Sauropod digestion suggestion

I do not normally go in for speculative pieces on the blog and when I have ideas about Mesozoic biology I tend to try and get an excuse to write a paper about them or consult with some colleagues and see what merit the ideas may have. But something popped into my head the other day and it’s been rattling around and I thought it would be fun to put it out there into internet land.

First off, I’ll preface what follows with the important point I’m no real expert on the details of sauropod physiology and digestive biology. So it’s quite possible that I’ve missed some major discussions on this in the literature (or online) be it that the idea is already out there and this isn’t new, or it’s already been discussed and dismissed. I’d also add that while I’ll discuss sauropods here, the central issue may also apply to sauropodomorphs, various other ornithischians and potentially even the bigger herbivorous theropods. I’ll try and boil down the argument as simply as possible, though of course I’m deliberately skipping a lot of nuance.

In short:

Big sauropods would need to eat a lot but allowing for thermal inertia, long digestion times with higher efficiency, and reduced metabolism at large size they have the potential to function without eating 24 hours a day.

For juveniles though, they lack some of these benefits and especially would not have the benefits of long digestion times to break down tough plants. They’d have (proportionally) higher metabolisms and would be getting less return from what they ate.

One solution to this would be coprophagy. And yes, that is what you think it is.

Elephants are a good example here (well without the XXXXeating bit) since they eat a lot of rough material like dried grasses and tree bark. They are bulk feeders cramming everything in, stripping out the nutrition they can and moving on. I was warned years ago when working at a zoo that if offered an apple when visiting the elephant house not to take it. Apparently these occasionally passed through untouched and then would be handed out to unknowing guests. The point is, elephant dung contains a lot of undigested material. If you are a young sauropod, something like that which has already passed through your system and is starting to be broken down could, second time round me a lot more nutritious. And you don’t have to go anywhere to find it, it’s a ready source of calories right there.

That really is the limit of my suggestion. As I say, I suspect I’ve missed something important but I can see an obvious few benefits from this and there’s a good few animals that go in for this practice so it has plenty of precedent. I recognise that reptile and bird waste is often very different from mammals, but then we don’t have many 5 ton lizards that eat ferns around for a comparison and the waste of large tortoises certain can contain plenty of grass shards.

Thoughts below, and if I’ve stumbled across a good idea here I’d be happy to try and expand on it.

Late 2019 roundup

I do try to do a roundup of each year and even with the Musings being more and more infrequently updated, I wanted to keep this up. The year has been very slow so not too much has happened in terms of publications or other news and the major even (the naming of Cryodrakon) I did manage to give some good coverage. My only other publication was a response paper written with Tom Holtz that argued (again) that some of the evidence suggested for highly aquatic lifestyles of various spinosaurs are overstated or at least much more complex than sometimes stated. Once again (see also adult dinosaurs, social behaviour etc.) this is at least in part an issue of definitions and the turn of phrase ‘semi aquatic’ which covers a vast range of behaviours and selective pressures and degrees of adaptation being used without anything like enough specificity.

I do now have a whole bunch of papers in review and a couple that are (provisionally at least) accepted and should be out this year, and so while the Musings is likely to carry on being generally quiet there will be some research to talk about with any luck. Most of that will be pterosaurian in nature but there’s some dinosaur stuff in the works as well.

Also coming at some indeterminate point are some new books. I’ve all but finished a first draft for my next popular science book that should be out sometime this year (probably late autumn) and I’m also involved in a couple of others so stay tuned.

In the meantime I am still posting photographs and micro-updates on projects on my Facebook page and this is the best place to keep up day to day, but I’ve no intention of shutting down the blog even if the posts will be sporadic.

Happy New Year.

 

 

Hone, D.W., Habib, M.B. and Therrien, F., 2019. Cryodrakon boreas, gen. et sp. nov., a Late Cretaceous Canadian Azhdarchid Pterosaur. Journal of Vertebrate Paleontology, 39(3), p.e1649681.
Hone, D.W.E. and Holtz T.R., 2019. Comment on: Aquatic adaptation in the skull of carnivorous dinosaurs (Theropoda: Spinosauridae) and the evolution of aquatic habits in spinosaurids. 93: 275-284. Cretaceous Research.

Many more Cryodrakon images

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.

Pairi Daiza Zoo

Sleeping Tasmanian devil

My most recent zoo outing was the Pairi Daiza collection in Belgium. I’d not actually heard of this place until finding a flyer for it in a hotel in France but was drawn to its claim of having won two ‘best zoo in Europe’ awards (from who I don’t know) clearly being very large and the fact that it has somehow passed me by. I managed to have a chance to go recently however so made the trek out to it and found what must rank as one of the strangest collections I’ve ever been so, so strap in for a pretty long and detailed review.

First off the basics, the animals were numerous, generally well cared for (though a couple of terrariums in the reptile house were poor and one alligator was rather badly overweight) and in good set-ups. There was lots of space and with well managed environments and the animals appeared to be doing well.

Young gharials

As usual, it’s worth touching on some of the more interesting and rare animals since these days going to a zoo and seeing a lion on Celebes macaque doesn’t really do much for me (or I suspect, many of the readers). So, I got to see blesbok, rufus hornbill, Tasmanian devils, and potoroos (all wonderful), a displaying Bulwer’s pheasant (amazing), Spix’s macaws (well, sort of, they were in nest boxes but I could see a bit of one) and best of all, gharials! Only a pair of very young juveniles, but still an utter delight to see and something I’ve been after for many, many years.

There were lots of other cool things too (especially on the bird front), giant pandas, lots of pheasants, parrots and touracos, shoebill, bird of paradise, spotted hyena, cock of the rock, hummingbirds, couscous, and a really wide selection of classic big things (giraffe, rhino, hippo, apes) as well as less-often seen ones like moose, bushbuck and various vultures. There was a lake with lots of wild waterfowl and then sections were partitioned off for the seals and penguins which was nice, and then a good reptile house and aquarium, and several walk-through sections, but here is where things start to get odd.

Potoroo

The zoo is fundamentally constructed in a very odd manner. It is absolutely huge and built mostly up the side of a huge hill, and it is signposted badly when meant for a very long day (more than a few shades of LA Zoo). There’s lots of bizarrely wasted space such as a walk through tropical house with a massive waterfall and lake and a rope-bridge over it, but no fish or other animals in the water or on the little islands in the middle. It looks nice, but there’s no animals to see in that part, they’re all at the other end. There’s big laws which clearly are in part there for corporate events (there were a couple on, even at the weekend) but it only adds to the spacing out between exhibits. Much more than that though, huge chunks are given over some kind of tribute to the homelands of various animals. There is, for example, an absolutely huge and basically full-sized Thailand temple on top of the hill. It’s utterly huge and very detailed, but, and this is quite crucial, it’s not part of the exhibits. It’s not a huge façade to the elephant house, or is the small mammal house, it’s literally just a huge replica of a temple. There’s a Chinese one next to the pandas as well, and a fake warehouse with a real seaplane in it and canoes next to the bears and moose. It’s basically a huge amount of land taken up with a very expensive (and really quite faithful) replica of major buildings.

Similarly, the aquarium is themed around captain Nemo’s Nautilus with steam-punk type copper piping everywhere and gas lanterns etc. and even a control room with a very poor mannequin propped up again a steering wheel. The reptile house is built inside a mock Victorian steam ship that’s sinking (the whole thing is built on a slant) with the theme of the animals escaping from their containers. There’s even a fake lighthouse over the seal pond (which at least houses an icecream stand but otherwise seems to be functionless).

Blesbok

It’s all just set dressing, and while it mostly looks nice, I really can’t see the point. It must have added a colossal amount to the cost of the zoo and takes up a monstrous amount of space and it really adds not that much. These reviews as a whole are coming from a place where I’m both a huge animal enthusiast and someone who has been to a lot of zoos. I absolutely recognise that things that appeal to me as a visitor may not appeal at all to the average zoo goer but I’d hope I have enough empathy to know why they love seeing elephants and ring tailed lemurs even when I’m more interested in elephant shrews and ring tailed cats. But here’s the thing, the visitors (and there were many) didn’t seem that bothered by it either. They were mostly looking at the animals and the small sections of pseudo-museum exhibits there were plugged into a couple of these were completely empty. I really can’t fathom why they would do this, and it only adds to long walks to get from section to section and confusing detours when trying to get past them.

Bulwer’s pheasant displaying

The zoo was also rather expensive to get into (more than London Zoo by a margin which obviously suffers in part from being in London) and then the carpark was a lot on top of that. Given that it’s absolutely in the middle of nowhere in the country where land is cheap, and there’s no other real mechanism of getting there (I didn’t see any bus stops or any public transport coming or going) this seems an utterly unnecessary and mercenary addition.

So, how to sum up? It’s an amazing collection with lots of great exhibits and a mix of the ‘traditional’ animals and lots of real rarities and things that would appeal to even rather jaded zoo goers. But it’s a huge amount of ground to cover and the huge and badly signposted gaps between exhibits is frustrating and coupled with the price and inaccessibility means it’s not a trip for the casual visitor (unless you already live in rural Belgium).

 

Linton Zoo

Eastern quoll

I’m really very behind on blogging generally and my zoo reviews in particular (if you haven’t seen it, you’ll want to read this thread on Twitter as to why). In addition to a couple of small outfits and revisits, I’ve made it to four notable collections in recent months and not written a word about any of them. I’ll start with one of the more recent and certainly the smallest of them, Linton Zoo in the Cambridgeshire countryside.

Linton is small by any zoo standards and even really taking your time, it’ll fill only half a day but it is not like some of the smaller provincial collections that dot the UK countryside. Too many of these are underfunded and rely on some pretty basic ‘stock’ animals which while probably interesting for the average visitor are a list of species I’ve seen too many of and are not especially exotic (you know the score, squirrel monkeys, llamas, African grey parrots, a reptile house of leopard geckos and royal pythons, and so on). However, while inevitably there’s a few very common species here, the collection has some ‘proper’ exotic animals – kangaroos, some big cats, ground hornbills, giant tortoises, Brazilian tapirs etc. and some excellent rarities.

Lesser hedgehog tenrec

I went primarily because, listed on their website, were quolls. I wasn’t aware of any in Europe, let alone in a small zoo and yet there they were a lovely set of Eastern quolls that were active and about and were a delight to see. Also on the odd mammal front, there were a pair of lesser hedgehog tenrecs so two huge ticks right there. One last thing was the binturongs, real favourites of mine but with a tendency to sleep quietly in a box and be as near to invisible as it’s possible but here mum and two mid-sized offspring were all out and enjoying the autumn sun which was a real joy.

Juvenile binturong

Their bird collection was also good, with two more new species for me, red-tailed black cockatoos, and a blue throated macaw as well as several of the rarer Amazon parrots. Plus, an ever favourite of mine, several touracos including one that sat very conveniently on a branch near the wire so I could take some good snaps of it. Finally, to round it out there were a few life-sized dinosaur models scattered around the grounds. These were a bit out of place to be honest, but they were mostly pretty good and at least had some accompanying labels.

Red-tailed black cockatoo

Overall this was a great little set-up, obviously I’d have preferred something larger and the tiny reptile and small mammal houses were in the process of refurbishment meaning there was almost nothing to see there (tenrecs aside) which was a bit of a shame. But the enclosures had that nice balance of cover and security for the animals with real space for them, and also good viewing points. It is probably a bit out of the way for a lot of people and the size might reduce its draw but to visit such a small collection and see half a dozen species new to me takes some doing and I’ll certainly be going again sooner or later.

 

Welcome Cryodrakon – a giant Canadian azhdarchid pterosaur

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

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

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

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

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

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

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

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

The problem with floating pterosaurs

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

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

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

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

Hypothesised floating postures fo various pterosaurs

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

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

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

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

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

 

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

A simple, but important, request to all readers

I’ve now been blogging for over 10 years and I’ve also written plenty of other news articles, appeared on TV, radio and in podcasts, and done whole rafts of talks and events as well as writing a book (here’s a huge list of links to things I have done) and consulted for plenty more too. I do this because I enjoy it and I think it’s very important for scientists to help engage with the public and explin what they do and what they have learend and why (and even more so when it’s research based on public money). It’s nice to get recognised for this kind of work but it is not why I do it.

However, at least some of this work is now undertaken as part of my job at Queen Mary University and so I need to try and get a handle on what I am actually achieving. So, as a result, I have a small but very important request. If you have literally 1 minute and have read my book, seen one of my talks, read a blog or article I’ve written, listened to a podcast I did, saw a TV show I consulted on, sent me an e-mail that I replied to, chatted to me at  science festival, or really anything at all from my outreach programs, please do fill in this tiny form. It’s really important for me and does take seconds. Please also share this far and wide with friends and family, I know I have hundreds of subscribers to this blog but my book has sold over 10 000 copies and some of my videos or podcasts I know have had audiences in the 100 000s so I really hope this message can spread far and wide and reach those who do not read this blog.

I don’t ask for much on here, so please spare me a minute of your time to fill this in and to share the link, retweet it, post it to a messageboard, or anywhere else some people may see it who like their dinosaurs.

(Somewhat late) roundup of 2018

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

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

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

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

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

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

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

A new venue

Becuase writing the Musings annd being on Twitter (and perviously doing the FLugsaurier blog and pages, and Ask A Biologist, and The Lost Worlds for the Guardian) isn’t enough, I finally decided to start up a proper page on Facebook. So if you want to follow me there and post soem dinosaur stuff and get more involved in discussions and research then hope over here to Dave Hone’s Dinosaurs page.

I’m still doing other outreach things like talks, consultations for documentaries and podcasts (here’s a very recent one on pterosaurs) and I’m writing a second book so there’s still lots more going on. But this new page will, I hope, allow me to engage with a different audience in a different way so do please go over there and like the page and share it around.

 

Pteranodon vs Cretoxyrhina

Shark vs Pterosaur. By Mark Witton.

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

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

‘Complete’ Pteranodon at the LACM.

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

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

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

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

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

 

The paper is fully OA and available here.

 

Interview with Gabriel Ugueto

Gabriel is a real newcomer but has smashed into the palaeoart scene with his huge productivity levels meaning his artwork is already everywhere online and in books and in concert will all kinds of media and palaeo projects. There’s already a mountain of his material and more is coming as he talks about his book plans below.

Tyrannosaurus ‘design’ done for ‘The Real T. rex’

How long have you been an artist?

I have been drawing since I can recall. I was thinking about this the other day, and I realized that I do not remember a time in my life when I was not drawing or painting. I have always loved drawing, I have always loved animals, and I have always loved drawing animals, so I guess it was a natural progression for me to become a scientific illustrator and paleoartist.

Chasmosaurine phylogeny

How long have you been producing palaeoart?

I am a newcomer to the paleoart scene. I have only been seriously involved in producing paleoart for the last three years, but in that time I have been fortunate enough to have won the praise from numerous paleontologists and several fellow paleoartists that I truly admire. I have worked on some really interesting projects that include books, scientific papers, art for museums, magazine articles, and even the TV documentary “The Real T. rex,” in which I got to work with you in the concept art that was used to generate the CGI Tyrannosaurus rex that appears in the program. I studied graphic design and illustration, and the road to becoming a paleoartist has not been straightforward. Before entering the world of paleoart, I was doing other types of graphic art, including scientific illustration. For several years I was also an independent herpetology researcher, and I authored numerous papers including the description of several new species and genera of neotropical lizards. During that time most of my scientific illustration was concentrated in herpetology. As time went by, I started getting more and more requests to illustrate various types of reptiles and amphibians. The world of herpetology is intrinsically linked to paleontology, so I consider my incursion into paleoart just a natural extension of my work as a scientific illustrator. Eventually, enough people were asking me for commissions that I could start working as a full-time freelance paleoartist and scientific illustrator.

Titanonophoneus

What first got you interested in dinosaurs and art?

I grew up in Venezuela in a family of nature lovers, so I was surrounded by numerous field guides and other animal books, as well as by the diverse local fauna. Thus, I was exposed to animals constantly in one way or another, and they very quickly became the most important subject for my art. I was not only fascinated by extant creatures but extinct ones as well. Dinosaurs and other Mesozoic reptiles were among the first animals I remember drawing, and I was completely mesmerized by them. My oldest brother (who is my elder by 19 years) was studying geology when I was a little kid so there were all these books about geology and paleontology laying around in my house. I used to spend hours reading those books and drawing the various extinct animals that appeared in them.

Thylacoleo

What is your favourite piece of palaeo art that you have produced?

My favorite piece is always the one I am currently working on, or the one that I am planning to do. It is that drive to create something new that keeps you going, hungry, and interested as an artist. I think that is the case not only in paleoart or scientific illustration, but in every line of creative/scientific endeavor. Currently, I am largely focused on finishing my book “Journey To The Mesozoic vol. I.” In it, I would like to take the readers on a journey around the world during the Triassic and Jurassic periods, visiting 33 geological formations and seeing reconstructions of over 600 tetrapod species that lived during that time. Some of those reconstructions include several well-known dinosaurs like Diplodocus, Stegosaurus, and Allosaurus, but also numerous, more obscure and extremely interesting creatures. So, my book and the reconstructions I have produced for it, are currently my favorite pieces of paleoart.

Niobrara fauna

Who is your favourite palaeoartist or piece of palaeoart?

There are many paleoartists who have been, and continue to be, sources of inspiration for me. Among those, I can name five who have been fundamental in influencing and inspiring my work. Douglas Henderson has created some of the most beautiful scenes in paleoart, with masterful compositions depicting animals in a very natural way. I am particularly fond of his reconstructions of Triassic animals and environments. John Conway has been a major influence on me regarding depicting exciting hypotheses in an artistically interesting way. I also deeply admire the wonderful art by Mauricio Anton. His magnificent and detailed illustrations of (primarily) extinct mammals are, in my view, some of the best depictions of that group of vertebrates ever created. Matthew Martinyuk reconstructions of maniraptoran dinosaurs and pterosaurs, done in a simple but thoroughly researched, field guide style, have also been very influential for me. As have been the beautiful, atmospheric reconstructions of appropriately feathered maniraptoran dinosaurs by Emily Willoughby.

Assorted sauropods

What is your favourite dinosaur / archosaur?

I get this question on social media all the time, and I always answer it the same way: I cannot choose just one because there are so many of them that I find so interesting, including all extant birds and crocodilians. In all honesty, I think I am slightly partial towards theropods, but recently, my love for various pseudosuchian groups has grown tremendously. Many of them, like poposauroids and metriorhynchids have become some of my favorite art subjects.

Deinocheirus and Alioramus

Is there any animal you would like to paint but have not?

There are a lot of them, maybe too many to list. Also, I am always interested in revisiting animals that I have reconstructed in the past, viewing them from a different point of view or perspective.

Dimorphodon

What do you think is the most important part of good palaeoart?

In my view, good paleoart should make the viewer feel the subject you have depicted as an animal that could be alive. Secondly, good paleoart should be effective in helping general audiences understand the latest scientific research and hypotheses. Finally, good paleoart should never showcase extinct animals as blood-thirsty, psychotic movie monsters. Sadly, the world of paleoart is over saturated with reconstructions of dinosaurs and other Mesozoic reptiles running around or swimming with their mouths wide open, a maniacal look in their eyes, and blood spilling everywhere. Sure, gory scenes occur in nature, but they are not nearly as interesting or common as other parts of the daily life of any animal. Images like that just help reinforce the view of dinosaurs and other extinct animals as kaiju. For me that is the equivalent of a tabloid story. Simply yellow press or click bait at its best based on little or no real truthful information.

Shuvuuia

You can follow Gabriel on Twitter here and Instagram here and his website is here.

 


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