Posts Tagged 'Pterosaurs'

New data on pterosaurian soft tissues

Published 10/06/2025 Uncategorized Closed
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Pterosaur fossils are rather paradoxical in that they are generally very rare and fragmentary outside of the few places of exceptional preservation, where they become not only common, but contain the kinds of data most palaeontologists dream of seeing. Not only do we have a lot of very complete and well-preserved specimens, but a great many with various bits of soft tissues too. In addition to the obvious wings, we have beaks, claw sheathes, soft tissue head crests of various forms, throat pouches, tail vanes, scales on the feet, webbing between the toes and, of course, the pycnofibers – we even have some traces of muscle tissues in some. I suspect if we added it all up, we’ve actually got generally more and better soft tissue data for pterosaurs than even the feathered dinosaurs, and from a fraction of the number of specimens too.

Still, there are some bits that are less well known, and various specimens out there that have never been described well or have only recently come to light and so have not been looked at in any detail. As you can imagine, I have a new paper published today looking at some of these exact details, though as so often happens, it’s sort of an offshoot of something else.

As part of my ongoing work tracking down various undescribed Pterodactylus and Rhamphorhynchus specimens, I’ve come across various large bits from Solnhofen beds sitting in museum collections. The really huge wings that I’ve seen, I actually wrote up with my then PhD student Ross Elgin a few years back, but we knew there were more out there, including isolated legs and feet. When I started working with René and Bruce Lauer on the collection from their Foundation, I soon spotted a really nice large leg and foot and thought this would be a good starting point for a paper on these isolated limbs. What I did know until they showed me, was that completely invisible under natural light, the specimen had some exceptional soft tissue preservation under UV, and it was not the only isolated bit like this in their collection. So began a slightly odd pairing of subjects in a paper – large isolated pterodactyloid feet and the soft tissues associated with them. There’s obviously lots more in the paper on these two specimens as well as some others from other collections, but I really want to focus here on the soft tissue material.

The first thing to look at is the webbing between the toes. This has been seen before, including deep in the crux of the metatarsals, but it is arguably clearer and deeper here than seen before and with very clear striations that presumably mark some kind of thickening or stiffening fibers to support it. This is important as it shows that the metatarsals were not bound together at the base of the foot but could themselves spread out if the webbing goes that deep between them.

Of greater interest are the scales on the soles of the feet. These have also been seen plenty of times before, but again are incredibly well-preserved here and certainly the best I’ve seen in person and arguably the best out there. These are incredibly similar to those seen in other pterosaurs which on the one hand is hardly a surprise, but when that includes things like Rhamphorhynchus and then animals as far apart in time and phylogeny as azhdarchids, then it becomes clear just how consistent these apparently were. It looks like pterosaurs sorted out their foot scales out early and then stuck to that pretty much forever.

What’s more surprising is that one of the specimens that represents a wing and a leg, also preserves scales on the hand, and these are, to our knowledge, the first recorded for pterosaurs. Now that should immediately strike you as odd – pterosaurs were quadrupeds and given their build, took a lot of weight on their hands. So, wouldn’t these have scales that were at least as large and tough as those of the feet? Well, apparently not given that we do have a bunch of fossils with scales on the feet but not the hands. Clearly some were present or we wouldn’t see them here, but their clear rarity compared to the feet is a real oddity and difficult to immediately explain, not least when the scales seen here are almost identical to those seen on the feet. We might have just been unlucky and missed them before or they were accidentally lost in preparation, but it does appear to be a pattern.  

All in all, there’s some nice information here and some really neat nuggets of pterosaur anatomy and taxonomy have come out of this, so it’s certainly a paper worth taking a look at if pterosaurs are your thing. There’s more to come too as I have another pterosaur soft tissue paper due out soon so stay tuned.

The paper is Open Access and available here: Hone, D.W.E., Lauer, R., & Lauer, B. 2025. Soft tissue anatomy of pterosaur hands and feet – new information from Solnhofen region pterodactyloid specimens. Lethaia.

Check out the Lauer Foundation website too.

A second specimen of Luchibang?

Published 07/08/2020 Pterosaurs 2 Comments
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I was going though a bunch of files this week hunting down some photos of Chinese pterosaurs and came across this one. I took it in a small private museum in Liaoning ten years ago and so didn’t record any details at the time since the material was never likely to be accessible for study and I was only there for an hour or so. There’s also no scale and of course the lighting is less than ideal. My memory of it is sketchy at best, but I remember it being quite a large specimen, though if it has stuck in my mind any further it would have been obvious then (and indeed more recently) what it looked like – it could be a second specimen of Luchibang.

A second specimen of Luchibang?

One thing that was very difficult with naming that taxon was establishing that it was genuine given its unusual mixture of features and proportions. Despite a very extensive section in the supplementary information of the paper on nature of the specimen and extra preparation work to establish that is is genuine, I’ve still seen comments online (including from people who should know better) claiming it might be a composite. I have though also heard of other specimens in China that are long-legged istiodactylids and apparently I’d already seen one but forgotten.

This is clearly an istiodactylid based on the skull, with the classic rounded jaw tip and teeth limited to only the front of the mouth. Like Luchibang and indeed a number of Liaoning istiodactylids, the mandible has rotated and is not in lateral view like the rest of the skull (though here the skull is rather crushed). The neck vertebrae are similarly ornithocheiroid-like and also preserved in dorsal view. The wings and legs though are not like ornithocheiroids, with a wing-finger with distinctly azhdarchoid-like proportions and long hindlimbs with large feet. This would generally be an odd combination, but taking some quick measurements on the photo shows that the broad proportions of the jaw, coracoid, humerus, ulna, wing metacarpal, wing phalanges, femur, tibia and metatarsal are all very similar to those of Luchibang. At the bare minimum that makes this extremely intriguing and without looking further into it, does make this a potential second specimen.

That said, there needs to be caution here. Looking as closely as possible at this less than perfect photo, throws up some oddities. The toes are a rather odd colour compared to the rest of the skeleton (though they look like they might simply not have had lacquer put on them), the humeri look weirdly wide (though could be crushed), and the wrist elements appear to be missing. There’s some kind of odd effect around many of the bones which could be clean up work and some filler, but could also be where bones have been moved around to make things look better, or of course rather worse, have been added in from another specimen. Even so, as with Luchibang, there is very considerable overlap across numerous elements. The mandible overlaps one of the wings, the cervicals overlap with the scapulocoracoid, the proximal wings and femora overlaps with the mass of bones of the torso and other wing and leg parts are in close association with each other.

So while I’d preach caution about this specimen without much better photos (and of course far better still, seeing it in person), it is a credible candidate for a second long-legged istiodactylid. Despite the fact that it looks like it has had work done on it, it would be rather odd indeed that someone had created a composite where they had managed to find an istiodactylid skull with a first wing phalanx of the correct length underneath it and of the right colour and preservation type to match with an unrelated azhdarchid body of the right size and proportions, that happens to have an ornithocheird-like posterior cervicals on it, and where all the different elements are a match in size for a second, unrelated specimen. In short, while some details are a little questionable, it looks like the majority of the elements as presented are all from a single specimen and that’s an azhdarchoid-like winged and legged istiodactylid, and right now that means Luchibang.

More and better presented specimens with proper descriptions are really needed here, but I think on balance this provides reasonable mutual support of both specimens being genuine. The faked Chinese fossils I’ve seen have numerous obvious anatomical issues or the composite parts are of very different preservational quality and type. Even poorly faked and restored specimens are often sold for very large sums and the goal is to produce something extremely aesthetically pleasing, not scientifically plausible, so there’s little motivation to make exceptional and high-quality fakes, especially from specimens like this one where the skull is mashed up. As such, then as reported, there do appear to be more of these istiodactylids out there with the potential to explain a lot more about their unique proportions and ecology and this is hopefully only an indication of more to come from Chinese collections.

 

Sexual selection in dinosaurs, the story so far…

Published 11/05/2020 Dinosaurs , Pterosaurs Closed
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I have a major new paper coming tomorrow on sexual selection in dinosaurs. This is an area in which I have been extremely heavily involved in the last decade and have published numerous papers on this subject with various colleagues, writing about the underlying theory of sexual selection and how it might appear in the fossil record, providing evidence for it and actively testing hypotheses. This has also led into my working on related issues of ontogeny and social behaviour in dinosaurs which feed back into these areas to try and deal with certain aspects that came up as a result of these analyses.

Suffice to say I’m not going to go back over the whole history of my work in the field, or that of plenty of other researchers which is both relevant and important. But a little bit of context is important with respect to the coming paper because it’s something that I’ve had in my mind to do for about as long as I’ve been working on this subject but I didn’t think I’d be able to do because the dataset didn’t exist.

All of the work I have done really tried to get into answer the questions of which features of which dinosaurs may have been operating under sexual selection and can we tell. (More properly, I should say socio-sexual selection since teasing out social dominance signals from sexually selected signals is probably impossible though mostly the two are more or less synonymous in various ways so it’s not a major issue conceptually). The short answer is that really quite a lot of features probably are under some form of sexual selection. We can see this by the fact that we can rule out functional explanations for things like ceratopsian crests as being anchors for muscles attachments, radiators, or for defence because they are highly variable and / or fundamentally don’t work (Elgin et al., 2008; Hone et al., 2012). They are costly traits to grow and lug around (be they stegosaur plates or hadrosaur crests) and so clearly have a fitness cost, ruling out species recognition as a signal (Knell et al., 2012; Hone & Naish, 2013). Similarly, there is no clear pattern of differentiation among sympatric species as would be critical for a recognition trait (Knapp et al. 2018). They are highly variable both within and between species, another hallmark of sexually selected traits (Hone & Naish, 2013; O’Brien et al., 2018) and finally they grow rapidly as animals reach sexual maturity which is absolutely characteristic of sexual selection (Hone et al., 2016; O’Brien et al., 2018).

The one issue that has remained elusive in all of this is the vexed issue of dimorphism. This has proven very hard to detect for a variety of reasons, but most notably the generally small sample sizes we have for dinosaurs and the tendency for males and females to overlap in size and morphology over much of their lifespan (Hone & Mallon, 2017). To top it off, mutual sexual selection can reduce or even eliminate dimorphism making it harder still to detect and meaning even an apparent absence of it, does not mean sexual selection is not in operation (Hone et al., 2012).

It would be nice to be able to explore the issue of dimorphism in particular in more detail with an extant analogue. Plenty of comparisons have been made to various living taxa in terms of dimorphism (be it body size or major features like a crest or sail) but they run into various issues. Mammals are nice and big and often have things like horns that differ between males and females (either in shape or presence / absence), but they’re phylogenetically very distinct and have the problem of growing quickly to adult size and staying there. Lizards offer something interesting with some dimorphic species with various signal structures (like some chameleons) but then while they are reptiles, most are small and the biggest varanids have no sexually selected structures. Birds are obviously literally dinosaurs but have a mammalian-like growth and are not very big. While there’s plenty of size dimorphism in them, there are few that have obviously dimorphic traits that would show up in the skeleton (like horns).

That leaves the crocodylians, which are off to a good start. Some are very large and take a long time to grown to adult size, all are egg layers, they are sexually mature long before full size meaning they would likely express sexually selected traits while still quite small (like dinosaurs and unlike birds or mammals), and a number are also sexually dimorphic in body size. The only thing missing is some kind of sexually selected bony feature, or at least one with a clear osteological correlate.

And so to the gharials, the wonderfully weird crocodylians of the Indian subcontinent which tick every single one of these boxes right down to the growth on the snout of males, the ghara, that is absent in the females. This has long been obviously the one taxon that ticks pretty much every possible box and would provide an excellent living model to analyse and see how easy (or not) dimorphism is to detect when you have a known dataset to work from. The obvious limit to this plan is that these animals are extremely rare and most museums have few, if any, specimens. The one species that was pretty much perfect for my plans immediately fell out of contention because I couldn’t see how I could get a dataset together that would be sufficient for analysis, so the idea was shelved. Until recently…

Obviously, to be continued.

 

Papers on sexual selection, dimoprhism, socio-sexual signaling, social behaviours and related subjects in fossil reptiles:

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.

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., & Mallon, J.C. 2017. Protracted growth impedes the detection of sexual dimorphism in non-avian dinosaurs. Palaeontology, 60: 535-545.

Hone, D.W.E., Wood, D., & Knell, R.J. 2016. Positive allometry for exaggerated structures in the ceratopsian dinosaur Protoceratops andrewsi supports socio-sexual signaling. Palaeontologia Electronica, 19.1.5A.

Hone, D.W.E. & Faulkes, C.J. 2014. A proposed framework for establishing and evaluating hypotheses about the behaviour of extinct organisms. Journal of Zoology, 292: 260-267.

Hone, D.W.E., & Naish, D. 2013. The ‘species recognition hypothesis’ does not explain the presence and evolution of exaggerated structures in non-avialan dinosaurs. Journal of Zoology, 290: 172-180.

Knell, R., Naish, D., Tompkins, J.L. & Hone, D.W.E. 2013. Is sexual selection defined by dimorphism alone? A reply to Padian & Horner. Trends in Ecology & Evolution, 28: 250-251.

Knell, R., Naish, D., Tompkins, J.L. & Hone, D.W.E. 2013. Sexual selection in prehistoric animals: detection and implications. Trends in Ecology and Evolution, 28: 38-47.

Hone, D.W.E., Naish, D. & Cuthill, I.C. 2012. Does mutual sexual selection explain the evolution of head crests in pterosaurs and dinosaurs? Lethaia, 45: 139-156.

Taylor, M.T., Hone, D.W.E., Wedel, M.J. & Naish, D. 2011. The long necks of sauropods did not evolve primarily through sexual selection. Journal of Zoology, 285: 150-161.

Elgin, R.A., Grau, C., Palmer, C., Hone, D.W.E., Greenwell, D. & Benton, M.J. 2008. Aerodynamic characters of the cranial crest in Pteranodon. Zitteliana B, 28: 169-176.

 

 

Many more Cryodrakon images

Published 28/10/2019 Palaeoart , Pterosaurs 1 Comment
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Scavening on a dead Cryodrakon by Mark Witton

Chatting to Mark Witton the other day it transpired that artwork of Cryodrakon has already existed for some year. Large azhdarchids would have been a decent meal for small scavengers and we know of at least two incidences of dromaeosaurs eating them, one of which being the holotype of Cryodrakon (the other was Velociraptor I described with a pterosaur bone in it). The above piece was done in reference to this but Mark told me his point was to specifically reference the Canadian specimen which only now has a name.

I’m sure there’s other artworks out there that similarly were based on this northern ‘Quetzalcoatlus’ and would now refer to Cryodrakon, but almost inevitably once the paper came out there was a rush on to produce new images that rapidly appeared online alongside the ‘official’ artwork of David Maas. Here are a few of those.

Cryodrakon attacks a dromaeosaur by Gabriel Uguerto

First off is that by Gabriel Uguerto and this one is a bit of a cheat perhaps because he drew it for me as a commission but I’m delighted to have the original and it’s nice to see an azhdarchid giving something back to the theropods and not just being eaten by them or only following what is now a meme and eating baby sauropods.

Cryodrakon skeletal (full sized) by Dean Schnabel

There are already skeletal outlines appearing for Cryodrakon too. Dean Schnabel (who goes under the pseudonym of Sassy Palaeo Nerd on Deviant Art and Twitter) has produced two. One of all the known material scaled to the incomplete giant cervical (above) and a second that is just the holotype material at the correct size for that specimen (below).

Cryodrakon skeletal (holotype only) by Dean Schnabel

Finally, Joschua Knüppe put out this black one on an especially snowy background. While on the subject of snow, it’s popping up a lot I artworks already. The name Cryodrakon was intended to invoke Alberta as it is now rather than when the animal was alive when it was semi-tropical. That doesn’t though mean that snow is wrong (indeed David Maas sneaked a bit into one of his images) as even the warmest places will get snowfall on occasion and azhdarchids generally could fly long distance and the newly forming Rocky Mountains were not far away. I’m sure on occasion Cryodrakon ended up striding through snow and flying over white landscapes even if it wasn’t the norm.

Cryodrakon in the snow by Joschua Knüppe

These are not the only ones out there, a quick google will reveal a wealth of alternate takes on Instagram, Deviant Art and elsewhere (alongside a load of older rebadged art that various media organisations stumbled to produce and plenty of versions of David’s work, often inappropriately rebadged with someone else’s watermark). More I’m sure are coming but it’s nice to see your own scientific work reach out into people’s imaginations and artistic efforts.

 

Coda: I spoke to all the artists about linking to their work before putting them up here.

The problem with floating pterosaurs

Published 28/02/2019 Pterosaurs 4 Comments
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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.

 

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Pteranodon vs Cretoxyrhina

Published 14/12/2018 Pterosaurs 1 Comment
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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.

 

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

Published 24/07/2017 Pterosaurs Closed
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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.

 

Noripterus returns – sorting out some pterosaur taxonomy

Published 23/02/2017 Pterosaurs 2 Comments
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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.

 

Archosaur Musings 2015 Roundup

Published 02/01/2016 Uncategorized 1 Comment
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For the first time I’m breaking away from the previous annual awards and I’m writing something that is more of a general roundup of the year. I already had found I needed to heavily alter my previous series of awards last year with my changing interests and responsibilities and finding that I’d need to make even more drastic edits this year I though it time to finally shelve the awards and move to a more general summary of the year.

As with last year my blogging has been even more sparse. In part this is down t having less and less time available and also the fact that I have now written close to 2000 pieces between the Musings, the very old (and now apparently no longer online) Dinosaur index on Bristol University’s system, my Guardian blog and various other outlets. That’s on top of the 1000+ questions I’ve answered on Ask A Biologist as well and it all means that I’m somewhat worn down by blogs. Not that I don’t have a desire to continue, but it’s hard not to rehash existing issues and the most popular areas (bird origins, new species) are very well covered and I struggle to bring anything new or find the enthusiasm a lot of the time.

Still, things are continuing. People might have noticed that the Guardian blog in particular has been in hibernation for around 6 months now. It was originally my intention to quit as while I liked it, there were ever increasing pressures to cover the very areas I had least interest in but a solution was stumbled upon – to draw in additional bloggers and expand this from just dinosaurs to all palaeontology. As such there was a call out for people to apply and the editors are close to making a decision on who will be asked to join me and the whole thing should restart in the new year – stay tuned.

My own new year for 2015 saw me taking a trip to LA for a long overdue break, to see the LACM and its collections, visit La Brea and its tar pits and in particular catch up with Mike Habib and try to finish off some papers. Our work on a new and exceptional Rhamphorhynchus held in Canada is now out, as is out collaboration with artist Matt van Rooijen on wingtip curvature and what that means both ecologically and perhaps systematically for pterosaurs.

Sadly for me this summer lacked any meaningful trips – I’ve been out of the field far too long, and I desperately need to get back to China to finish several projects, but the late summer saw a flurry of activity. First off, rising artist Rebecca Gelernter joined me in London for several months to work on a series of projects as part of her scientific illustration degree. Some of her work (both life reconstructions and skeletal work) will be appearing very shortly in a number of papers for me and John Hutchinson has also put her nose to the grindstone for some illustrations too. If you’ve not seen her stuff before, do take a look at her website and she recently joined Twitter too.

Next was an obvious highlight of back to back conferences: Flugsaurier in Portsmouth and SVPCA in Southampton. The former was the latest in the running series of pterosaurs conferences and saw a superb collection of talks as well as the obvious benefit of getting together people from all over the world to talk pterosaurs. Seeing colleagues and experts you may only otherwise rarely or never see makes it an extremely valuable gathering, even if there were no talks and posters. Still, much was exchanged and much got done and a great time was had by most who survived the weather. As is also becoming a pattern, a volume of papers will also be published from this meeting, and well follow the link if you want more.

SVPCA was a bit more cosmopolitan than usual as several pterosaur delegates stayed on for the second meeting (as had been hoped, each meeting encouraged some people to the other when they would not normally attend) but was also an excellent meeting and gathering of vertebrate palaeontologists. There were some format changes (with more to come) but none the worse for it, and for me it is probably the best annual meeting out there and I love it. Long may it continue, though sadly I look set to miss the 2016 meeting owing to being in Canada.

One other thing that needs a mention for 2015 is the Daspletosaurus paper. This started as a crowdfunded platform that took me to Alberta to work on a very chewed-up skull with Darren Tanke. It took a while but the paper was eventually completed and published and I’m very pleased with the final, detailed study. A lot of people contributed their time as well as cold, hard cash and I’m extremely grateful for all the help that allowed me to complete this research.

Looking ahead, I’m working on what are hopefully the final edits on the Tyrannosaur Chronicles that will be my first book, and there’s a paper on sexual selection in dinosaurs now in press that should be out in the next few weeks. There’s a couple of other works in submission and I’m contributing to the Flugsaurier volume too, so fingers crossed that I’ll have a couple more pieces out next year. That pretty much wraps it up for now. This blog will continue sporadically I’m sure so keep an eye out for new posts.

Flugsaurier 2015 Volume of Papers announced

Published 10/11/2015 Pterosaurs Closed
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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

 

 

Flugsaurier 2015: Portsmouth, UK

Published 11/07/2014 Pterosaurs Closed
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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!

The Archosaur Musings 2013 Awards

Published 31/12/2013 Uncategorized 9 Comments
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It’s getting harder and harder for me to write these sadly, with my ever increasing teaching loads, and broader than ever outreach commitments, I don’t have much time to read as many blog pieces and media coverage as I used to, and a look though a few end-of-year reviews suggests there’s a few discoveries and papers I’d missed which is rather annoying. Still, it is good to at least try and look back over the last year and give a bit of a personal perspective and try and have a bit of fun.

Continue reading ‘The Archosaur Musings 2013 Awards’

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