manual 4.3 does not appear to have fused to m4.2. That would have made an elongated wing phalanx and finger. There are no marks on the middle phalanx to that effect. Rather, all the other bones are much the same as in other nyctosaurs. It seems that m4.3 simply did not appear, did not develop. Very strange.

If the ungual of UNSM 93000 turns out to be missing (after further excavation) I would not be surprised. I’m sure it could have happened on the most derived Cretaceous pterosaurs. Especially one that was losing m4.3! A vestige can only last so long, but this specimen needs just a little bit more excavation to find out.

As always, I encourage readers to see specimens, make observations and come to your own conclusions. Test. Test. And test again.

Evidence and support in the form of nexus, pdf and jpeg files will be sent to all who request additional data.

References
Brown GW 1978. Preliminary report on an articulated specimen of Pteranodon Nyctosaurusgracilis. Proceedings of the Nebraska Academy of Science 88: 39.
Brown GW 1986. Reassessment of Nyctosaurus: new wings for an old pterosaur. Proceedings of the Nebraska Academy of Science 96: 47.

wiki/Nyctosaurus