The Pterosaurs of Rio


Last week was Pterosaur Week in Rio de Janerio, Brazil (Brasíl) at the International Symposium on Pterosaurs, held by the Museu Nacional in Rio.logo_rioptero2013Here, dozens of the brightest among pterosaur workers joined to share new data and old ideas cast in new light (in some cases, literally) on those strange, flying reptiles. I participated in two presentations with Hebert Bruno Campos, but through the vagaries of life, could not participate; and unfortunately, neither could Hebert, who also missed out on a presentation on interactive, scientifically-informed digital reconstructions in pterosaurs. It was our intention to present two posters, with an additional poster of Hebert’s with Anthony Maltese, but that could not happen.

Instead, what I have to share are the posters I prepared, which contain the entire text of the extended, long abstracts submitted, reviewed and accepted by the symposium organizers. Yes, the abstracts for the Rio symposium were reviewed, in much the same manner though with less demand for details as would a normal paper. My normal reluctance to discuss abstracts will be set aside as I present, here, these posters. It is my intention to use this as an opportunity to drum up reactions and discussion, which normally would happen while I was attending the abstracts and sessions at the meeting. Feel free to comment at length!

JPoster2 smCampos, H. B. N., Headden, J. A. & Frey, E. 2013. New material of the enigmatic ornithocheiroid Cearadactylus atrox from the Santana Formation (Lower Cretaceous), northwestern Brazil. International Symposium on Pterosaurs, Rio de Janeiro, Brazil, 23-26 May, 2013. Museu Nacional, Museu de Ciências da Terra, Rio de Janeiro, Brazil.

First up, a skull of an ornithocheiroid pterosaur in the SMNK of Karlsruhe, Germany, appears to belong to Cearadactylus atrox. This specimen is much larger than the holotype specimen, and suggests the holotype is a subadult or juvenile. This is a conservative referral, but relates to the holotype jaw in its slenderness, shallow rostrum, slight rostral crest, and proportion of the nasoantorbital fenestra. But there’s also a new, more complete mandible. We point to new features that help diagnose Cearadactylus atrox, but also that the jaw material presents features of so-called “lonchodectids” (a group of pterosaurs associated on the basis of a few features of the palate and mandibular symphysis, but never formally named) but more derived, ornithocheirid/anhanguerid pterosaurs. We suggest that “lonchodectids” are a polyphyletic association — more of a grade, really — an association not aided by the fact that the material comprises partial jaws of limited phylogenetic information.

JPoster smCampos, H. B. N. & Headden, J. A. 2013. A review of Tupuxuara deliradamus (Pterosauria, Azhdarchoidea, Thalassodromidae) from the Early Cretaceous Romualdo Formation of Brazil. International Symposium on Pterosaurs, Rio de Janeiro, Brazil, 23-26 May, 2013. Museu Nacional, Museu de Ciências da Terra, Rio de Janeiro, Brazil.

Second up, the Kanagawa skull of Tupuxuara. Mark Witton discussed this skull in part in 2009 when describing a new species of Tupuxuara, deliradamus, and suggested this specimen could be referred to his new species. We agree, but consider that the issue of what specimens can be referred to Tupuxuara may be trickier than seen, especially given previous authors’ arguments about Tupuxuara leonardii and longicristatus, the holotypes of which are small fragments of the pre-nasoantorbital snout — regions missing in the Kanagawa skull. Nonetheless, the specimen adds new diagnostic information for deliradamus, and further provides interesting suggestions for cervicocranial anatomy, including large anchor sites for several interesting muscles. A mandible is associated with the specimen, but it seems the jaw, which is complete, belongs to a different specimen as it is wider across the articulars than the skull is across the quadrates, and this doesn’t seem to be influenced by distortion in either specimen. Thus, the Kanagawa skull represents two different thalassodromid skulls.

These studies are part of a larger project, and I’ve quite enjoyed the work I’ve been doing on them. There is, obviously, much more to be said, and we tried to stuff what we could into these abstracts for all that we were confined to 3 pages of text with figures and references, rather than the few-odd paragraphs typical for abstract books. That also makes these closer to short form papers, though without the data to back them up they are still abstracts. Nonetheless, now that they are out there, we (my coauthors and I) hope to receive the feedback we missed in Rio.

About these ads
This entry was posted in Paleobiology, Paleontology and tagged , , , , . Bookmark the permalink.

6 Responses to The Pterosaurs of Rio

  1. Jaime, can you make pdf files available? Dave

    • PDF versions of the abstract book were not produced; I am receiving a physical copy, and will check this against my prepared files then post those when I can compare them.

  2. Mark Witton says:

    Nice looking poster on Tu. deliradamus, and it’s good that some additional features have been found to support its distinction from other thalassodromids. I’m not sure I agree with the 7th character (bone texture is always a little tricky to play with, considering its vulnerability to weathering and ontogenetic effects). More pressingly however, your text doesn’t really reflect the current state of play with thalassodromid specimens or their treatment in published works. The result is that a lot of what you present as ‘new’ here is actually not, and some of what you’ve said is just plain inaccurate. I apologise if this comes across as a rant, but I spent much of my PhD looking into and publishing on the taxonomy of azhdarchoids (with a big focus on thalassodromids), so seeing this science being presented inaccurately erks me no end.

    Firstly, KPMNH DL 84 was very clearly referred to Tupuxuara deliradamus in 2009. It has never, to my knowledge, been referred to Tu. sp. Veldmeijer (2006) referred it to Tu. leonardii, but this is the only referral of this specimen I know of outside of my own work. My 2009 paper pointed out KPMNH DL 84 represents a large, possibly adult version of Tu. deliradamus after noting its shared morphology with SMNK PAL 6410. The retention of the angular posterior NAOF margin and other features strengthened the diagnosis of this species, showing they were retained throughout ontogeny. There was so much of this embedded in my paper that I’m surprised you missed it all. The specimen was discussed frequently as a member of deliradamus, illustrated it in lateral view in two figures, labelled as Tu. deliradamus in both, and listed as ‘referred material’ to Tu. deliradamus in the ‘Systematic Palaeontology’ section. I don’t think I could have made my opinions on it clearer! This does mean, though, that KPMNH DL 84 is not really ‘a new specimen’ at all: it’s already been discussed, figured and reliably referred to an existing taxon. Equally, the possibility that Tu. deliradamus may represent an existing thalassodromid taxon – specifically Tu. longicristatus because we know what the posterior skulls of Thalassodromeus and Tu. leornadii look like – was mentioned in the 2009 paper.

    Secondly, I referred IMCF 1052 to Tu. leonardii in Witton (2009) and Martill and Witton (2008), following others (e.g. Unwin 2003; Kellner 2003, 2004; Veldmeijer 2006; Kellner and Campos 2007). Again, this was mentioned in text and made explicit with two figures. There is no uncertainty among pterosaur workers about the identity of this skull.

    Finally, SMNK PAL 4330. I considered Tu. leonardii in 2009 after Martill and I added a postscript to our 2008 paper (the one describing SMNK PAL 4330) which specifically discussed its palatal morphology following further preparation. We noted that it had the same diagnostic palatal morphology as Tu. leornardii. Based on my observation of the specimen, I am unsure where your suggestion that the palatal ridge of this specimen was ‘shallower than Tu. longicristatus’ comes from. The anterior premaxillae of SMNK PAL 4330 lacks a midline prominence and is concave along its surface, but a clear midline ridge emerges posteriorly, just as it does in other specimens of Tu. leonardii. Given that the rest of the skull also matches Tu. leonardii, there is no doubt in my mind about the referral of SMNK PAL 4330 to this species.

    In sum, I’m not quite sure where you got your information from for this poster, but there are some serious oversights in fact checking here. On a related note, I do have my own review of thalassodromids which will condense all my thoughts on their taxonomy into a single place, but it’s waiting to go into a multi-author volume which, unfortunately, is currently going through some teething problems. Hopefully it will be published before too long.

    • I’m going to tackle this in order. Needless to say, the rhetoric doesn’t put me in a very conversational frame of mind.

      1. I will admit to using strong language. That is, “new” and such. This abstract was meant to grab the eye, hence the structure of the terminology. It is not a paper. Admittedly, this might seem that portions of it are misleading, but, as you will see…

      2. Referral was not certain. This specimen has not been described in any way. When reviewing the literature on the specimens referred to and bandied about as Tupuxuara this or that, KPMNH DL 84 has, along with IMCF 1502, been on the “suggestion” block; this is despite your more certain statements, but we have some difficulties with that…

      3. Much of this, in fact, has to do with the assumptions about IMCF 1502 and SMNK PAL 4330, especially their relation to the the conservation of marphology and their applicability to described species. Holotypes of leonardii and longicristatus are extremely partial, to which other specimens (KPMNH DL 84 included) cannot be reliably referred. The pre-NAOF section in SMNK PAL 4330 is too badly preserved and partial (and is even reconstructed as partial in Martill & Naish) to permit support for its referral to any species of Tupuxuara on the basis of palatal morphology. The assumption that it does, or can, is based on the assumption that the ventral margin of the snout is intact, but this is asserted and not demonstrated. The influence of ontogeny is a trickery one, especially as concerns the shape of the NAOF through time and the position of the orbit as the skull grows, neither of which have been previously constrained in azhdarchoid taxa due to the typical paucity of specimens referrable to most taxa (obviously, “Quetzalcoatlus sp.” is an exception, but those skulls have not been fully described). You seem to also think the specimen association with Tupuxuara longicristatus and leonardii are settled. We disagree.

      4. My coauthor and I are taking this to the next level, by evaluating KPMNH DL 84 and the morphological bases for referral to various taxa, which based on published discussion is severely lacking, and those specimens being referred to various taxa. Initially, it was to assess the diagnostic value of the specimen, regardless of the species, and to determine whether various characters, such as the surficial striation of the crest surface (and nowhere else) was valuable — it was one of the last features to be added to list, I’ll grant you, we are not 100% certain of its value, but it is a differentiable character. This transformed into a question of whether we could agree with Witton (2009) on the basis of referral or, that instead the specimen might be useful on its own, or the question was not firmly resolved; we opted to accept the referral that was made with the caveats that specimen relation to taxon in Tupuxuara spp. is tricky and based on some broad asusmptions, including how neither deliradamus specimen preserves the snout. I will further note that one possible conclusion we had was to separate this specimen, given the “number of autapomorphies” definition of a taxon (a rather rampant one), into a new binomen, and making deliradamus not a subset, but a sister taxon to Tupuxuara etc. It is apparently that a more attractive option in pterosaur systematics is to simply coin a new binomen off the bat instead of referring species to previously established “genera,” or to use locale as a demonstration of taxic “specialness” worthy of taxonomic nomenclature. We avoided this; ours is the conservative option. We would have said much less about Witton (2009) than we did had we chosen this option, and you might not have as much of an issue with the abstract/poster this way.

      You will probably have your views on the taxonomy published before this, maybe or maybe not, but rest assured I will pass our manuscript by you for comments. I will reiterate that what we presented in the poster and the abstract are practically dataless: You’ve not seen, nor did you ask for, our more in-depth arguments.

      • Mark Witton says:

        On your points…

        1. “It’s not a paper”

        Does that matter? If you’re putting ideas out there, you’re putting them out there. Besides, it’s now also a blog post. The audience for this is potentially the internet using world.

        2. There’s clearly a difference in philosophy here. Even though IMCF 1052 and KMPNH DL 84 haven’t been described, I don’t count their referrals as being on ‘the suggestion block’. They have both been referred to specific taxa, and, as since their referrals have not been challenged, that should be considered and mentioned as their current taxonomic home until evidence is presented to suggest otherwise (note that Martill has publicly stated that he probably erred with the notion of a single thalassodromid species [as per Martill and Naish 2006], so the identification of IMCF 1052 should be considered unchallenged in current literature). I’m a bit put out by the fact that I discussed the identification of these specimens at length in my own work and that has gone unmentioned here, while you claim to have broke new ground. Well, sorry, but you didn’t. I’m not saying there’s nothing novel here – there’s some new anatomical information about KMPNH DL 84, possible enhancement of its diagnosis and your own voice about thalassodromid taxonomy – but idea of the specimen being novel and newly identified is not accurate.

        3. We’ll have to disagree about the utility of the Tupuxuara holotypes. I once, like you, thought they were all pretty useless, but then realised that they were better than I first thought. I’m very confident about the ventral premaxillary surface of SMNK 4330 because I prepped out the ventral side of the rostrum and saw it myself, and am OK with our referral to Tu. leonardii. The anatomy is really so similar that they are almost certainly the same thing. The rest of the skull fits that animal fine in my view, too. Even if SMNK PAL 4330 is something else, it isn’t longicristatus because the ventral rostrum is concave, not convex, and lacks a ridge along its anterior surface. As for ontogeny, the current taxonomy fits the available data OK too (SMNK PAL 6410 maintains its depressed orbital morphology and inclination through growth into a animal twice its size [KMPNH DL 84], as does the known posterior skull in Tu. leonardii, seen in the diminutive SMNK PAL 4330 and much larger IMCF 1052). There could be all sorts of weird things taking place as these animals grow, but that’s not what the current data seems to be saying.

        4. Part of my PhD, awaiting to be published in that aforementioned MS sitting in development Hell, included rediagnosing thalassodromid species and genera, which is perhaps why I’m more comfortable with the taxonomic situation than you. I agree that the existing literature is wanting though (although, again, it’s not as useless as I once thought).

        “you might not have as much of an issue with the abstract/poster this way.”

        Again, the fact that it’s an abstract or poster doesn’t matter. What does is that the work is framed in the correct context, and I don’t think that what has happened here.

        • 1. The abstract/poster is not designed to be data: Indeed, it presents virtually none. What it is designed — what they are ALL designed — is gateways to discussion. Evaluation of these pieces on their own as if they were papers (which contain the data that supports the contentions within) becomes much, much trickier. This is one of the reasons conference proceedings and abstract books are generally not regarded as viable platforms for scientific discourse. Instead, we submitted these abstracts for the purpose of enticing conversation: They are not at this point prepared for publication, and the data that is used to support what is said in them is not complete. That is why I am trying to drum up the discussion here. That is, there is an implicit caveat that these are not papers, despite being “out there.” As Mike Taylor has said to me numerous times, it is better at the least to have the arguments and what meager things I can say out there and develop them than have them sit on my computer. Better that I discuss them openly, freely, than to clutch them to my chest as though they were precious gold. This would be no different than had Hebert been able to discuss them at Rio.

          2. A specimen without description provides no other person a method to evaluate the specimen and your reasoning. If we describe this specimen, and find that it doesn’t match your previous arguments about what it represents, what value does your original nondescription provide? This is especially important because KPMNH DL 84 is far, far more complete than SMNK PAL 4330; if you had access to this specimen to discuss to the point of referral, why not describe it? The specimen is not described, it is impossible to evaluate your decisions, especially given the size of the published illustrations and the lack of photographic data for a specimen of this quality.

          3. You misrepresent my argument to suggest I think they are “pretty useless.” I do not. Rather, I place a far less complete specimen in the perspective that what it says is limited to what IT says. Each of these holotype specimens is limited in its breadth of information, which are exceeded without overlap. My blog is replete with discussions of referring specimens with diagnostic value to species when there are no overlapping material. Holotype is a vertebra? Let’s refer a humerus! When dealing with complex taxic assemblages like the Romualdo and Crato Formations, this is even more problematic because it fails to recognize that multiple species can share similar palatal morphologies.

          BTW, thanks for replying to this blog; having the discussion is better than NOT.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s