Posts Tagged 'Pterosaurs'

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.

 

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.

 

Archosaur Musings 2015 Roundup

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

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

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

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’

A very Brazilian pterosaur

Back in 2010, the Pterosaur.net boys and girls descended on Beijing for the Flugsaurier meeting. A good time was had by all (well, as far as I could tell) and while pterosaur researchers generally get together to argue, one of the things that was sorted out was that the next meeting would be in Brazil in 2013.

The conference fieldtrip in China included many a long drive in a minibus to get between the various localities and museum in Liaoning. On one of these journeys I had (what I thought) was a great idea for Brazil and John Conway was unfortunate enough to be sat next to me and feel the full force of Dave explaining his new concept. However, fortunately for me, John loved it and went with it. We pitched it as a possible logo for the conference and while they have picked their own (which is lovely) they have included our effort (I say ‘our’, John did the whole thing) on their pages, so it seemed an appropriate time to post this to a wider audience.

In my head I had the idea of pterosaur heads being bold and colourful, and that’s very true of the Brazilian flag. Add to that the huge size of some of their crests and at least one Brazilian genus, Tupanadactylys, that was big enough that it could pass for a flag at the right angle and with a bit of imagination. So here it is, a truly Brazilian pterosaur.

Darwinopterus redux

So after the comments both on here and over at Luis’ new blog, Luis has sorted out the trimmed branches problem with a new tree trunk. The result is above.

As a ‘bonus’ here’s my original sketch of the critter that I sent to Luis. I’m no artist and it was done quickly, but hopefully conveyed the essence of what I had in my mind. The psychedelic colours were not a guide for Luis, but to try and make it clear which parts of which wing membranes went where – if just black and white, it was rather a mess and things were a bit confused.

My very own Darwinopterus

As readers will remember, a couple of weeks back I dropped in on Luis Rey to talk over dinosaurs, pterosaurs, classic rock albums and help him get a blog up and running for his new artwork. Inevitably the conversation at one point turned to thinks Luis hadn’t yet done and things I was interested in seeing. I noted that for all the raft of pterosaurs Luis had thrown out in recent year, neither Darwinopterus or any of it’s close relatives had made it into his collection and given the novelty and importance of these taxa, it should surely be high on the priority list.

Luis simply suggested I sketch what I had in mind and he’d have a go. The turn around was rapid and the result was beautiful and here it is already:

I sent Luis some images of the wonderful Darwinopterus robustodens specimen as a source for proportions and general anatomy and produced a sketch of the posture I wanted. I can’t remember ever having seen a picture of a pterosaur about to land on a tree and that’s what I went for. I’ve seen plenty of them in trees, flying between trees and even taking off, but not in the act of landing. I’m also a big fan of unusual image shapes for art and love things that eschew the normal A4-type proportions, so I specifically asked for something very tall and thin to emphasise the height of the tree and the wingstroke. Anything other than that is shackling the artist (especially when it’s Luis) and something I don’t like to do if I can avoid it, so I said nothing about colours, patterns, background etc.

Anyway, here it is (and here it is on Luis’ pages). My massive thanks to him for his work and for crediting me with far too much. Head over there and tell him how awesome it is for me.

A post about a tail with no pun in the title

So onto the last major post about Bellubrunnus – the tail. The tails of rhamphorhychines are interesting as they have a somewhat unusual anatomy. Just like the dromaeosaurs (though obviously, convergently acquired) rhamphorhynchines have elongate zygopophyses and chevrons that overlap multiple vertebrae and bind the tail together so that it is a relatively stiffened structure. These extensions are basically rods of bone, and can long enough to overlap the four or five adjacent vertebrae to their origin.

However, Bellubrunnus appears to be unique among rhamphorhynchines in lacking these structures. It still has zygopophyses and chevrons (as can be just about seen in the figure) and compared to some pterosaurs at least these are long, but they are a fraction of the length of other closely related species. This begs the obvious question, of what happened – are these really reduced or is there some other factor at play? Well, there are a number of possible hypotheses to explain this and here I’ll go through them and why we have come to the conclusion that this is a genuine feature. Not all of the chevrons are there for sure, so some have been lost or remain cryptic for whatever reason, but several are quite well preserved and so the below discussions refer to the issue of the size and shape rather than presence / absence of chevrons.

First off, were these simply not properly ossified prior to preservation and were there, just as unpreserved cartilage? This seems really unlikely, even the smallest and youngest specimens of Rhamphorhycnhus (which includes specimens even smaller than Bellubrunnus) have fully ossified chevrons and zygopophyses. These seem to be present at a very early age in the pterosaurs that have them and so it would be odd if they had a different ossification pattern here. Indeed it would be doubly odd since if anything, Bellubrunnus has better ossification of its elements than is usual for small pterosaurs, with well-preserved and ossified tarsals and sternum. So it is far more likely that they are fully ossified, they are just much smaller.

Could these have been lost through decomposition or disassociation from the specimen, or may not have been preserved even if they were ossified? While a few pieces have begun to disarticulate and move (the gastralia and a few dorsal centra and the prepubes) nothing else on the specimen has really begun to move and indeed the caudal vertebrae as a whole is well articulated. It would be odd indeed if the only thing to have rotted or moved was the chevrons or parts of them, while the rest remained intact and complete. Similarly, with even tiny parts like the delicate palate and gastralia being preserved (and indeed at least a couple of chevrons) it also seems unlikely that these somehow resisted preservation when everything else is there. Certainly it’s possible, but even so, some are still there and the loss of many chevrons would not affect the shape of the ones that have survived and wouldn’t affect the zygopophyses.

Were these destroyed or modified through preparation? This is a tricky one to answer, but again, there’s no obvious reason to think so. The preparation job is superb (look at the skull!) and was done with great care and attention to detail. It’s always possible that thin and delicate structures were lost, but while the matrix has been all but scraped clean, at least some have survived (and again lots of other delicate things) and I find it hard to imagine they were modified in such a consistent manner.

Are these genuinely distinct then? That is the obvious conclusion given the problems with the other hypotheses. However, there is more than just negative arguments against these other ideas, but there are reasons to positively support the idea that these are genuinely short. Although greatly reduced in length, the anatomy of both the zygopophyses and chevrons is otherwise well consistent with the anatomy of these features in other rhamphorhychines. The zygopophyses are rather rod-like and then taper abruptly to a point, just as we see in others, only with a much shorter rod. And similarly the chevrons are long and thin and splint-like, terminating in a point at each end, just as we see in others, only again being rather shorter.

While as noted we are rather short of chevrons for whatever reason, those that remain and indeed the zygopophyses seem to have a genuinely distinct morphology to other rhamphorhynchines, including similarly small and young specimens of Rhamphorhycnhus. This then is a major anatomical difference that separates Bellubrunnus from its nearest relatives as well as providing a little more interest and intrigue in the origins of this structure since while it is present on all other rhamphorhycnhines, it’s also present in basal pterosaurs outside the group and so may well have had multiple origins and losses.

Brunn – not the Solnhofen

At the end of my last post I raised a most significant point – Bellubrunnus isn’t a Solnhofen pterosaur. While it’s easy to think that those Jurassic lithographic beds from Bavaria are the Solnhofen, it’s not the case. Like all rock records, different divisions are known and are grouped in various hierarchical clusters. The Solnhofen is home to a lot of important species (Archaeopteryx for starters, not to mention all the pterosaurs and insects and plants and fishes) and a good deal of work has gone into working out the stratigraphy of all these different fossil-bearing beads, but not all lithographic limestones lie in the Solnhofen.

Obviously this doesn’t mean that an animal from one layer right above or below the Solnhofen didn’t overlap in time with other strata – the rocks don’t delineate when and where species lived. However, Brunn is rather older than even the oldest Solnhofen beds and from the Kimmeridgian rather than the Tithonian. While the rocks are of a similar kind and were put down in a similar manner in similar ecosystems, the two are different.

Work on the Brunn beds are still very new and I must confess I’ve not looked into it in any great detail (not least as all the literature seems to be in German) and have had to rely heavily on my colleagues here. Still, the two do seem to contain different taxa as a whole and while to date the higher vertebrates at Brunn have been few and far between, given the quality of the preservation, I don’t think there’s any reason to expect that we won’t get a lot more in the future. Moreover this does suggest that Brunn is different to the Solnhofen and so we might expect a different (if closely related) fauna to be present. In short, the fact that we now have literally hundreds of pterosaurs from the Solnhofen and no record of Bellubrunnus there, supports the idea that this is a different genus, and also the idea that there might be many more new pterosaur species in there to be found. At the very least, there is a lot more to learn from the Brunn biota.

One last point to address here lies in the temporal distribution of rhamphorhycnhines. The recently described Qinlongopterus is also known from a single, small, and young specimen, though it heralds from the Middle Jurassic of China. As described this taxon is really rather similar to Rhamphorhynchus and it was suggested that as such, the rhamphorhycnhines might be really rather stable as a group and went long periods of time with little morphological change. Obviously Bellubrunnus interrupts this apparent trend, as compared to the Middle Jurassic of China, it’s much closer in time and space to Rhamphoprhynchus, yet does have quite a few differences. This is probably due to that fact that unlike Bellubrunnus, Qinlongopterus is really badly preserved, and morphological information is rather limited. What can be seen in Qinlongopterus is very Rhamphorhynchus-like, but that’s not saying much since the condition of it means that not all the many details can be seen. Plus of course the young of species tend to be much harder to tell apart than the adults, since, well they don’t have all their adult features yet and typically the younger they are the harder that will be. So in fact this ‘stability’ is illusory based on the age and condition of Qinlongopterus and in any case is interrupted by the emergence of Bellubrunnus and its differing anatomy.

And on that subject, next up, that interesting tail…

Bellubrunnus – definition, diagnosis, and why it’s not Rhamphorhynchus

Right, lets crack straight on with dealing with the details of this lovely little thing. First off, if you have read this post on pterosaur ontogeny, you should be able to recognise that while Bellubrunnus is small (in fact it’s tiny, with a wingspan under 30 cm and a skull just a fraction over 2 cm), it’s also very young. The head is proportionally huge, and the eyes (represented by the sclerotic rings) are massive too, lots of neurocentral sutures are open (as can be seen by displaced centra in the dorsal series) and the wrists, pelvis and scapulocoracoids are unfused, and even the skull is coming apart. Unusually for such a small pterosaur though, the tarsals are well ossified, though they are rather amorphous in shape, which is a classic feature of young pterosaurs.

This then is a very young animal. That does of course complicate issues a little as obviously some things change during growth and we don’t want to misdiagnose this by thinking it has some unique features which are in fact simply a result of its age. On the other hand though, following mostly from the work by Chris Bennett, we have a good idea of the ontogenetic changes undergone by Rhamphorhynchus as it grew so we do know what kinds of things change as they grow (and so can be avoided, or used carefully) and which don’t (and can be used pretty freely).

Lets start with the most obvious thing – Bellubrunnus is a rhamphorhynchoid pterosaur. It has a proportionally small head (compared to the size of the animal as a whole, and the body specifically), short neck, short wrist and pteroid, short metacarpal IV, long tail, long 5th toe and other characteristics. Moreover, it’s also a rhamphorhynchine – a derived member of this basal assemblage and close to things like Rhamphorhynchus and the recently described Qinlongopterus. Bellubrunnus exhibits a number of characters associated with this clade such as the shape of the deltopectoral crest and the proportional length of the wing finger.

Bellubrunnus is also really rather like Rhamphorhynchus which might be no surprise given the rocks it heralds from (though more on this later) – the area is kinda famous for producing specimens this genus in serious numbers. The two share a number of characters previously used to diagnose the latter alone such as edentulous jaw tips, a femur shorter than the humuers, and an H-shaped prepubis. However, the two also have some rather notable differences that clearly mark them as different taxa. Among other things, Bellubrunnus has only 22 teeth (or perhaps even fewer) compared to some 34 in Rhamphorhynchus, it has a rather different tail anatomy (more on this to follow as well) a different humeral shape, and several major proportions of the limbs are quite different.

The point about proportions is quite a significant one. Proportional ratios between various elements are common characters for pterosaur taxonomy and systematics, but unhelpfully, we also know that some of these change during ontogeny in at least some groups. So we do need to be careful and this is no exception. The best example here is the ratio of the humerus to the femur – in Rhamphorhynchus this seems to get larger as the animal gets bigger. Small (and so young) specimens tend to have a lower ratio and adults a high one. Bellubrunnus is among the smallest pterosaurs known and comparable in size to the smallest (and youngest) specimens of Rhamphorhynchus, but it’s ratio is the higher than any specimen of the other genus.

While I’ve not mentioned it here, in the paper we do compare this to other members of the rhamphorhynchine clade and provide similar numbers of difference in things like tooth count, anatomical features, skeletal proportions and the like. A number of these taxa are rather fragmentary and hard to say too much about, but do always differ from Bellubrunnus.

So in short while we can be sure this is a very young animal, we can also be confident with our assignment to the rhamphorhycnhoids and rhamphorhynchines, and while this would appear to be a close relative of Rhamphorhynchus, it’s also clearly quite different in a number of characters, marking it out as a new and distinct taxon. One last point needs to be raised here too as a launch-pad for the next post, Bellubrunnus is from Brunn, and Brunn, well it’s not actually part of the traditional Solnhofen that is home to Rhamphorhynchus. It’s older and the two were not contemporaneous.


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