and Tetrapod Zoology – part 3

Earlier (here and here) I responded to the first parts of the Tetrapod Zoology criticism of Here is part 3, all about my run-ins with Sordes and Cosesaurus.

Figure 1. Sordes interpreted by me in Nature 1995. At that time. remember, no one had ever heard of a uropatagium, separate uroptagia, yes.  And the purported “fact” that this flap of skin spanned the hind limbs without connecting to the tail seemed pretty hard to swallow for a majority of paleontologists. The only images available were small and indistinct. Even so, an attempt was made here to understand the taphonomy of the specimen and how it came to sport such a strange autapomorphy that has not been seen since on any pterosaur fossil. Despite the sincerity of this effort, it includes several mistakes rectified now in  traced from a recent publication of the specimen in a larger format with higher resolution.

Darren Naish picks up with a 1995 criticism of my first published work, which happened to be in Nature, as I reconstructed Sordes pilosus prior to the apparent drifting of the elements (Fig. 1). Admittedly sophomoric. The work was crude and based on crappy photographs, but at its core was more or less correct. The left forelimb had drifted, as shown here in photographic detail. The wing membranes had a narrower chord than others had imagined. The myth of the purported “uropatagium” in Sordes is detailed here in and here.

Uropatagium of Sordes according to Sharov 1971 and Unwin/Bakhurina 1994.

Figure 2. Uropatagium of Sordes according to Sharov 1971 (above) and Unwin/Bakhurina 1994 (below). Color and captions added by me.

At left are the only two images of Sordes published before my Nature paper. Note the Unwin/Bakhurina (1994) image omits many of the details found in the earlier Sharov (1971) paper. So really, what was gained? Darren wrote of my Nature drawings (Fig. 1), “This is a speculation based entirely on examination of published photos. It cannot be considered anywhere near as reliable as Unwin & Bakhurina’s examination of the actual fossil.” Of course this is speculation. It’s an idea, an explanation for a weird phenomenon. Science permits such speculation because Science likes ideas. (How did the rings of Saturn form? Do continents really drift?) I still haven’t seen the Sordes specimen, but I have found in the specimen (here in overlooked bones that explain why the mass of wing membrane is where it shouldn’t be.

With regard to the uropatagium
All other pterosaurs (and fenestrasaurs) have twin uropatagia that span the area behind each knee, arcing to the pelvis and heel. So how does one explain the anomaly of a single uropagagium in Sordes? Now I think the material between the feet of Sordes includes unattached wing membranes carried there by disarticulated and drifted forearm elements as shown here. The paired uropatagia are smaller and less distinct, but still visibile here. If there is a better explanation out there, I’d like to see it. Remember, this is only an idea and Science likes ideas. As you can tell by the Unwin and Bakhurina (1994) drawing, attention to detail was not their strong point.

If you want reliability, don’t take my word for it. Don’t take their word for it. Take a look at the specimen yourself using all the published materials as your guides. Science is all about repeatability, not taking someone’s word for it, but testing it youself. Unwin and Bakhurina (1994) provided their interpretation. I provided another. Nothing to raise hackles about.

Cosesaurus and the Rivisita Italiana Paper
Darren reports he was initially impressed by my paper on pterosaur origins (Peters 2000b) noting that I had reconstructed elements of Longisquama and Sharovipteryx with more detail than prior workers (which means only Sharov’s (1970, 1971 short papers and small illustrations). With regard to Cosesaurus a great deal of detailed work was earlier provided Ellenberger (1978, 1991). All three of these specimens were examined personally and under the microscope — and even so, I made mistakes due to my lack of experience. Darren reports that despite his initial enthusiasm for the results, “[others] were far from enthusiastic; the overwhelming opinion being (1) that you just couldn’t see the things reported in that paper in real life (that is, the interpretations were in error), and (2) that the phylogenetic analyses included in the paper were completely erroneous, since they wholly relied on those problematic observations (in the paper.,”

In order to get that paper (and all my many others) published it had to pass peer review. And it passed. More to the point, you’ll note that once again critics are painting my work with the broadest of brushes, dismissing my direct observations (using established paleontological techniques) without providing alternative observations that could then be considered side-by-side for comparison. Here’s a fact that you can look up: Dr. Paul Ellenberger (1978, 1993) saw all of the items that I saw in Cosesaurus, only our interpretations differed, which I covered earlier here and here. He correctly identified the strap-like, bird-like scapula which I dismissed because I had the prolacertiform bias (since corrected here.) He correctly traced two wrist bones outside of the wrist, which I earlier ignored then later realized they were the pteroid and preaxial carpal. The list goes on (see more here). Oddly, no one has made a serious attempt at reconstructing the skeletons of the basal fenestrasaurs since my work in 2000, despite the importance and despite their dismissals (“step aside and let a REAL paleontologist look at that specimen!). Wonder why that is? Wouldn’t it be awful is someone actually confirmed our (Ellenberger and myself) observations? It would literally bring down the house.

Pterosaurs and Dinosaurs
Darren continues by reiterating traditional thinking, “other workers have continued to find support for a close affinity between pterosaurs and dinosaurs (e.g., Brusatte et al. 2010, Nesbitt 2011, Butler et al. 2011), and they’ve ignored the results and proposals of Peters (2000).” You’ll note in none of these papers do these workers test the fenestrasaurs in their matrices to see what would happen. They don’t even look at them. For some reason they are content to simply stay the course. Darren reports, “It’s because his [meaning my] observations, and hence his character codings and the trees that result from them, are regarded as wholly unreliable.” Fine! Then create your OWN observations and character codings! What’s wrong with that? There should no “trust” in Science as there is in Religion.  There should only be testing! No reliability! Only skepticism! In 2000 I simply suggested an alternative. It really is up to others to repeat the experiment, but so far others have refrained from doing so.

Darren continues, “Remember that the workers who produce the trees that support the ‘conventional’ view of pterosaur affinities have spent a lot of time looking at actual fossils.” As if I haven’t (see above). He continues, “Furthermore, these researchers have done an excellent job of explaining and documenting the characters they use in their phylogenies, and they have proven track records of showing that they understand how to reconstruct phylogeny and analyse phylogenetic data.” And that’s why they can’t explain how pterosaurs suddenly appeared in the fossil record without apparent antecedents. And that’s why they can’t explain why Vancleavea has no antorbital fenestra or mandibular fenestra despite claims that it is an archosauriform. Etc. etc.

Let’s also remember that in that landmark pair of papers by Hone and Benton (2007, 2009) they didn’t even look at the specimens in question and discarded two of them outright (Longisquama and Sharovipteryx) while only retaining a quarter of the characters for Cosesaurus. This is how the battle has been waged: ignore the specimens, attack the methods, dismiss the wise guy in St. Louis, don’t upset the status quo. It’s a sad state of affairs in paleontology if this is really what it has come to.

Hopefully someday Darren will reexamine Hone and Benton (2007, 2009) with the same vigor and find out why these two PhDs didn’t notice that their supertree could not nest Choristodera with the choristorderes Champsosaurus, Cteniogenys and Lazarusuchus. And it failed to nest Lepidosauromorpha with the lepidosaurs, Gephyrosaurus, Sphenodontia and Squamata and more errors detailed here. They found that Cosesaurus nested next to Proterosuchus, for instance. Crazy results slipping past everyone’s radar…

Next up: the Longisquama Controversy

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.
Ellenberger P 1978. L’Origine des Oiseaux. Historique et méthodes nouvelles. Les problémes des Archaeornithes. La venue au jour de Cosesaurus aviceps (Muschelkalk supérieur) in Aspects Modernes des Recherches sur l’Evolution. In Bons, J. (ed.) Compt Ren. Coll. Montpellier12-16 Sept. 1977. Vol. 1. Montpellier, Mém. Trav. Ecole Prat. Hautes Etudes, De l’Institut de Montpellier 4: 89-117.
Ellenberger P 1993. Cosesaurus aviceps . Vertébré aviforme du Trias Moyen de Catalogne. Étude descriptive et comparative. Mémoire Avec le concours de l’École Pratique des Hautes Etudes. Laboratorie de Paléontologie des Vertébrés. Univ. Sci. Tech. Languedoc, Montpellier (France). Pp. 1-664.
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. PDF online
Hone DWE and Benton MJ 2009. Contrasting supertree and total-evidence methods: the origin of the pterosaurs. In: Hone DWE, Buffetaut E, editors. Flugsaurier: pterosaur papers in honour of Peter Wellnhofer. Vol. 28. Munich: Zittel B. p. 35-60.
Peters D 2000a. Description and Interpretation of Interphalangeal Lines in Tetrapods. Ichnos 7:11-41.
Peters D 2000b. A reexamination of four prolacertiforms with implications for pterosaur phylogenesis. Rivista Italiana di Paleontologia e Stratigrafia 106: 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
Sharov AG 1970. A peculiar reptile from the lower Triassic of Fergana. Paleontologiceskij Zurnal (1): 127–130.
Sharov AG 1971. New flying reptiles from the Mesozoic of Kazakhstan and Kirghizia. – Transactions of the Paleontological Institute, Akademia Nauk, USSR, Moscow, 130: 104–113.
Unwin DM and Bakhurina NN 1994. Sordes pilosus and the nature of the pterosaur flight apparatus. Nature 371: 62-64.

Tetrapod Zoology

6 thoughts on “ and Tetrapod Zoology – part 3

  1. I have to say as a photographer and some one with a degree in palaeobiology I find this whole looking at just the photos, even high res ones, and not the actual specimen a bit iffy. A whole heap of things can happen as you take the photo and as your process them digitally that create artefacts, something that could be interpreted as bone etc. That is before you take into account things like marks made in preparation or fragments of wood not fully prepared and creating an impression on the surface. You can not be certain what you are looking at with having the specimen in front of you.

    In fact you say:
    “If you want reliability, don’t take my word for it. Don’t take their word for it. Take a look at the specimen yourself….” – good advice I politely suggest you practise yourself

    You also said:

    “Of course this is speculation. It’s an idea, an explanation for a weird phenomenon. Science permits such speculation because Science likes ideas”

    Of course science likes ideas, but not when they are portrayed as absolute fact, as they are on your website and other conclusions and reconstructions based on the work of many other peer reviewed workers using peer review evidence are dismissed as nonsense….

    • Neil, I do give credit where credit is due. Criticism comes and goes. To your other point, I have seen hundreds of specimens and dozens of museums on three continents. Some of Darren’s comments were not true, but continue to be part of the mythology that has grown around my work.

      • So in you method how do you account for the possible problems from using photos and manipulating them in post processing and the artefacts that may form, giving the impression of bones or soft tissue that are not there?

        So have you seen all the specimens you have used your method on then? I still think its risky to based a reconstruction on just a photo, especially if it is one that contradicts what someone with the specimen in front of them has seen. Do you take into account the preparation of each specimen too as what appears to be soft tissue in a photograph could just be preparation marks.

        The thing that confuses me is that you are seeing things that others cannot see with the specimens in front of them

  2. Understood. Common problem. You should know: 1) I’m not always right. 2) They’re not always right, or cover all the bases.

    I have not seen ALL the specimens I have portrayed. Even seeing the specimen, many people, including me, make mistakes. Nothing is foolproof.

    Look for the Bellubrunnus material coming soon. And please examine all of the roll-overs in to judge for yourself.


  3. Hone & Benton (2007) is a supermatrix that has been rightly trounced on the DML. It is very lazy work that should hardly be considered a phylogenetic analysis.

  4. Pingback: Over het ontstaan van kikkers, slangen, krokodillen | Tsjok's blog

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