Search Results for 'protoceratops'

Guest Post: Producing Protoceratops art

The little ceratopsian Protoceratops (and indeed art on Protoceratops) has been a big thing for me in recent years as I’ve been lucky enough to work on some very special specimens and have them illustrated in life.  As is so often the case though, one new specimen begets some new opportunities and today sees the publication of a new paper on the ongoing issue of sexual selection and social dominance signals using some of these specimens in the dataset. The paper is freely available online here and I’ve also written about it here, but the paper also contains some lovely new palaeoart of signaling dinosaurs by Rebecca Gelernter who has kindly agreed to talk about her work here.

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When I plan a piece of paleoart, I try to make the animal I’m restoring as complete as possible. I want to make it look like a real, tangible creature with adaptations that make sense for its life history. I particularly enjoy showing behavior, which made this a really intriguing project to work on.

First off, I had to figure out what my Protoceratops should look like. Anatomically, this was pretty straightforward, thanks to the wealth of fossil photos, papers, and books Dave had on hand. Factor in his enthusiastic feedback and that’s all the background you could ever need. At Dave’s request, I was depicting the animals without any filaments or other non-scale integument, so after familiarizing myself with the fine points of ceratopsian feet and beaks, all that remained was to design the color scheme.

Proto Sketches

I decided that the facial markings should be only part of the body with elaborate markings, as the frill and jugal bosses were proposed display structures. When designing markings for extinct animals, I like to thumbnail several different possibilities based closely on living creatures and remix them into something new. For Protoceratops, I mostly looked at antelope facial markings, and the final design features elements of bongo and sable. The jugal bosses are an eye-catching white, and the all-important frill is a splash of those ever-popular display colors, orange and red. I imagine that the animal would flush the frill with blood during an encounter with a potential mate or rival for flashier color. I used a camouflage-friendly beige for the animal’s base color, broken up by a line of darker splotches down each side that become bolder and more regular on the tail, another potential display structure. I used white again on the tip and ventral side of the tail to create a starker contrast, with more orange to draw attention to the ridge formed by the tall neural spines.

Proto-Color

Dave asked for the piece to show two adult Protoceratops having a confrontation, while a group of less flashy subadults goes about its business in the background. I selected a pose that showed off the display structures: tail up, frill angled toward the other individual. I angled one adult’s head toward the viewer and one away to show that the display colors are limited to the front – no point wasting resources to color the side of your head that you can’t show off. I wanted the piece to be taller and narrower than your standard portrait orientation, so I raised the point of view above the two main animals and arranged the background players some distance away on another dune. Dave suggested adding the crisscrossing footprints in the staging area to suggest that this type of interaction has happened there before. I placed the animals in a particularly empty bit of desert, with just a few small, scrubby plants in the background.

I’d recently gotten good results from painting over a graphite drawing in Photoshop, so I was eager to try that again. There are different ways of doing this, but the technique I usually use is to set the graphite original to “multiply” and leave that layer on top, painting on a few different layers stacked underneath it. It’s an interesting change from using purely traditional media, and I’m looking forward to trying new things with it.

So there you have it: my process for making (definitely) accurate, (hopefully) interesting paleoart. If you’d like to see more of my work, I’m on all the usual sites under the name Near Bird Studios.

Protoceratops take shelter – new palaeoart

Although PLOS has many things to recommend it, one thing they don’t do is give you a lot of notice about publication and so actually the production of my recent paper on Protoceratops came shortly before the manuscript went online. As a result, although the paper had been around in various guises for several years, it was a bit too short notice to have everything ready for its publication, including both a press release from me and the following artwork.

protoceratops juvenile-correct1The superb illustrator Andrey Atuchin had very generously got involved in producing an illustration to come out alongside the paper, but his recent illness coupled with the limited notice put everything back. However, I am delighted that he has now completed his new work and allowed me to put it up here.

Above is a simple (but fantastic) vignette of a single Protoceratops. This represents the age class of the block of four young animals that were the feature of the paper, with the reduced size of the frill and the overall proportions of the animal that does differ from what we see in adult animals. Although juvenile dinosaurs are often rare, there is a natural tendency for only full adults to be illustrated, or we see young animals only in the context of their parents or part of a herd and it’s great to be able to focus on a single animal, especially when the adult is already so familiar.

Protoceratops final artwork01

This then makes the whole composition below rather unusual and of course very fitting for the paper. We see the group of juveniles together, devoid of adult supervision or as part of a herd but in their apparently natural aggregation. The environment of course reflects the Mongolian Late Cretaceous with a very sandy region and little real plant life. The overall composition though hints at the wider issues of the paper in a nicely understated way – the group are largely at rest, though remain vigilant and the fact that there are multiple individuals means even those not directly scanning the environment are not that vulnerable and the group as a whole are looking in multiple directions. Staying vigilant is especially important for young and vulnerable dinosaurs lacking the size, experience and defences of adults, and so they must with here a pair of Velociraptor on the horizon.

My thanks of course to Andrey (who retains the copyright on these, please don’t share without permission) for this wonderful rendition of group living in the Cretaceous and nice of him to sneak some theropods in there so I can forget about my fall from grace and pretend that this is not just about ornithischians. It’s a wonderful piece and it really does convey not just the contents of the paper, but the issues at the heart of it, and even if you disagree with the hypotheses, it’s certainly evocative and really does show the concepts magnificently.

 

 

 

 

A block of baby Protoceratops

C skull IIMy new paper is out today and it describes a wonderful new specimen of four baby Protoceratops together in a single block. Unlike many other groups of exceptionally preserved specimens from the Mongolian Gobi, the animals are effectively stacked on top of one another and all facing in different directions and importantly, their inferred age is different to other Proto specimens.

This specimen was actually collected in the early 1990s, something I hadn’t realised when I saw it in 2011 in the Hayashibara museum in Japan. This was my second trip to the museum after having been in 2009 (that led to the Tarbosaurus bite marks paper) and this was the specimen that really grabbed me and I am obviously most grateful to co-author Mahito Watabe for allowing me to lead the paper on this.

The preservation is superb, and although there’s been some erosion and damage (especially to the uppermost animal) at least one of them is brilliantly exposed and almost immaculate in condition. At this point I must praise the preparator for his incredible work here, this is a huge block (close to a metre cubed), the matrix is exceptionally soft and brittle and the organisation of the specimens must have made the whole process extremely difficult and the result is both beautiful and impressive.

Block view upper front 10cm

There are two major aspects to the paper (which is in PLOS ONE so for all the details and tons of pics so you can read it all there) and I’ll deal with them in separate posts. The first one is the block itself and the implications for Protoceratops generally. There are a number of groups of this dinosaur known already – several sets of adults, a pair of subadults (also briefly covered in the paper – and shown below) and a set of very young animals that were described a few years ago as something close to hatchlings in a nest. In the paper we actually suggest that these were not in a nest, but free living, but the wider point is that we have similar sized animals (that are probably of a similar or the same cohort) together at multiple different life stages, and we don’t seem to see mixed cohorts as with many other dinosaurs.

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The block here slots into this pattern beautifully, the animals are about twice the length of the smallest ones, and about half the size of the subadults. That means we can put together a sequence of specimens at four pretty distinct life stages where we have groups of animals together at different times of their lives. That is something we have not been able to do for any extinct dinosaurs before – we do often have groups together and often of adults or juveniles or the two mixed together, but we are not aware of a so many obviously different cohorts of a single species showing this. Wonderfully, these are not all just Protoceratops, but all P. andrewsi and even better all of these are from a relatively narrow time and space window.

As non-avian dinosaurs go, that’s about as close to a single population as you are really going to be able to find, so collectively we are inferring that this was a pretty normal behaviour for this population. That sounds like a pretty conservative approach (can we not apply it to the genus or species as a whole?), but I think it’s something we really need to do a lot more of in palaeontology. The sheer variety and plasticity of many behaviours, especially when it comes to forming groups, means that is probably dangerous to extrapolate without some good supporting evidence and that sets things up quite nicely for the second post which will follow tomorrow.

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Protoceratops

Protoceratops hasn’t done too badly on the Musings, though this is by far the best specimen I have been able to show on here to date. This taxon is basically synonymous with the Asian Late Cretaceous with huge numbers of specimens having been found and a great many of them complete. With so much material (well, prior to the Liaoning revolution anyway) coming out of Mongolia and China it became a standard feature of pretty much every dinosaur book going (and don’t forget to include an Oviraptor running off with a few eggs). Even so, there are rather obvious and quirky features that are rarely illustrated like the really high neural spines in the mid part of the tail and the long, protruding teeth of the premaxilla that are really nicely shown off here.

Buried Protoceratops



So you might be getting a bit sick of Protoceratops specimens at the moment, but this one is a bit special. Based on the first picture you can see that like some of the others, it’s nearly complete, well articulated and in good condition. The pose might look a little odd, but this is because of how it has been left to facilitate preparation. When orientated as found in the field (and as originally preserved) we see something rather more dramatic.


Yep, it looks rather like this animal was buried and tried, and failed, to get out. The formation is apparently made up of aeolian (wind deposited) sediments, so this is not something that drowned or was buried in a river channel etc., but was trapped in a sandstorm, collapsing sand dune or something similar. The head is up and the body down, implying that it survived long enough to try and make an escape but never succeeded. There are, apparently (I’ve not seen them) a number of specimens like this in other collections, and I’d love to see if there are any studies on how often this thing happens now, though I dare say it’s an incredibly hard thing to find out.

Protoceratops


I showed a collection of casts of this superb specimen the other day, and now here’s the whole thing. Preserved in a kind of sitting position, this is an amazingly complete and well-articulated specimen. The posture is unlikely to be *quite* original – the animal must have been buried while pretty fresh and obviously as the skin and muscles etc. rot the sediment will shift and settle and the limbs especially might well ‘drop’ relative the the rest of the material and help produce this ‘squatting’ posture.

This is one of the nicest specimens I’ve ever seen and has a lovely and well developed crest and jugal bosses which is great to see as well. Some nice details like the large anterior teeth and some ossified tendons are also clearly visible.



Velociraptor vs Protoceratops: part II

Dinner time! Image courtesy of Brett Booth.

Most people who have read even a little on dinosaurs at some point will have seen a photo, cast, model or reconstruction of the famous fighting dinosaurs (and if not, then follow the link to see them). However, while this fascinating fossil certainly tells us that at least one Velociraptor took on a Protoceratops this is pretty much the limit of our knowledge of their interaction from the fossil record. Protoceratops is by far the most common herbivore in the fossil record in which it is found (and of course close relativels like Magnirostris) and Velociraptor (or perhaps rather these days velociraptorines thank to thinks like Tsaagan and Linheraptor turning up) the most common predator. Although the two are quite similar in size, the abundance of both and the abundance of fossils would suggest that the two would have some sort of trophic relationship. i.e. the carnivore would be eating the herbivore in some way at some point.

Naturally one would expect a small predator like Velociraptor to target small prey (like juvenile Protoceratops perhaps) but that hardly rules out their taking the odd swipe at elderly or ill individuals or of scavenging from carcasses. If that was the case, then were is the evidence? Tantalisingly the famous CCDP (Chinese-Canadian Dinosaur Project) team reported often finding velociraptorine teeth with the bones of ornithischian dinosaurs, but without saying which ones they were, so while Protoceratops is the most obvious candidate we can’t say for sure. However, my new paper (you saw this coming, right?) describes a better association – velociraptorine teeth in association with a Protoceratops skeleton and feeding traces to boot.

I’m quite pleased with this work if only because it’s the first paper based on something I found and then wrote up which is rather nice. Credit must go to coauthors Jonah Choiniere and Mike Pittman who originally found the teeth and brought them back to camp. I had the bit of info on the CCDP report in my head and had been thinking about bite marks at the time, so after some pestering they took me to the site and together with Corwin Sullivan we started to sort through all the bone fragments to look for any with bite marks on them. Despite the intensive weathering of the bones, there were some pieces with drag marks from small teeth so we collected what we could and took it back to Beijing.

This paper reports on these finds and as noted above it consists of a couple of dromaeosaur teeth found in association with various bones with some of those bones bearing trace marks. I won’t labour the details, since it’s all in the paper, but I would like to talk about the implications here – are the fighting dinosaurs a one off, or did Velociraptor regularly go after Protoceratops.

As noted above the two animals are similar in length though of course in terms of build and body mass, the Protoceratops would have been the far bigger animal. That suggests that the dromaeosaurs would be unlikely to want to tackle something that big. Those who immediately want to leap and cite the fighting dinosaurs will hit two problems, first and most obviously, this is a single record of a single incident and it’s hard to say if it’s unique or not. Perhaps the Proto was already ill or injured, or the dromaeosaur was desperate, or who knows what. Secondly, big though the Protoceratops is in the fighting dinos pair, it’s actually probably not an adult and is only about 2/3rd adult size, so may have been a more tempting target for a predator (if obviously not a small juvenile).

Protoceratops teeth recovered at the site of our new record are pretty big and there were some fragments of big bones and over a big area suggesting these were the remains of a hefty animal. This would have been quite a challenge for a dromaeosaur to try and bring down. Even if it had, how much could it eat? The bite marks we found were on areas of bone associated with the jaws, hardly the most flesh-rich of areas, and there were multiple repeated bites. Why was this happening?

Velociraptor gets scavenging. Image courtesy of Brett Booth.

The conclusion we offer is that this is the result of scavenging. It’s unlikely a dromaeosaur could bring down such a big Protoceratops. Even if it did, there’d be tons of meat available on the legs and belly and the tail – there’s no need to go and scrape off what little lies on the jaws. Hell, even a whole group would probably get enough food from an animal that big without having to start chewing on the scraps on the face to the degree that they leave so many small marks on the bones. In short, this really looks like a dromaeosaur came across a corpse and scraped off it what it could (a meal is a meal) losing a couple of teeth and making some scrapes on the bones in the process. While this doesn’t support the idea of dromaeosaurs tacking big protoceratopsians for food, it does provide evidence that the former were probably feeding on the latter, even if that largely consisted of scavenging. Still, while such a relationship might be expected, it’s always good to find new information to support ideas and further understanding of the problems.

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Astute readers will have noted that the paper is not actually out yet. However, the journal in question released the proofs version early and the media have picked up on it. I did check with the journal and as far as they are concerned there’s no embargo on it. Since the press have already picked up on it, it would be silly for me not to mention my own research. However, please don’t ask me for a copy of the paper, I don’t have the final version yet and there are things being added to the proofs. My hand is therefore rather forced by others.

Finally a huge thank you to Brett Booth of the Carnosauria blog for producing the images above at short notice and in colour too. The artwork is Brett’s and should not be used without his permission.

Magnirostris – it’s not Protoceratops

When out at Bayan Mandahu and a few other similar localities the one thing you are bound to find is Protoceratops. This little ceratopsian is present in huge numbers and there are all kinds of fossils out there of it and lots of teeth too. It was by far the most common animal out there and it’s a reasonable bet that any unidentified scrap of bone that you find out there ultimately come from a Protoceratops.

However, to confuse matters just a little there is the extraordinarily similar Bagaceratops present and a few other taxa that may or may not be valid depending on quite whom you ask. This skull is from the putative genus Magnirostris named in 2003 but already considered likely to be a juvenile Bagaceratops. I’m certainly not in a position to delve into the taxonomy of the ceratopsians (nor do I especially want to) but it’s a really nice skull and was worth putting up.

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What is wrong with these hatchling Protoceratops?

Well I’ve got past my internet problems but a crash wiped out the new posts I had been preparing so while this will end the drought, expect only a few short ones for the next few days while I catch up. On that note, I would reiterate that I’m still looking for donated archosaur pictures for future posts.

IMG_2548So in the meantime enjoy this simple and unexciting quiz. This statue stands outside the IVPP and I walk past it several times a day going to and from the building and yet it was only after a year that a comment from Dave Unwin made me realise that there is a rather obvious mistake in the model. I’m not talking about minor anatomical tweaks like leg position or nostril size, so for any budding palaeontolgoists or developmental biologists what’s wrong here?

Continue reading ‘What is wrong with these hatchling Protoceratops?’

Terrible Lizards, series 2

A few months ago I put up a post to launch a dinosaur-centric podcast called Terrible Lizards. I and my co-presenter, Iszi lawrence, really didn’t know how popular it might be or how much momentum it would get. As such we recorded one series and then crossed our fingers.

Happily, it has been well-received and encouraged we have recorded and are already releasing episodes for the second series. The first couple of episodes are already up and we’ve kicked off with two taxa that feature regularly in the Musings in Velociraptor and Protoceratops.

All of the episodes of both series 1 and 2 are available here. It’s also available on iTunes, Spotify and all kinds of other platforms so it should be easy enough to get hold of it on your favourite website or set-up. New episodes will be coming every Wednesday for the next few weeks and there’s extra stuff available for some of our patreons too.

 

Sexual selection in dinosaurs, the story so far…

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.

 

 

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.

 

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