Archive for the 'Pterosaurs' Category

Welcome Cryodrakon – a giant Canadian azhdarchid pterosaur

Life reconstruction of Cryodrakon boreas. Artwork by David Maas, used with permission.

A few years ago Mike Habib invited me to collaborate on a paper looking at the anatomy of the exceptionally well preserved humerus of an azhdarchid pterosaur from Dinosaur Provincial Park in Alberta. This specimen is well known as it is a partial skeleton and includes a tibia with bite marks and even a shed tooth from a small theropod. It, and a number of other pterosaur bits from the park were described in the famous Dinosaur Park book from the early 2000s and were tentatively refereed to Quetzalcoatlus. Intending to use both this and soem Quetz material for his study, Mike asked me to look at the material and add something on the taxonomy to make sure this really was the same thing and if not, see if we could say anything meaningful about it’s identity. I got about 6000 words into a draft before I realised that this was in now way a subsection of a paper on mechanics and anatomy and this was going to have to be it’s own entity. Fast forward a couple of years and here is the newly named and distinct Cryodrakon boreas.

Mid cervical vertebra of Cryodrakon boreas, nicknamed the teddybear for obvious reasons.

The name means the ‘frozen dragon of the north wind’ is clearly an azhdarchid pterosaur. We’ve recently found that not all of these animals had super long necks and some were rather short and robust-necked animals. Cryodrakon is certainly one of the longer-necked ones, but it’s vertebrae do seem to be shorter and wider than comparable Quetz vertebrae suggesting that it had a more robust neck than it’s more famous cousin. It’s humerus is also a little less robust than the Texan so presumably it’s ecology was a little different too given how important this element is for walking, take-off and flight.

There’s a fair bit of material known too. The holotype has a humerus, midcervical, pteroid, tibia, rib and wing metacrapl all well preserved (amazing for an azhdarchid) and represent a juvenile of about 5 m wingspan. There’s a lot of bits including lots of isolated cervicals of animals of various sizes right down to things of perhaps 1.5 m wingspan and one huge and fragmentary vertebra that we estimate would represent an anuld in the 10 m wingspan realm. So at adult this would be an aniaml approaching or comparable to the other biggest azhdarchids known. The fact we have so much material is a real bonus as we’re able to show that essentailly all the vertebrae have a unifying set of features so we can infer that even young animals have the same features as adults and we can unify them as a single species. There could be more here of course (it’s hard to say too much about things like an isolated partial scapulocoracoid of soem of the very crushed vertebae) but for now the best interepretation is that there’s one species represented by lots of specimens.

Life reconstruction of Cryodrakon boreas. Artwrok by David Maas, used with permission.

My thanks also to David Maas for his beautiful artwork which he did at short notice to help show off the animal (he retains the copyright, these are used with permission). The colours are supposed to be a bit of fun and obviously echo the Canadian flag but are also not implausible given how little we know about pterosaur colours and the bright patterns we have for at least some very large modern birds. Equally the environment it primarily lived in was subtropical but it’s also likely it would have seen snow on occasion and certainly would have seen the northern lights, but the name primarily refers to the Albertan winter.

Hone, David; Habib, Michael; Therrien, Francois.  2019. Cryodrakon boreas gen. et sp. nov. a Late Cretaceous Canadian azhdarchid pterosaur’. Journal of Vertebrate Paleontology.  DOI: 10.1080/02724634.2019.1649681

The problem with floating pterosaurs

A few years ago I published a neat little paper with Don Henderson on the possible posture pterosaur might adopt in water. This was done to try and see if they might have issues if they became stranded on the surface and especially if the head was left at or even under the surface (you can read about this in some more detail here). However, what I want to talk about in this post is how badly and how often this simple paper seems to have been misinterpreted. I’ve been thinking about this for a while but Heinrich Mallison has just linked to an old post on his blog making the same general point about accuracy of citations. Like him, I’m sure I’m not blameless and we all make mistakes occasionally and cite the wrong paper or misattribute a source or get some details wrong. It happens and while obviously not ideal, such is life. However, some papers more than others seem to suffer from this and the floating pterosaur paper is one of them.

It is only a short paper, under 10 pages long and there’s lots of figures and references in that too and the subject itself is fairly simple so one would hope to minimise confusion. Unfortunately, this seems not to be the case and it’s already acquired a number of citations and comments that at best miss the point and at worst say the direct opposite of a point we made. Below are some direct quotes from papers and then points or quotes from the original paper to show how these are quite incorrect. I won’t directly name and shame the perpetrators as the point here is intended to be illustrative of the problem rather than go after colleagues when I can’t rule out having made the same mistake myself somewhere.

First off our study was apparently carried out in order to ‘imitate the swimming strokes of pterosaurs’. In the title and throughout the paper we refer to the floating posture and talk about static posture in water, not swimming per se. While in the discussion we did refer to the posture some pterosaurs took in water and pointed to how it matches putative swimming tracks, this was clearly not the aim of the paper. That makes this point a bit wide of the mark, but not bad and a rejig of the phrasing would clear this up.

Next up, we apparently show that ‘pterosaurs would not have been able to float without tipping over’. That’s clearly not correct as can be seen from the figures (see below). We do discuss the issue of tipping forwards in pterodactyloids in some postures, and the heads are indeed low, but that’s not the same as saying that all pterosaurs did this all the time and indeed the pterosaurs were generally stable.

Hypothesised floating postures fo various pterosaurs

Moving onto some greater issues, we apparently state that the ‘hairlike pycno-fibers covering their body would likely not trap a layer of air, as feathers of birds, and could become water-logged’. That’s very clearly not what we say at all as we make the very clear statement that ‘the effect of such a coat may have been positive (trapped air increasing buoyancy) or negative (waterlogged).’. Yes it may have been an issue, but we don’t know and are equally open to the possibility it could assist buoyancy and we point to the fur on aquatic mammals as a possible analogy, so this quote clearly is not in line with our position on what effect pycnofibers might have had.

We also are cited for the point that pterosaurs were ‘unable to take off from the surface’. This is not a point we really address (since it’s not directly related to floating posture’ but even in the abstract we say that pterosaurs ‘if immersed would need to take off again rapidly’ which clearly implies we are happy with the idea of water launched and later on we cite Habib and Cunningham and saying ‘A recent study suggests that even the biggest pterosaurs might be capable of taking off from the surface of the water’. In short we’re clearly happy with the idea they could take off from water and while we discuss the possibility that some pterosaurs might not have been able to, at no point do we say that they could not.

Then we have this very problematic statement that ‘simulations of the buoyancy of pterosaurs made using computers indicate that these reptiles had no ability to float well in water’. We clearly do not say this and point multiple times to the high pneumaticity of ptersoaurs any say things including ‘it is not surprising that the pterosaur model floats on water’ and ‘We show that in general pterosaurs adopted a position that was high on the waterline’ which make it very clear they floated and floated well.

These five statements are varying degrees of problematic, but given that this paper has only less than 20 citations from peer-reviewed papers (and several of them are by me which I don’t think I’ve miss-cited) that points to a pretty high percentage of erroneous citations on this one piece of work. When several of them are clearly flat wrong, and even information in the abstract points to them being in error it suggests that it’s really not been taken on board. Hopefully this paper is simply unlucky in keeping getting such erroneous takes but it’s a shame that a paper that I’m really quite proud of seems to be repeatedly cited for things it doesn’t say or imply. It’s probably only a matter of time before it is used to contend that pterosaurs could not swim (something the paper also clearly does not say) and I’ve seen our paper referenced in this context in popular writing so it may yet go that way in the literature.

In short, read papers properly and check what you are saying. It’s important.

 

If you have read this far, I’ll trouble you for a few more words. You have read this blog post and may well have read many others of mine or enjoyed my book, seen TV shows I’ve consulted on or heard a podcast I did. If so, please take less than one minute to fill out this survey for me.

(Somewhat late) roundup of 2018

Lots of people are doing little end of the year reviews and with my general decrease in blogging in recent months this seemed a good motivation for me to do something similar if a bit later than everyone else.

It has been a fairly productive year for me research wise though there are lots more things that are nearing completion or are already out for review so hopefully the next couple of years will show a better return. Even the list below is inevitably a bit warped as some of these papers are effectively in press so will likely end up with a 2019 date on them, while others were out in 2017 but only now have a year appended.

First off are a few on the subject of trophic interactiosn between species. Most recently has been my paper on a Pteranodon with a shark tooth stuck in it, though this year also brough some theropod bite marks on juvenile dinosaurs. There was a rather broken peice of centrosaur frill that not nipped by something small itself, but more interestingly was a rather savaged juvenile diplodocid femur from Dinosaur National Monument. This one had bites very reminiscent of those made by derived tyrannosaurs at a time when they were not around suggesting simialr feeding mechanisms might have been present more extensively in big theropods and the paper also included some work on the issues of identifing ‘biters’ too.

My work on sexual selection and signaling also continued with two papers on this subject. First came one which is the first piece of work by my PhD student Andy Knapp looking at the evolution and changes in the horns and frills of various ceratopsians. This specifically targeted the idea that these things might have evolved as recognition signals but there was no evidence that these eveolved in response to sympatry (being in the same place so where you might want to be different to avoid confusion) and thus supporting the idea that they were more likely under sociosexual selection. Second in this area was work led by Devin O’Brien on the way things like ceratopsian frills grow which can be an indicator of sexual selection. This has been used in one form or another for years but this papers made things more rigorous in the use of reference traits for comparisons to sexually selected traits and marking out other things that also grow fast but are naturally selected.

Finally there’s a couple of papers that don’t really fit into either category. First there’s some work I was involved in looking at the exceptional preservation of dinosaur ‘dandruff’ and the implications that this brings about their biology. Second was a revision of the pterosaur genus Noripterus which has a complex taxonomic history and has suffered through most of the key material being lost. That turning up again allowed proper clarification over the definition of the taxon and a number of other genera that has been referred (os should have been to it).

So all in all a fairly productive time with a couple of my main research themes keeping pace while continuing to work on some other important areas. On the outreach front I continue to do lots of talks and school visits as well as podcasts and some consulting for various TV shows and the odd appearance. The Guardian cancelled their science blog network which ended the Lost Worlds, though it means I am doing more blogging here again as a result. Finally, an early 2019 addition was the creation of a Facebook page for my work and outreach which does a different job to both these pages and Twitter so do please follow me there too.

  • Hone, D.W.E., Witton, M. P., & Habib, M.B. 2018. Evidence for the Cretaceous shark Cretoxyrhina mantelli feeding on the pterosaur Pteranodon from the Niobrara Formation. Peer J.
  • Hone, D.W.E., Tanke, D.H., & Brown, C.M. 2018. Bite marks on the frill of a juvenile Centrosaurus from the Late Cretaceous Dinosaur Provincial Park Formation, Alberta, Canada. Peer J.
  • O’Brien, D.M., Allen, C.E., Van Kleeck, M.J., Hone, D.W.E., Knell, R.J., Knapp, A., Christiansen, S., & Emlen, D.J. 2018. On the evolution of extreme structures: static scaling and the function of sexually selected signals. Animal Behaviour.
  • McNamara, M.E., Zhang, F., Kearns, S.L., Orr, P.J., Toulouse, A., Foley, T., Hone, D.W.E., Rogers, C.S., Benton, M.J., Johnson, D., Xu, X., & Zhou, Z. 2018. Exceptionally preserved skin structure reveals the coevolution of skin, feathers and metabolism in feathered dinosaurs and early birds. Nature communications.
  • Knapp, A., Knell, R.J., Farke, A.A., Loewen, M.A., & Hone, D.W.E. 2018. Patterns of divergence in the morphology of ceratopsian dinosaurs: sympatry is not a driver of ornament evolution. Proceedings of the Royal Society, Series B,
  • Hone, D.W.E., & Chure, D.J. 2018. Difficulties in assigning trace makers from theropodan bite marks: an example from a young diplodocoid sauropod. Lethaia.
  • Hone, D.W.E., Jiang, S., & Xu, X. 2018. A taxonomic revision of Noripterus complicidens (Young, 1973) and Asian members of Dsungaripteridae. Geological Society of London, Special Volume, 149-157

Pteranodon vs Cretoxyrhina

Shark vs Pterosaur. By Mark Witton.

Over the last 10 years I have published quite a few papers on various feeding traces, shed teeth and stomach contents that help demonstrate and refine some understandings about who ate who in the Mesozoic. These are often very interesting but also frustratingly incomplete and it can be hard to identify one, let alone both, of the protagonists and in any case these are often isolated examples that may or may not represent wider trends. Still, at least sometimes there can be a good set of marks with repeated patterns and enough data to be quite confident about a relationship.

One such is that between the classic giant pelagic pterosaur Pteranodon and various sharks from the Cretaceous, most notably Squalicorax. This is no big surprise, these pterosaurs were spending a large amount of time out over the water and could probably dive and swim after prey, even if they didn’t likely sit for long on the surface when they did so. Even aside from the possibility of being caught, at least some pterosaurs must have died while out over the water or been stranded and ill or injured on the surface and that would inevitably attract large predators to come for a meal. Given the huge numbers of Pteranodon bones we have, it should not then be a surprise that there are a good number of them described with various bite marks that can be confidently attributed to large sharks. Pterosaurs were generally lightweight for their size but that doesn’t mean there was not some decent muscle on them and modern seabirds are not infrequently eaten by sharks providing a nice analogy too.

‘Complete’ Pteranodon at the LACM.

Such data though is limited to marks on bones and it’s always nice to have something more detailed than this. Although mentioned before in several previous papers, one outstanding Pteranodon specimen in LA has never been described or illustrated properly and so when I got my hands on it while visiting Mike Habib a few years ago, it was rather inevitable that something would happen, and the paper on that, with the healthy addition of Mark Witton as a collaborator, is now out.

The indivdual in question is mounted as a lovely complete (and sort of 3-D) pterosaur on display in the Los Angeles County Museum but it is a composite of somewhat indeterminate origin and it’s not entirely clear how many individuals were used to make it or how complete any of them were. What is clear though is that there is a short series of articulated cervical vertebrae and that these have the tooth of a decently sized shark with them. It’s trapped under a prezygopophysis so it’s hard to think it just drifted in there by chance onto a skeleton at the very bottom of the sea, and while the tooth doesn’t look like it penetrates the bone it is a reasonable interpretation that this is a shed tooth from a bite.

The tooth is diagnostic of the large pelagic shark Cretoxyrhina and we have a good enough idea of where in the mouth it sat which means we can get decent estimates of the sizes of each of the two animals here. The Pteranodon clocks in at around 5 m in wingspan with the shark being 2.5 m in length, but despite this apparent discrepancy, the shark would have been by far the heavier animal and in the water it would swim rings round the pterosaur. In short, while we don’t know quite what happened here (was it predation or scavenging) it looks like a decent sized shark took a chunk out of a pterosaur and lost a tooth in the process.

This is the first record of sucha trophic relationship between these two genera, though of course various unattributed bites that are already known might also have been made by Cretoxyrhina. However, despite the large numbers of Pteranodon specimens known, apparent bites on them turn up in only about 1% of cases. In some ways this may sound like a lot but there’s perhaps a 6% rate of carnivore-consumed interactions known for Rhamphorhynchus, so the open ocean (perhaps unsurprisingly) might have had fewer incidences of large predators getting to grips with large pterosaurs than near shore ones with much smaller animals.

All in all though, this adds a nice new point to the dataset on pterosaurs and their position in various food chains. We have a healthy record of them eating things, and being eaten, and each new bit of data like this helps us get a better and better handle on how pterosaurs fitted into ecosystems and how they might have lived, and died, in the Mesozoic.

 

The paper is fully OA and available here.

 

New Perspectives in Pterosaur Palaeobiology

So a new volume of papers in now online that I have edited and now there’s lots of pterosaur goodness to access. This is above titled volume produced by the Geological Society and is volume 455 in the Lyell Collection. The full list of papers and links is here but while most have been available online for some time, there is not this pretty published hardbacked version (cover art and photo by Mark Witton).

This volume is ultimately the product of the  2015 Flugsaurier meeting held in Portsmouth and features a number of papers that were presented there as well as others that have come in. There is a new taxon named (an anuroganthid!) and papers on taxonomy, systematics, anatomy, ecology, ontogeny and biomechanics. There are 17 papers and an introduction and as such I think it’s fair to say that this is a major collection and anyone with a serious interest in pterosaurs is going to need to read this.

Sadly the collection is not OA and these volumes can be expensive, but they are generally available at a reduced rate after a year or so. Unlike earlier editions the individual papers have been produced as high quality PDFs and distributed to authors, so if there’s a particular paper you are desperate for, I’m sure you can enquire. Personally I like dead tree versions of things, and this volume is printed on nice paper and has nice colour figures too which is clearly a bonus.

I should take a moment to thank Mark Witton and Dave Martill my coeditors in this venture and all the referees who took time to work on these papers. Also I’d like to thank the staff of the Geological Society who accepted our pitch and helped guide us through the work necessary to get this volume completed. I’m very pleased with the finla result and it’s nice to see citations already accruing for the papers within. The books are bing printed and shipped so for anyone who has ordered or was an author on a paper, expect these to arrive in the next few weeks.

Enjoy!

 

 

Flugsaurier 2018 Los Angeles

Well it’s been a while coming but the dates are finally fixed for next year’s pterosaur conference. Keep your diaries free for the 10th-14th of August next year.

As ususal there will be talks, posters, specimens and a fieldtrip (or possibly two) and we hope to be havikng a fairly major palaeoart presence as well. Details will be finalised ASAP but the basics are now all in hand.

Mike Habib is leading this one though his parent institutues of the University of Southern California and the Los Angeles County Museum. Luis Chiappe of the latter has been extremely helpful and the rest of the committee will comprise of Brent Breihaupt, Taissa Rodrigues, Lu Junchang, Liz Martin-Silverstone and myself. Volunteers for additional ssistance are also welcome.

Obviously this is still early days but a number of people have already committed and we are expecting a good turnout. Now that we are out of phase with ICVM, I am hoping that we will capture a bunch of people who are interested in pterosaurs but not been able to come in the past and not simply be solely those with a pterosaur research focus. If you have toyed with these animals or wanted to do more on them, or are a curator with a couple of bits in your collection this might be the conference for you.

Anyway, stay tuned, more will be coming soon and I’ll keep things posted here and e-mails will be going out to the ususal suspects as well as on the DML and Vert Pal lists and I’m sure we will get a Facebook group or simialr up and running soon. Hope to see you there.

In the meantime, almost all the papers from the Portsmouth meeting are now online and the formal book should be printe by the end of the year (or very early 2018), so now is the time to read up on your favourite flying mesozoic archosaurs.

Soft tissues and pterosaur taphonomy, but not as you might expect

In what now seems like a distant and past life, I briefly had a job in University College Dublin teaching in the biology department. Happily, this was on the floor above the earth sciences dept which had a healthy population of palaeontologists including some friends from my previous jobs in both Bristol and Germany. It meant that I had a good time chatting to colleagues on both sides of the ‘divide’ about various research aspects.

One day I was talking to Sue Beardmore (then doing her PhD) and her supervisor Paddy Orr about taphonomy. Through discussion with Paddy, Sue had developed a method of assessing the taphonomy of a vertebrate skeleton in aquatic settings, which could be used to compare environmental conditions among several localities, and infer differences and even changes through time. In theory, if we have the same or very similar species (that will essentially decay in the same way because of their similarities) preserved at two localities, it is possible that their final preserved state will still be different because they were subjected to different external processes. For example, they might have disarticulated to different degrees, suggesting differences in the relative time over which they had decayed before burial by sediments. If their completeness was different, it would suggest a greater number of, or more intense, (biostratinomic) processes. Perhaps one was exposed to stronger currents and less settled waters, which would move away any bits of the body that had separated during decay. In quiet water with few such processes, decay still occurs, resulting in the disarticulation of the skeleton without separated bits moving far from the main part of the carcass. Sue and Paddy have gone on to publish a series of papers exploring this idea, but I realized that it could also be turned around and used from an alternate perspective.

Differences in taphonomy between two related animals in the same environment should reflect differences in anatomy and in particular how well various body parts are secured to each other. In other words, the way in which various bits of the animals have decayed, disarticulated and / or lost allow us to infer something about the soft tissues, even though they are not preserved. This idea inevitably led me to pterosaurs and the huge numbers of Rhamphorhynchus and Pterodactylus specimens that have been recovered from the Solnhofen. They are pretty close relatives and certainly overlap strongly in time and space in these ancient lagoons but we also know that a profound shift in bony anatomy was going on between the two – is this also reflected in their soft tissue? Roping in Emma Lawlor who was then looking for a research project for her undergraduate dissertation, we then had a project to put together.

First off of course we needed to survey pretty much every specimen that we could (and as far as possible in person) leading to examining a whole lot of fossils and supported by photos where necessary. Essentially the animal is divided up into a bunch of segments (head, limbs, tail, body etc.) and are scored for articulation (attached to the right other bit of the body e.g. the wing to the shoulder, fingers to the wrist) and also completeness (so whether or not they are present on the specimen). A fossil could potentially be 100% complete but with 0% articulation, though the two factors are at least partly correlated since anything lost is also by definition disarticulated.

Going through the data there are some simple but fairly stark patterns that emerge. First off, a lot of the specimens are more or less complete and more or less articulated. That’s perhaps no big surprise – the Solnhofen waters are famously fairly anoxic and still, which is why we so often get lots of very well preserved specimens, even including fragile things like pterosaurs as well as soft tissues being retained. Still, it does highlight the general situation at play and that’s also importantly because pterosaurs were generally pretty pneumatic and less dense than many other vertebrates. That would imply that they could potentially float for a long time before sinking which would allow for lots of bits to come off and go missing. That this is generally fairly rare suggests that these effects were pretty limited. When we do see loss of articulation we also see loss of the elements, so decay when it did occur was likely mostly in the floating phase, and that things did not tend to fall apart much once the specimen had settled or we would see lower articulation with higher completeness. In short, there wasn’t much going on at the bottom, likely due to both low currents and limited bioturbation.

Generally, Pterodactylus specimens are less complete than Rhamphorhynchus which may point to them floating for longer (since they are more pneumatic) allowing things to be lost, but could also point to greater transport to sites before sinking and burial. There are also far fewer specimens of Pterodactylus available so this may be a result of the limited data exaggerating the differences a little.

Despite the long and presumably heavy tail of Rhamphorhynchus, this was preserved far more often than the much smaller one of Pterodactylus. This implies that in the former the tail was very strongly attached to the body and was held on with a strong set of muscles and / or ligaments and points to its greater use than in later shorter tailed pterosaurs. Where we see limb loss in Rhamphorhynchus this seems to coincide with the loss of the other limb from the same side – in short if you lose a left arm you also tend to lose a left leg. That points to the idea that the two are attached to each other quite firmly and tallies with the ankle attachment for the main wing membrane.

There’s some other issues at play in these patterns of course (and various other similarities and differences) which I won’t dwell on as that is what the paper is for, but this should give an idea of what we have done and what we can potentially infer with these methods. Sure, the information available is rather limited but it gives a framework for looking at certain anatomical areas in more detail, and it’s likely possible to combine this with other information to delve more deeply into our understanding of pterosaur soft tissues.

Beardmore, S.R., Lawlor, E., & Hone, D.W.E. 2017. The taphonomy of Solnhofen pterosaurs reveals soft-tissue anatomical differences between basal and derived forms. Naturwissenschaften.

 

A cornucopia of pterosaur papers

I’ve already covered here at some length my paper on the taxonomy of some of the Asian dsungaripterids as related to the rediscovery of some missing material of Noripterus. That paper is my entry to a volume that I have edited with Mark Witton and Dave Martill* and is the collected works that comes off the back of the 2015 Flugsaurier meeting in Portsmouth. This is being published by the Geological Society of London, an august institute to host this, and a nice hark back to the truly seminal 2003 volume they produced from the back of the Toulouse pterosaur meeting. It will be very hard to meet the standards of that collection (not least as it contained some absolutely fundamental papers on systematics and critical specimens) but I hope not to stand too much in that particular shadow.

Unlike many previous volumes this has the advantage of papers being published online as they come in and so we do not need to wait for the final paper to be sorted before the volume becomes available. That means that a number of papers are already available to read, even though not all of them are yet back from edits by authors and approval by the editorial team. We do hope to have the paper version out by the end of the year, but in the meantime there’s a pile of papers to enjoy.

There’s a diversity of subjects covered here with papers describing new specimens, revisions of existing taxa, new genera being named (or resurrected), a major new phylogenetic analysis, studies on muscles, jaws, and wings as well as various other bits and bobs. I won’t go through them one by one, you can see the list here (and it will continue to update as papers come in). The volume is, sadly, not OA but the production of PDFs means that authors have copies that can be readily disseminated so as with many papers, an e-mail should secure you a copy (and people like to know their work is being read). There should be something in here for everyone (provided of course you like pterosaurs) but here’s a select group of personal highlights so far (and some other important and interesting papers are coming).

First off would be Mark Witton’s excellent review of pterosaurs in food chains – both things they ate and that ate them. This deals exclusively with direct evidence of diet (stomach contents and the like) of which there is a fair bit, rather than so much work which is understandably often built on inferences about these relationships. It’s an excellent foundation for this area which is growing quite rapidly.

Next would be Chris Bennett’s paper with Paul Penkalski on a bizarre Pteranodon that has a striped skull. This isn’t (sadly) colour patterning or soft tissues but remarkably seems to be a pattern of the bone itself. It’s really quite strange and shows that even pterosaurs we know well can pop up with some big surprises.

Finally there’s Colin Palmer’s paper on the properties of pterosaur wing membranes. Although not the first to tackle this subject, since the last major review and set of hypotheses on their performance, we have learned a lot about the structure of the soft tissues, the layers that go into it, and the size and shape and extent of the main wing as well as the orientations in which it likely functions. That makes a synthesis like this very useful as both a review of where we are and what we might expect as well as giving us ideas to test.

I’ll leave that here for now and let readers explore the volume as it firms up. It only remains for me to thank my co-editors and the various referees as well as of course the authors themselves and the people at the Geological Society for their help with producing this volume and  look forwards to seeing the final printed version.

 

 

  • For the record as this kind of thing has caused consternation among some before, I did not have anything to do as editor with my own authored paper. It was handled entirely independently by the other editors and I had no access or input to the process (and nor did they to their own papers). In a small field like pterosaur research it’s hard if not impossible to find referees and editors who are truly independent, and it’s a bit odd to exclude people who have the knowledge to edit a volume from contributing to it, so this is the best solution. This really is common in lots of specialist volumes, but it’s worth noting that it was done as transparently and ethically as possible.

 

Noripterus returns – sorting out some pterosaur taxonomy

New reconstruction of Noripterus by Rebecca Gelerenter. This is a composite based on all the material we have from various specimens (known material is in white).

New reconstruction of Noripterus by Rebecca Gelerenter. This is a composite based on all the material we have from various specimens (known material is in white).

Immediately after the Munich pterosaur meeting ended in 2007, I moved to Beijing to take up a postdoctoral position at the IVPP. Perhaps the first bit of mail I has there was from the now late Wann Langston thanking me for setting up the Munich Flugsaurier (which he had attended) and sending me a photocopy of his notes and some old photographs he’d taken on a trip to China back in the 80s. This was of a superbly preserved pterosaur hindlimb, and one he wanted to know more about but which had since not been seen by any researcher he knew, or been in the literature.

This was a specimen of Noripterus, a small dsungaripterid from China found by, and then named by, C.C. Young back in 1973. The original description of this was both a bit sparsely described, and in Chinese which is a shame as Young mentions a number of specimens, and illustrates or measures only part of some of them. I asked around the curators at the IVPP but no one knew the location of the material and it was suggested to have been borrowed and not returned.

Fast forward a couple of years and while Paul Barrett was visiting the IVPP he had been directed by a colleague to a little used set of cabinets in the collection, where apparently some mislaid dinosaur material was residing. I happened to be looking over a specimen in the collections at the time so inevitably was keen to see what might turn up. On opening the case, Paul found his specimens, but one thing I spotted was immediately recognisable from Wann’s photos – the lost Noripterus foot. Accompanying it was quite a lot of other pterosaur specimens with similar specimen numbers – Noripterus was back.

Since then I’ve been working on and off on a number of projects on these specimens (hampered by my no longer being in China) and the first is finally out as part of the volume from the back of the 2015 Flugsaurier meeting in Portsmouth. A more full description is in the work but this is the first and important step because the taxonomy of the Asian dsungaripterids has been an issue that’s been problematic for quite a while, and much of it hinges on Noripterus.

Things have been difficult to resolve because as noted, the original description doesn’t give that much information on the material (and less if you don’t speak Chinese – I am indebted to my collaborators here as you may imagine). If you want to sort out how various other species and genera relate to it (or not) you really need to know what it actually is anatomically and taxonomically, and so having the specimens available means we can make some significant updates to Young’s identification and how other more recent discoveries might relate to it.

First off the bad news – what was originally designated as the holotype is mostly still missing. Only a fragment of the jaws remain and they are not in great condition. Still, they are diagnostic which helps us to define Noripterus better. On the good news side of things, there is a lot of nice associated material as Young collected multiple specimens from just a few sites and despite the lack of overlap in some areas, there’s some good reasons to think they are all the same thing. Noripterus is known from several superbly preserved specimens including a near complete set of limbs and girdles preserved in 3D. There will be more on this in the future, but obviously it’s very useful material to have.

A superb set of limbs from one specimen of Noripterus

A superb set of limbs from one specimen of Noripterus

Working out quite which specimen was which however actually took quite some time and detective work. The field numbers on the bones and the specimen numbers on the boxes they were in, did not always line up with the identities given in Young’s paper (either illustrations or the few measurements).  Eventually though we got this sorted out and so one part of the paper gives some new specimen numbers and sorts out the various specimens into their (hopefully) correct sets.

The main issue though is the taxonomy itself of these animals. Noripterus was only the second dsungaripterid identified (you may not be shocked to learn Dsungaripterus was the first) and so it might not be a surprise that it’s considered a valid taxon. It is rather smaller than it’s more famous relative, and has straight rather than curved jaws, as well as rather more narrow teeth. That’s the easy bit.

Then we have ‘Phobetor’ from Mongolia, named from some very fragmentary material that has never been described in detail. More recently there’s more Mongolian stuff from 2009 called the ‘Tatal pterosaur’ that was used to link together that material, ‘Phobetor’ and Noripterus all under the latter name. On top of that we have the Chinese genus Longchognathosaurus known from little more than a few bits. Clearly lining these up and working out if there were one, two or three genera was going to prove difficult while 2 of these 4 sets of specimens were fragmentary and most had never been described or illustrated properly. In this context, getting to see Noripterus was clearly very useful in terms of making some meaningful comparisons of key characters.

So, what did we find? Well, actually the Tatal material and the original ‘Phobetor’ are very similar based on the limited descriptions of each suggesting they are the same taxon. However, they have some consistent differences with the Noripterus material which suggests they represent a valid and separate genus and should not be synonymised with it. That also means that ‘Phobetor’ is still lacking a name (it’s preoccupied by a fish). Finally, Longchognathosaurus has at least a couple of the supposedly diagnostic characters present in the holotype of Noripterus and while it’s not necessarily the same thing, it is hard to justify it being unique at this point.

Clearly all of this is provisional, and lacking a good skull for Noripterus (or at least the rest of the holotype) would really help firm all of this up, not least when the Tatal specimens include a good skull and Longchognathosaurus is based mostly from cranial material. In fact given how much good Noripterus material there is, it is an oddity that there’s so little of the head, but hopefully more will turn up. In the meantime, this should help move things forwards and provide a better basis for sorting out these taxa and some curiosities about their relationships to other pterosaurs (in particular Germanodactylus which may or may not be an early dsungaripterid). Now we just need some more detailed descriptions of all the other Asian dsungaripterids (and yes, more on Noripterus too) but this is a start.

 

TLDR: We have a good amount of Noripterus back. ‘Phobetor’ is probably separate and valid and the same thing as the ‘Tatal pterosaur’ material. Longchognathosaurus is probably not valid.

 

Flugsaurier 2015 Volume of Papers announced

I’m putting this up here as I do still get a fair number of visitors and obviously this site is still very pterosaur centric. Pterosaur enthusiasts will know there have been a series of volumes of pterosaur reseach stemming from the various conferences in the last decade or so. First and foremost among them has been the Geological Society’s special volume from 2003 that came from the meeting in France. Happily the same venue have agreed to publish the next in the series which is based on the the recent conference in Portsmouth. Potential authors should read on!


 

Dear Authors,

We have now had confirmation that the Geological Society will be publishing a special volume of papers centred around the 2015 Flugsaurier conference that was recently held in Portsmouth, UK. This volume will be edited by Dave Hone, David Martill and Mark Witton.

The Society have set a deadline of the 31st of January 2016 (a Sunday) for the first submission of manuscripts. This is relatively short notice, but includes the Christmas and New Year periods when traditionally teaching commitments are relatively low. At nearly 3 months away, hopefully this not too onerous a deadline. Formatting and submission instructions can be found here: www.geolsoc.org.uk/sp_authorinfo

Manuscripts will be taken through a full editorial process and subjected to peer review. Manuscripts may be rejected or subjected to multiple rounds of review if their content is not endorsed by referees. Unlike the very successful 2003 Geological Society pterosaur volume, accepted manuscripts will be published online immediately after review and corrections. Volume contents will therefore not be held up by any delays surrounding single manuscripts. A hard copy volume will be printed once all manuscripts are accepted, the deadline for which is 2017.

The volume has capacity for a large number of manuscripts and we encourage submissions. If space does become an issue, we will prioritise content related to material presented at Flugsaurier 2015, and authors who have already announced an intention to submit to the collection.

Please do contact us if you have any questions or queries. We look forwards to reading you research.

Yours,

Dave, David and Mark

 

 

Pterosaur wingtips – not on the straight and narrow

Take a look at almost any illustration of a pterosaur, be it in a research piece or a life reconstruction and the wing finger is generally depicted as being some kind of straight spar. Each of the four wing finger bones is a dead straight element and the leading edge is therefore basically just a line drawn with a ruler). However, take a look at the actual specimens of pterosaurs and it’s actually quite clear that for lots of them, the last (distal) element is often curved, if only a little, but sometimes quite a lot.

This is really obvious in something like Pteranodon for example (and indeed it’s been noted before that this genus has curved distal phalanges) and yet illustrations of this animal, even in the technical literature, will give it a straight distal phalanx. I’d noted for a while that actually there were quite a few pterosaurs with curved phalanges in particular having looked at Bellubrunnus and its bizarre forward swept wingtips. I’d realised that even the posterior curve might actually have some major flight implications – the shape and position of the very distal part of the wing can have a big impact on vortex shedding and other issues even in static glides and anything like a twist or elevation to the tip can make a huge difference to how it performs.

Knowing this would be an issue and working out what it would be and why are two very different areas and I know enough mechanics for the first and not enough to even begin to think about the second. Enter, somewhat inevitably, Mike Habib and he started looking at this issue and working towards what such a curve would mean both in Bellubrunnus but also those pterosaurs with posterior curves on the distal phalanges. We still needed a good dataset and some actual numbers though and so while I trawled the literature and my photographic archives for examples, any I found I passed onto Matt Van Rooijen who had volunteered to produce both the figures for the paper but also do the detailed digital measuring of the curvature of the phalanges.

The resultant paper is rather light on in depth analysis and numbers because there are potentially some severe issues of taphonomy that can distort the apparent curvature of these bones (in particular reducing a curved bone to look straight) but given the strong consistency of at least some results, there do appear to be some major and genuine signals in the data. There’s some fair consistency within and between clades therefore (and to a degree within and between species of a single genus) so despite the taphonomic issue, it’s perhaps not too bad (though still very hard to estimate or account for).

A number of specimens of multiple genera show that scaphognathines and tapejarids have relatively strong curvature to the distal phalanges and so to do various pteranodontids. In other words, two groups often considered to be highly terrestrial, and another than is highly pelagic both seem to go more for this curvature and others show lesser or no curvature. This might seem rather odd with the two extremes of flying environment / style coming together in morphology but it actually makes a fair bit of sense.

Curvature in the pteranodontids would potentially correspond to an expanded wingtip which aligns with existing hypotheses of the forward swept wing position of these animals in flight. A curved wingtip can also increase the chord of the wing which would be good for terrestrial-based fliers, and also might help protect the wingtip from damage from impact which could be important for animals flying in cluttered environments.

An additional issue comes in here of compliance, a compliant phalanx could potentially also help reduce injuries from impact with things like twigs or even the ground when taking off. Bat phalanges are highly compliant (i.e. bendy) under loads but eyeballing bat fossils at least, there’s no obvious difference between the bones of the phalanges and other elements of the skeleton that are less compliant, so perhaps at least some pterosaur phalanges were highly compliant. In that case under loading in flight they could be considerably more curved, and those of Bellubrunnus might actually be straight in flight!

Overall then this paper has a bit of something for everyone (hopefully). There is likely to be some kind of taxonomic and systematic signal in the presence of curved wingtips though it would have to be treated with caution as a potential character, but that’s also true of lots of other things too, it should not be overlooked. Second, there really does seem to be an ecological signal there which helps potentially restore the ecological habits and habitats of various taxa. There is very much some aerodynamic ideas in here which can be explore further in terms of wingtip shape, and the implications for thing like chord, stall speeds and how this might relate to wing position in flight. Out hypothesis about compliant bone can potentially be tested with histological sampling and finally this should provide a bit more information for those of the artistic persuasion who like drawing pterosaurs. Enjoy!

Hone, D.W.E., van Rooijen, M.K., & Habib, M.B. 2015. The wingtips of pterosaurs: anatomy, aeronautical function and ecological implications. Palaeogeography, Palaeoclimatology, Palaeoecology, 440: 431-439.

Flugsaurier 2015: Portsmouth, UK

Way back in 2001 the first real symposium dedicated solely to pterosaurs (rather than a subset of another conference) was convened in Toulouse thanks largely to the organisation of Eric Buffetaut. By all accounts it was a success and spawned the well known and much cited 2003 Evolution and Palaeobiology of Pterosaurs special volume. The event however was something of a one-off, and I don’t think there was any great plans to have another later conference.

At the end of my time in Germany however, I wanted to arrange a conference and with the museum home to some legendary pterosaur specimens and the retiring Peter Wellnhofer, this ultimately led to Flugsaurier 2007 in Munich. Both a celebration of all things pterosaurian and a tribute to Peter’s career, this was attended by nearly 50 people with delegates from North and South America, Asia, Australia and Europe, and later spawned the 2008 Festschrift for Peter. At the meeting it was agreed that this would be an excellent series to continue and so Flugsaurier 2010 in Beijing was immediately announced, and then this was followed by a shift to South America and Rio 2013 collectively covering three of the great centres for pterosaur finds and research. Each meeting has seen a swathe of researchers descend on the host institute and the unveiling of some up to the minute research and important new finds.

Now though, Flugsaurier returns to Europe and will be in Portsmouth in 2015 from August 25th-30th. Dave Martill is the main organiser of this one at his parent university, ably assisted (well, we think so) by a small army of associates. As has become usual for Flugsaurier, the conference will consist of talks and posters about pterosaurs, workshops and round-table discussions, specimen viewings and fieldtrips. It is NOT limited to academics, and we have a good record of artists, non-pterosaur specialists, curators, and the general public attending as delegates as well as early-career researchers like MSc and PhD students presenting their work. As a generally small meeting, it is rather informal and there’s lots of break-outs and discussions between presentations and through the breaks and evenings and much to talk over.

All the major details are on the website for the event here, and the first circular is already out and online here. Do please share these links with the wider academic and social community (we have tried and failed to get e-mails to the DML and VertPal list so if someone could send out the links, that would be wonderful, thanks), there is a group on Facebook, an @Flugsaurier2015 twitter feed and also we’re using the hashtag #flugsaurier2015 to keep people up to date. More information will follow soon, but the basics are up and online and registration will open shortly.

Some of the best interactions and exchanges we have had at previous meetings have come from those who normally only dabble in pterosaurs and are bringing external ideas and methods into the community so while obviously there is a *lot* of winged reptile stuff going round, it’s not just a meeting of the usual pterosaur suspects. Indeed in this case we really hope for a bit more of that at this one as thanks to some cunning timing, the meeting will run just before SVPCA in the neighbouring city of Southampton.

Yes, you can attend two palaeontological conferences in succession! SVPCA, for those that have never been, is a meeting for vertebrate palaeontology and comparative anatomy. Although very UK centric, SVPCA always attracts a number of European delegates and even those from further afield (Matt Wedel and Don Henderson regularly attend for example) but is also a small meeting (generally around 130 people) and as such is an informal and fun community. There’s no parallel sessions and a relaxed and fun atmosphere (last year we had a presentation done in song with guitar backing!) and it also includes a day for preparators and conservators on top of covering everything from fish to hominids over the run time. SVPCA is also a special haven for palaeoart people (Bob Nicholls, Luis Rey, Mark Witton and John Conway are always there, and those with big outreach profiles like Darren Naish and Dougal Dixon also always attend). In short, those who might be considering a major journey from across the ocean for just a few days of pterosaurs and think it a bit much money and commitment, well the opportunity to combine it with SVPCA hopefully makes it a still greater proposition.

The fieldtrips will also be run in such a way as to maximise this too. A pre-conference excursion to the Isle of Wight on August 25th will effectively start Flugsaurier, and then a post-conference weekend field trip to the Jurassic Coast World Heritage Site on August 29th and 30th will be run jointly with SVPCA as a prelude to that meeting.

Hopefully then there’s some excellent scope for friends, colleagues, researchers and interested people from all over the world to take the opportunity to come to the UK and both meetings. Pterosaurs may not be your first or only love, but the integration with SVPCA makes a superb opportunity to combine the two and see two whole vertebrate meetings. Both are relatively cheap, and with an international community heading over for Flugsaurier as well as a European crowd for SVPCA, it will hopefully be both intimate and wide-ranging.

As a quick aside, note that the plan was always for Flugsaurier to be on a cycle of every three years, but we quickly realised that this cycle specifically ran with the huge ICVM and was sucking up some of our potential delegates who naturally did not want to make two big international trips per year on top of the usual SVPCA / SVP trips. So this one comes just two years after Rio, but we should return to the previous cycle after this and hopefully someone will be volunteering to host Flugsaurier 2018.

I do hope to see an excellent turn out for both (apparently we’re running at nearly two dozen registered for Flugsaurier already in just the first few days of putting out the first circular) and that will grow quickly I’m sure. Roll on 2015!


@Dave_Hone on Twitter

Enter your email address to follow this blog and receive notifications of new posts by email.

Join 501 other followers