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.

 

Terrible Lizards – a new dinosaur podcast

With a near global lockdown and people stuck at home there’s been a rash of new podcasts forming (or at least a rash of jokes about everyone starting new podcasts while they are stuck at home) and here is the latest (and by extension, greatest) – Terrible Lizards. In my defence, I’m no stranger to podcasts and actually this one had been in the works since January and the lockdown has merely hastened its arrival rather than being its origin.

I’m no stranger to podcasts having been interviewed for loads of them at various times, but I’ve certainly never run one so this is a big step up. It is something I’d been considering for quite some time but there were various barriers to getting it going (not least time and some real expertise) when a chance meeting with an old friend suddenly made everything viable.

At a mutual friend’s Christmas party, I couldn’t help but spot the distinctive figure of Iszi Lawrence who I’d not seen in nearly 15 years so went over to say ‘hello’. Iszi was starting out as both a stand-up comedian and an undergraduate student in Bristol back while I was doing my PhD and we lived in the same block of flats. We got on well and hung out a bit and then I jetted off to Germany and we lost touch (this was before Facebook and other things like that) and as so often happens that was the end of a small friendship.

However, as also so often happens, meeting again it was like no time had passed and we were soon chatting nineteen to the dozen and catching up. She’d continued on the comedy circuit and also now runs and hosts several podcasts and radio shows (as well as writing childrens’ books and doing other stuff – find it all here) and we talked about me doing a guest spot on one of the history ones to talk about the early days of palaeontology and cover people like Mary Anning and Gideon Mantell. This though quickly morphed into doing an actual, proper, new and dedicated dinosaur podcast and so here we are.

There are of course, plenty of natural history podcasts, those on palaeontology generally, dinosaurs specifically and all kinds of others. I don’t think there’s real competition between them since it’s not like people can’t listen to them all, but it does immediately beg the question of what’s different or special about this one. I think the answer there is that we are trying to reach a truly lay audience – this isn’t a podcast that’s aimed at dinosaur geeks and nerds or students and academics, or even children – but one for people who like science but may know little more than the names Tyrannosaurs, Triceratops and Diplodocus.

We try and delve into a different subject in each episode and this is aided, in the best possible way, by Iszi’s ignorance. She can steer me to what needs to be said and explained and given context and of course her wit is there to stop me rambling on about gastralia excessively.  Her experience and expertise also means she generally knows how to host and edit one of these things so against all odds I even end up sounding vaguely professional, it’s quite a marvel. If all of the wasn’t incentive enough, we’ve managed to secure a special guest for each episode so alongside comedian Jo Caufield, Richard Herring and Alice Fraser we have historian Tom Holland, podcaster Dan Schreiber, dino-nerd and cake-maker Ralph Attanasia and legendary biologist Chris Packham to ask me some obscure, odd and downright naughty (Richard Herring, inevitably) questions about dinosaurs.

Obviously readers on here won’t normally fit our key target audience but I’d still hope it would be enjoyable to listen to and you’d learn something from it. There’s so much to talk about and explore and recover that it should be appealing no matter your existing levels of knowledge. Do though please share this to anyone who might want a listen and might enjoy it, reaching out well beyond the dino aficionados is a key part of this and you can make a huge difference with a like and share and tweet and whatever. The first two episodes are up right now here on iTunes and on here website here and we’ll be adding one a week for the next few weeks. This is something of an experiment so if we don’t get a good number of followers and subscribers this may be a short series (so consider that either a warning or a blessed relief).

Do give it a try and do give it a share. First episode? Well it could hardly be anything else, could it?

 

Gharials, dinosaurs, sexual selection, dimorphism, communication and conservation

Male (above) and female (below) gharial skulls. Photo courtesy of Larry Witmer.

So, yes, new paper time and which the concept behind this one was quite simple the outcome (as is so often the case) rather spiralled out into a bunch of other, very interesting aspects. As I noted in the run up to this post, I’ve been working a lot on sexual selection and what it means for dinosaurs in particular and wanted to use gharials as the perfect model for dinosaurs but lacked a dataset on these rare animals. A chance post by Larry Witmer led me to contact him about his dataset but it turned out to be only three animals, not the dozens I’d hoped for.

It was though, enough stimulus to get me hunting and with Jordan Mallon roped in with his interest in testing these ideas we just needed to get enough data. Happily, my former undergrad student Patrick Hennessey wanted to get engaged in some research and had time on his hands, so while I e-mailed every museum curator and croc research I could asking for photos of skulls, he set off to visit every collection in the south of the UK that was accessible. Some months later and we had an incredible set of over 100 specimens. We know of more too from photos that lacked scalebars (we were unuseable) or were in museums where we couldn’t get a response from the curator, or had various bits of skin preserved which concealed key bits of data. (We also found a good few mislabelled specimens of Tomistoma while we were at it). Still, 100 is a massive dataset for this kind of work and especially for such a rare animal and this gave us an excellent platform for our analyses.

Digging into the gharial literature though we soon found other issues. Despite the fame of these animals, their rarity means the literature on them is very small and very little is known in detail or was last written about in detail decades ago. To complicate things further, the two distinctive male traits (a fossa on the snout that correlates with the ghara, and a pair of palatal bullae) have never been truly convincingly shown to be definitively male accoutrements. Happily, an analysis of the data did suggest that the fossa was clearly a male feature and the bullae most likely were too.

Moving onto the central point of the project, analysis of the dataset showed that without pre-existing evidence for a given specimen being male or female, discovering any evidence of dimorphism was very hard, even for a dataset of over 100 animals. Gharials are strongly dimorphic in body size but the overlap between larger females and smaller males across much of the data, and the unknown sex of juveniles (which shown neither fossae nor bullae) makes finding this signal impossible. This matches what Jordan and I have said in a previous paper, and suggests that short of very large datasets and / or very strong dimorphsm (even more than seen here) or very good evidence for the sex of most specimens, it will be hard to find. That means that for the average data set we have for even well-represented species of dinosaurs (well under 100 incomplete specimens, no idea of levels of dimorphism but unlikely to be well above what we see in modern species, and no data on sex) we are not going to get a signal on dimorphism even if it’s there. I’m sure dimorphism is common in dinosaurs but I’m also sure we’re not finding it.

Female (left) and male (right) gharial snouts, the latter showing the expansion of the snout and the narial fossa anterior to the opening that makes the nares. Image courtesy of Larry Witmer.

That is, of course, based on things like body size or where a feature is expressed in both sexes (as, for example, ceratopsian fills appear to be). Presence-absence dimorphism (where one sex has a feature the other does not) should still show up relatively clearly with much smaller sets of data, but we’re not aware of any species that would obviously fit this criterion. The fossil record isn’t giving up numerous horn-less Allosaurus or dome-less Pachycephalosaurus specimens and while there are things like the two Khaan specimens with different tail anatomy, it’s just those two for now rather than a nice dataset of a dozen or so. Well-known taxa like Centrosaurus and Coelophysis are distinctly lacking in obvious dimorphism.

All of this is hopefully interesting and important for understanding sexual selection in the fossil record and as a guide for future research, but this work also threw up some interesting information for the gharials themselves which is worthy of comment. First of all, we were able to show that the fossa on the snout which is the correlate for the ghara is strongly positively allometric. This is no big surprise but it’s good confirmation that this feature is under sexual selection, and conforms with the (limited) evidence that the ghara starts growing around the time that these animals become sexually mature. We also note that it likely serves as an honest signal, since it would generate tremendous drag on the tip of the snout and that’s pretty critical for an animal with a super thin and presumably hydrodynamic set of jaws used to catch fish.

Surprisingly though, the bullae don’t show this pattern. They first appear on skulls around the same time as the fossa suggesting they are also linked to reproduction, but they first appear just before the fossa. We suggest that this is because the ghara while still small, may not need a fossa to hold it onto the skull and so the ghara and bullae may start growing at the same time, but the bullae would appear on the skeleton first. The bullae are also not allometric, so while they are larger in larger males, they are not disproportionately larger. This suggest that while they are an important part of the reproductive biology (and presumably as part of the palatal sinuses, potentially in making noise) it might be there merely to indicate sexual maturity rather than be an actual attractor. Either way, these give us some hints about the reproductive biology of these animals which gives us some hypotheses to test.

One last thing we spotted is that the very largest males are quite disproportionately robust. They have unusually wide skulls (including the normally slender snout) and also have very thick teeth, with animals only 20% smaller having teeth about half as thick. To our knowledge this has not been observed before and quite what this means isn’t certain. We hypothesise that these very large individuals might either have especially strong heads and teeth for fighting each other, or perhaps because they are entering a different niche and are able to exploit much larger prey than others. Either way, this points to an important issue given how endangered gharial populations are.

Very young gharials, yet to display any external features that might indicate their sex.

With animals under strong sexual selection, a few individual males will have a disproportionate amount of the mating opportunities in a population. But those males are also likely very well adapted to the prevailing conditions. They have, essentially, a good combination of genes allowing them to grow so big and maintain such a large ghara. If they are operating in a different niche and that isn’t taken into account (they may be eating much larger fish species compared to other gharial for example) when trying to protect them and conserve their habitats, then they might be especially vulnerable. If your genetically best adapted and fittest individuals are at most risk, that’s potentially very bad news and is unlikely to be good for the long term survival and genetic health of the population. This is of course, potentially rather speculative, but it’s supported by what we understand of strong sexual selection and the observations about the largest male skulls. It’s certainly something that is worth checking out in more detail and at the bare minimum it’s an interesting observation about their ontogeny and what that might mean for our taxonomy in the fossil record.

So here ends a very long process to analyse and assess dimorphism in gharials as a model for dinosaurs. It has thrown up far more complexity and nuance, especially in the living species themselves, than I ever thought but that has been in itself most interesting. It only remains for me to thank my coauthors for their contributions on this paper, and the huge number of curators and researchers who generously checked catalogues and sent in photos for us, the paper really would not exist with them all.

Hone, D.W.E., Mallon, J.C., Hennessey, P., & Witmer, L.M. 2020. Ontogeny of a sexually selected structure in an extant archosaur Gavialis gangeticus (Pseudosuchia: Crocodylia) with implications for sexual dimorphism in dinosaurs. Peer J.

 

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.

 

 

Interview with Brian Engh

Brian with his fighting mastodons picture

It has been quite a while since I managed to do a palaeoart interview but here is a new one with newly crowned Lazendorf prize winner Brian Engh. He is a relative newcomer to the palaeoart scene but has risen quickly and blogs extensively about his projects and thoughts on dinosaurs and has a reputation for taking on big projects with some of the more dramatic and unusual (while still biologically plausible) takes on dinosaurs and other ancient beasts.

How long have you been an artist?

As long as I can remember I have been compelled to depict things, to create characters and settings and stories, to inhabit the realm of imagination and try to manifest it in physical reality. But only recently has my truly personal creative interests coalesced in a way that I can survive off them.

Cacops attacks

How long have you been producing palaeoart?

My first commission was in 2010 for Tor Bertin’s paper reviewing the Spinosauridae. There was a big gap in paleoart commissions between that and my first truly professional paleoart commission which was the art depicting Aquilops (shown at the bottom) for the paper and press release describing that specimen in 2014.

Brian’s early spinosaur picture

What first got you interested in dinosaurs and art?

I have always been interested in unexplored worlds and strange non-human beings, and bringing those to life through art. I cannot remember a time when I did not want to look at a frog or a plant or a chicken or a bug an try to understand it. My fascination with paleontology is just a natural extension of that interest, with the added benefit of the creatures being even more alien, the worlds less explored, and both absolutely requiring art to bring them back to life.

Lazendorf prize wiining entry – Savage Ancient Seas

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

Whichever one I’m working on next. By the time I’m done with a piece I am exhausted with it and too close to it.

If I have to pick a single finished piece that I’m reasonably satisfied with it would be the life-sized portrait of “Ava” the new ceratopsian found by Triebold Paleontology that the Western Science Center commissioned. I feel like the character of a living animal is starting to come through in that piece. It was also fun to work at life-scale. There’s a strange intimacy to detailing the big snout of an animal that died 75 million years ago. It feels like grooming a big old pet. By the end of that project I really wished I could’ve seen what this individual who’s skull had been found really looked and acted like, where it hatched, how it survived, how it died and how it slept in the earth until it woke up in our modern world with a different face. I wish I could see the real animal’s face next to the one I gave it. I wonder how it would react to its own portrait…

The end of Xiphactinus

Who is your favourite palaeoartist or piece of palaeoart?

I really can’t pick because there are different ways to evaluate art & artists, and also the viewer’s mood and context is important for enjoying art. In terms of overall mood and style, my favourite paleoartist is Doug Henderson. His work “feels” right to me. It feels like the planet I know, and the prehistoric creatures inhabiting it feel like real animals you would expect to find living in this ancient planet. But Doug isn’t really active any more, and it seems that the difficulty of making any decent money off of paleoart and the other frustrations that come from interacting with the paleontological community seem to have worn him down and made him throw in the towel on paleoart, so I can’t say he’s my favourite artist in terms of his career. John Sibbick’s work is also gorgeous, viscerally compelling, often amazingly believable-looking, and it was hugely influential on me as a kid. I would say his animal reconstructions are my favourite in terms of the character or attitude they exude, and his plant reconstructions are the most texturally satisfying I’ve ever seen. Unfortunately he also has become much less active in paleoart since the 90s, but I really don’t know anything about him or his career beyond that. I also love James Gurney’s work, but more for the fantasy side of what he does. Gurney’s work makes me feel like life will persist and is good. There’s a sentimentality to his work that seems almost restorative for the mind and soul. It is also to his credit that he his still active in both the publishing and scientific worlds, and he shares his knowledge through his youtube page and blog. I admire all of that a lot. Mark Hallett is also at that rare intersection of still being active as a professional artist and having tremendous skill and an amazing body of work. I had the good fortune to meet him at SVP in Salt Lake in 2016. I didn’t realize until I met him that Mark was born with one arm. Despite this handicap he has developed top-level skills in drawing and painting, and has executed some of the most ambitious and beautiful pieces of paleoart anyone has ever pulled off. On top of all that he doesn’t seem to have let the often petty, political and poorly funded world of paleontology jade him too much. He has continued against all odds to grind through making paleoart, and in 2016 he released a huge book on sauropods with my friend and long-time collaborator Matt Wedel. You should probably include a link to where people can buy that here (ed: done!).

Feeding sauropods

What is your favourite dinosaur / archosaur?

I don’t have one, but because kids at outreach events ask me this all the time my go to answer is cassowary… because then I get to tell them about how goddamn awesome cassowaries are and that dinosaurs never fully went extinct.

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

Yes of course. All of the ones I have not.

Hypothetical inflated throat sacs for large sauropods

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

Inspiring wonder and awe.

In recent years obnoxious know-it-alls mostly on the internet have steered every conversation about paleontological art toward evaluating its “scientific accuracy” despite the fact that these self-made experts are pedeantic dickheads that only remember laundry lists of facts so that they can look smarter than people, rather than actually developing a solid grounding in biology by which to have any real discussions. I think this has caused a significant beating back of the creativity of a lot of artists interested in paleontology, and has contributed significantly to a lot of really beige, conservative paleoart in recent years, despite all the amazing discoveries published every other day it seems. These same paleontological pests are the same people who will look back on a piece by Knight or Burian or the sculptures at the Crystal Palace and mock them for being “tail dragging lizards” and “totally incorrect,” and in doing so completely fail to recognize that this art inspired generations of subsequent artists and scientists to take an interest in natural history. Although antiquated, these past works had that effect because they were aesthetically beautiful, impressive, and gave people a window to a world that they had never seen or thought about prior to encountering that art. At best a piece of paleoart can only reflect some of the current views and knowledge on a given paleontological subject, and as more fossils and discoveries come to light nearly ALL paleoart will eventually be totally inaccurate. We should actually hope for this, because it means science and our understanding of our planet is advancing, and we shouldn’t view older art as “bad” because it is no longer up-to-date. For this reason I am fully willing to take the risk of having my work labeled “too speculative” or “sensationalized”, and it’s part of the motivation for hosting my own paleoart contest, where the main criteria I’ll be judging and rewarding the work on is creativity and originality. The contest ends November 1st, and I am excited by all the wild entries I’ve received thus far. I hope that any artists out there who haven’t entered will do so before the deadline! You can learn more here.

Cryptic Aquilops

As ever all images are copyright to Brian and are on generous loan here. Please speak to him if you want to use them.

 

Testing for sexual selection

I had a new paper out a few weeks ago but it was at the very height of my busy start to teaching and so barely even got a tweet out about it and completely failed to do anything on here. That’s a shame as this is a paper that has some serious and major implications for trying to detect sexually selected structures in extinct animals (and indeed looking at some odd structures in living ones too). I’ve written a huge amount about dinosaur dimorphism and sexual selection and with numerous papers covering different aspects of the evolution and behviour of dinosaurs (and pterosaus) when it comes to signals and sexually selected things like crests, spines and horns.

The short version is that these are of course hard to look at becuase we can’t directly observe behaviour in extinct animals and coupled with small sample sizes, taxonomic uncertainty of specimens and then issues like extended growth periods and cryptic dimorphism and this is a frustratingly tricky subject to tackle. One standard, if imperfect, measure has been to look at the growth trajectory of the anatomical feature in question and to see if it grows more rapidly than the rest of the naimal, especially iof this happens relatively late in ontogeny. In short, animals don’t need sexaul display structures when they are not sexually mature but when they are this is important so things like horns tend to be small for a long time and then grow very quickly.

This paper led by Devin O’Brien and featuring a host of sexaul selection theroists and biologists posits that things may be more complex still. Features that directly rate to body size will be postively allometric (this can include things like horns and crests in dinosaurs) but those that are not (like say a moths’ antenna), will not. The former are accurate representations of the animals they are attached to and so act as a proxy for their size and quality, but other traits that can still be variable and under sexual selection are not acting in this way and so wouldn’t follow this pattern. There may even be some allometry in these latter traits (non-reproducing animals will not likely invest in such features until the can mate) but the allometry will be much greater, and the correlation with body size present in visual signals.

To help resolve this, we also reccommend in the paper that allometry be tested not jsut again body size but also some other reference trait that is likely to (or been shown to) grow close to isometry. So for example, don’t just measure your dinosaur horn as it related to overall skull size, but also compre it to something like tooth size or humerus lenght. That will help keep things clear when there are other traits around that can grow rapidly or are large but that don’t function as signals. One wonderful example of this we inlcude is a comparisons of the horns on the head of a chameleon with the lenght of the tongue. We used foot size as a reference trait andf show that while both tongues and horns do show allometry, the tongue is little more than isometric but the horns (used in combat and an obvious visual siganl to reflect that) have a much greater allometric slope and show greater variability which is likely to reflect differing quality.

We include a whole raft of such measures of various animals from insects up to mammals and covering both signal and non-signal traits. Two extinct animals were included based on dataset I’ve been working on for a while and may be of interest. One was the frills of Protoceratops which I and colleagues did some time ago but now updated with some extra specimens that we did now have before. These produced a simialr result to our analysis which is no big surprise but nice to see the previous results verified. The second one though was to look at the growth of the tail vane in Rhamphorhynchus.

The standard interpretation of basal pterosaur tail vanes has been that these functioned in steering in flight and acted as something of rudder. That works out quite well since many of the shapes adopted are surprisingly close to the rudders actually made for various aircraft and putting a small vane at the end of the tail would make mechanical sense to increase the effects. However, it is notable that the vanes for Rhamphorhynchus (the only pterosaur where we have a decent sample size) seem to change quite dramatically in shape as they grow and this is rather at odds with the idea that this is purely mechanical. Similarly, there is some serious variation between various basal pterosaurs in vane shape which suggests that the tail is unlikely o be (purely) mechanical in function and the fact that the pterodactloids gfot rid of theirs implies it is hardly critical for flight. Some people have suggested that these vanes were therefor acting as some form of signal and our analysis bears this out. The height of the vane grown very considerably and shows strong positive allometry as the vane changes from a narrow leaf shape in juveniles to a triangle in adults. The vane could of course be multi-functional and it could well be that it has been co-opted from something initially mechanical to function in signaling.

The fundamentals of the methods and theory described here have been around for some time, but the nuance is important to try and distinctuish between traits that are sexually selected and those which are also likely used in some form of display and even combat. It should make for a more reliable way of assessing these kinds of traits and that should be of real benefit to palaeontologists who have an interest in these things. I hope it is not long until more animals are formally assessed for their growth trajectories and what that might mean for understanding their behaviour.

The paper is open access and is freely avaiable here:

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.

Ceratopsian horns and frills – what drove their evolution?

So I have another new paper out on sexual selection and what this means for dinosaurs. This one has been led by my PhD student Andy Knapp (follow him on Twitter here) and he agreed to write about it here:

Ceratopsians are among the most instantly recognisable dinosaurs thanks to their enormous, elaborately-adorned skulls. The frills and horns of ceratopsians have been the subject or ongoing debate in palaeontological circles since the discovery of Triceratops in the late 19^th century. Triceratops is known to everyone, specialists and non-specialists alike, and remains the classic example of ceratopsian skull morphology, with three large forward-pointing horns and a thick, shield-like frill extending back from the rear of the skull. It seemed obvious to early palaeontologists that these features had evolved for protection. The trouble is that Triceratops is almost alone in possessing this precise combination of features. Many of the larger ceratopsians that we know of didn’t have such large horns, and most had large, weight-saving fenestrae in their frills which would offer little protective value in life. In recent years the large number of known ceratopsian species has increased with a steady stream of new discoveries, each with its own characteristic horn and frill morphologies. These discoveries have posed a whole load of new questions as to what their purpose was.

Large, elaborate features with no obvious use – such as the frills and horns seen in ceratopsians – are expensive to grow and maintain, and obvious parallels in living creatures involve sexually selected features. The most extravagant examples of sexually selected features, as realised by Darwin in his book The Descent of Man, involve extreme sexually dimorphism in traits and/or overall size; peacock tails, elephant seals, etc. In contrast, there is no convincing evidence of sexual dimorphism in any ceratopsian taxa. This has led some researchers to reject the hypothesis of sexual selection as an explanation for exaggerated features in ceratopsians and other dinosaurs, and suggest that instead these features have evolved for species recognition.

Species recognition is the idea that being able to differentiate members of your own species is vital in herding, protection and mating. Basic examples of ‘species recognition’ are everywhere in nature; zebras don’t have trouble telling lions apart from other zebras! The more specific idea that physical traits evolve as a mechanism to allow differentiation is controversial. There are a few known examples of divergence of traits in closely-related taxa where hybridisation could be detrimental to fitness, a process known as reproductive character displacement. This is distinct from ecological character displacement, where sympatric taxa that fill similar ecological niches diverge in traits associated with resource acquisition. The rock nuthatches Sitta neumayer and S. tephronota exist across central Asia in partially overlapping ranges. Where they are sympatric, the distinctive dark eye stripe, ubiquitous across the rest of the two species’ ranges, fades in intensity in the population of S. neumayer. This has been interpreted as an adaptation to prevent hybridisation between the two species. Crucially, other known examples of reproductive character displacement involve minor modifications to pre-existing, often sexually selected features.

Reproductive character displacement is not expected to operate where a taxon exists in isolation, because there is no evolutionary pressure for traits to diverge. This prediction allows us to test the hypothesis of species recognition as an explanation for the presence of distinctive traits in extinct taxa for which we have good geographical information. Ceratopsians fit these criteria well. They were widespread across North America and Asia, speciose, and many species are known from relatively complete remains. We compiled and assessed a list of 350 cladistic character traits for a 46 well-known ceratopsian species and compared how the traits generally considered ornamental, and thus contenders to be species recognition traits, varied between sympatric and non-sympatric species. We also examined at other traits; those that were internal and therefore not visible during the animal’s life, and those that were external but not considered to function as a display trait. We then conducted a pairwise comparison of each possible species pair for three distinct character classes; internal, display, and external non-display.

We then compared the results for species pairs known to be sympatric and, therefore, likely to encounter one another in life, with non-sympatric species pairs. For each category we found increasing character divergence with increasing phylogenetic distance as expected, but, crucially, found no difference between the disparity of the display characters of sympatric species and those of non-sympatric species. This suggests that interaction between species has no effect on the evolution of ornaments in ceratopsians, and that species recognition is not a contributing factor to ornament evolution. Of course, it is entirely plausible that ceratopsians were able to identify conspecifics by their ornamentation, but this would have been a byproduct of ornamentation, not a cause.

The ruling out of species recognition as a driver of ornament evolution, at least in ceratopsians, shortens the list of possible explanations. Avoiding hybridisation would benefit both parties and so the evolution of distinguishing features should tend towards a zero-cost exercise. In contrast, ceratopsian skulls are the largest of any terrestrial vertebrate and impose certain limitations on their bearers. Computer models of ceratopsians have shown their massive skulls shifted their centre of mass further forwards than other quadrupedal dinosaurs. Compared with the hadrosaurs that they shared the ancient river deltas of what is now Canada’s Dinosaur Provincial Park, this made them poor swimmers and liable to drown when crossing bodies of water. This obvious handicap, along with the sheer cost of growing and maintaining such a large component of overall body mass that has no obvious mechanical or ecological function, points to an explanation that favours investment in high-cost structures.

An additional result of our analysis was that at the lowest phylogenetic distances, ornamental traits were around ten times more diverse than internal traits and three times more diverse than non-ornamental external characters. This suggests a general trend for rapid evolution of ornamental traits. Rapid evolution and high-cost are both hallmarks of sexually selected features. If the frills and horns of ceratopsians are sexually selected, as has been previously suggested, they are distinct from extant taxa in being both highly exaggerated and sexually monomorphic. This combination suggests strong sexual selection that applies more-or-less equally to both sexes. Some evidence for ceratopsian ornamentation being sexually selected has been demonstrated previously, and this study both adds to this evidence and rejects a competing hypothesis. Ultimately, our findings open up further avenues for exploring the life history and ecology of these fascinating and enigmatic creatures.

 

Knapp A, Knell RJ, Farke AA, Loewen MA and Hone DWE (2018). Patterns of divergence in the morphology of ceratopsian dinosaurs: sympatry is not a driver of ornament evolution. Proc. R. Soc. B. 20180312. http://dx.doi.org/10.1098/rspb.2018.0312

 

References

Brown WL and Wilson EO (1956) Character displacement. Systematic Zoology. 5: 49-64

Darwin, C. (1871). The Descent of Man and Selection in Relation to Sex. London, John Murray

Henderson DM (2014). Duck Soup: The floating fates of hadrosaurs and ceratopsians at Dinosaur Provincial Park, in Eberth D and Evans D (eds). Hadrosaurs. Bloomington: Indiana University Press. pp. 459-466

Hone, D.W.E., Wood, D., and Knell, R.J. (2016). Positive allometry for exaggerated structures in the ceratopsian dinosaur Protoceratops andrewsi supports socio-sexual signalling. Palaeontologica Electronica. 19.1.5A: 1-13

Knell RJ, Naish D, Tompkins JL, and Hone DWE (2012). Sexual selection in prehistoric animals: detection and implications. Trends in Ecology and Evolution. 28; 38 – 47

Maidment SCR, Henderson DM, and Barret PM (2014). What drove reversions to quadrupedality in ornithischian dinosaurs? Testing hypotheses using centre of mass modelling. Naturwissenschaften. 101: 989 – 1001

Padian, K. and Horner, J.R. (2010). The evolution of ‘bizarre structures’ in dinosaurs: biomechanics, sexual selection, social selection or species recognition? Journal of Zoology. 283; 3 – 17

Buried Treasure – Matt Wedel

I’m not quite sure whether I’m supposed to be talking about my favorite paper out of my little flock, or the one that I wish had gotten more attention. But it’s okay, because the answer in both cases is the same: my 2012 paper on long nerves in sauropod dinosaurs. It’s freely online through Acta Palaeontologica Polonica.

This one is my favorite for several reasons. I think it’s the most personal of my papers, in that there was no obvious need for it, and probably no-one else was ever going to write it. Whereas with pneumaticity I just got in at the right time – that work was going to be done by someone, and probably sooner rather than later. I also like the long nerve paper because all it required was thinking. I didn’t discover anything, and I didn’t do any real work. In fact, at the outset I was basically thinking of it as sort of a stunt paper. If it had any broader meaning at first, it was merely, “Ha ha, I thought of this before anyone else did.”

But that’s the great thing about science – if you pick up any given thread and follow it, you may soon find yourself in a labyrinth of possibilities, like Theseus and Ariadne in reverse. That happened with the sauropod nerve project, which has spun off in a couple of new directions for me. One is thinking more about the peripheral nervous systems of extinct animals, which has attracted almost zero attention so far. It’s pretty esoteric – nerves leave even less of a trace on the skeleton than air sacs – but there are some interesting and useful inferences that we can draw (to find out what those are, wait for the paper!). The second spin-off is that writing the 2012 paper fired my interest in the physiology of neurons, and in fact kicked off some conversations and potential collaborations with neuroscientists. That is a career wrinkle I never anticipated.

Still, I have to admit that it is a paper without a lot of obvious applications. It hasn’t been cited much – about half as many times as other papers of mine from around that time – but I have been happy to see it cited in a variety of fields, including neuroscience, computer science, and linguistics. That’s satisfying because I cited works from a variety fields in writing the paper in the first place. In part that was because cell biology in giant dinosaurs is an inherently cross-disciplinary problem, and in part because the example of the recurrent laryngeal nerve in the giraffe has become widely known and referenced across so many fields.

My goal now is to build on the 2012 paper with at least a couple of follow-ups to show paleontologists that, yes, there is some actual science to be done here, beyond the gee-whiz aspects. That was the subject of my talk at SVPCA last year. And as I said at the end of that talk, if you’re interested in the interplay of evolutionary novelty and developmental constraint across multiple levels of biological organization, thinking about the cell physiology and comparative anatomy of large animals is a fertile playground.

The Tyrannosaur Chronicles is here!

Well it’s been coming of course but today sees the publication of my first book. I’ve always wanted to write one and now it’s done and I can (sort of) relax. There’s lots of PR stuff ahead and the official book launch tomorrow, but there’s not much to do now except let it go free and hope that most people enjoy it.

I’ve been writing about dinosaurs and palaeo one way or another for nearly 10 years now between various blogs and ventures as well as the odd review paper and book chapter that are for more of a general audience than a typical paper, but this is obviously a much bigger and rather different undertaking. It’s also rather different in that I was writing for something of a different audience (certainly compared to here where I generally assume readers know at least a little anatomy, what a phylogeny is, what the main time periods were etc.) and over a long book you want to introduce quite a few topics and aspects of not just tyrannosaurs, but also their contemporaries and major issues like behaviour, anatomy, local environments, extinction and more. It turned out to be a lot to cover and while trying to keep it interesting for the reader.

Hopefully, I’ve managed that but it is nervy letting this out into the wider world with little control over it. That may sound odd given how much I’ve written online, but with a blog (either here, on Pterosaur.net or on the Guardian) you have a fair idea of who your audience is likely to be, and people will soon leave if they don’t like it. Getting someone to pick up and be immediately drawn to, and then stick with, a whole tome is rather different so obviously I am nervous and curious as to how it goes from here.

The book is very much in the popular science mould and so while I would hope even some academics and researchers would get something from it and enjoy it, really it is aimed squarely at the general public and those with little or no knowledge of dinosaurs or paleontology and even biology in general. As a result, despite the fact that the book is around 85 000 words long, it really doesn’t delve into the tiny details of but tries to cover a broad spectrum of tyrannosaur origins, evolution and their biology. Given my interests there’s quite a lot on ecology and behaviour and there’s a few bits of informed speculation or suggestions that I hope are novel and interesting, but also clearly flagged as such.

It was a huge effort to write all of this while keeping up with a full time academic job and try and keep my other blogs ticking over, and it was also important to try and update things. The last few years have seen a near endless stream of new tyrannosaurs being named and some parts of the book I changed a half dozen times to reflect the addition of new species, and with the book going to print in February, it’s inevitably already out of date thanks to the most recent addition to the ranks of this clade, despite my efforts. Still, I have tried to make this a modern take on tyrannosaurs and I hope I have managed to overcome a few of the more persistent anachronisms and misconceptions about these animals. Anyway, enough of the (brilliant) text and its (brilliant) author, and time to talk about some other aspects of the book and to give a minimal amount of credit to other people.

The book is illustrated by Scott Hartman and there’s around a dozen figures of his scattered through the book, with lots of skeletals (especially of tyrannosaurs, but also various other dinosaurs too) and other little bits, a number of which were done especially for the book, but will be popping up on his website if they haven’t already. I’m obviously especially grateful to Scott for finding the time to do these and putting so much time and effort into them, the book benefits enormously from it.

There is also a colour section in the middle with numerous photos of various specimens and some reconstructions. Plenty of these have been in print in various places before but there are some novel shots and views of various things and I’ve been blessed with the generous assistance of numerous colleagues and friends who have sent in pictures and allowed me to use them. While I’m on the subject therefore I must thank Peter Falkingham, Jordan Mallon, Larry Witmer, Xu Xing, Lu Junchang and Phil Currie for providing various images and also the Royal Tyrrell, LACM, IVPP, Hayashibara, Mongolia Palaeontological, Royal Sasketchewan, Carnegie and New Mexico Museums, and also Don Brinkman, Mark Loewen and Matt Lamanna for helping me negotiate to get a couple of the images. Finally I must also thank Darren Tanke and Chisaka Sakata for the photos of me that are on the covers of the paper- and hardbacks respectively.

Finally with regard to the text I had a series of editors and assistants at Bloomsbury though most especially I want to thank Jim Martin for commissioning the damned thing in the first place and also in particular for supporting my campaign for the colour scheme of the cover. Several friends of mine including Marc Vincent (yes, that one) read through an early draft for me and provided useful feedback and special mention goes to Tom Holtz for reading through it looking for errors (and mercifully he found only one, so I’m happy to blame him for any others that slipped through). A whole host of other friends, collaborators, coauthors and colleagues are thanked in the acknowledgements for sharing their knowledge of tyrannosaurs with me over the years and I hope this book helps do justice to these amazing animals.

Well, the book is out now (actually I’ve had reports of it being on sale since Monday) and while I’ve always wanted to say it’s available in all good bookshops actually I have no idea. It is available online (including direct from the publishers Bloomsbury) and it’s in at least a few physical places. I know it’s available in hardback (paperback coming next year) and e-book versions and there’s an audio version coming via Audible, and hopefully a few translations too. The US have to wait till early June, but not long for you to wait and in the meantime you can enjoy me talking about the book here. Hopefully many people will find it one way or another (such as in charity shops for £2 in a few weeks) but more importantly I do hope people enjoy it. Happy reading.

Dinosaurs Monster Families

Even people living in London may not know the Horniman Museum which sits in south east London, just a few miles from the famous Crystal Palace dinosaurs. The Horniman is a small museum with an excelletn and old-fashioned natural history section full of bones and taxidermied material but with some great illustrations of development, variation and evolution. There’s a section on human cultures and especially tribal artefacts, a small aquarium in the basement and  a petting zoo and gardens. It’s well worth a visit anytime, but they also regularly have special exhibitions and right now it is the above titled one on dinosaur eggs, nests and babies.

 

The exhibition is not large but it is excellent. I’ve only included a few snapshots here but hopefully it’s clear that there’s some wonderful specimens (almost all casts, but very few are of specimens or even species I have seen before and none will be well known in the UK), with interesting mounts, excellently presented information and lots of detail. There are some looped videos of researchers talking about major discoveries like the brooding oviraptorosaurs and also lots of top Luis Rey artwork. Luis was actually integral to the origin of this traveling exhibit (it’s also been in Spain and Italy but I don’t know where it’s headed next) and hence the liberal splashing of his works.

 

Given the theme it’s perhaps no surprise that most of the material is based on Mongolian and northern Chinese specimens – Protoceratops and oviraptorosaurs feature heavily as does Tarbosaurus and innumerable eggs and nests. Again though, while this might in one respect be a bit same-y, you’d have to pay close attention to notice and it’s not played as a central point, merely that so much accessible material is from there so it features. Still there’s stuff from Argentina and North America and lots of key sites and specimens get a mention.

In a nice touch, the last case is a collection of modern specimens from the Horniman’s own collections showing off various bird and their eggs and some other goodies. There’s also a very special ‘guest’ that is quite remarkable to see but I won’t spoil the surprise for anyone going.

The museum also has an excellent record of using these temporary exhibits to carry out additional activities and outreach events, bringing in artists and experts to talk about them to various groups and creating extra activities and presentations. Somewhat inevitably therefore I got roped into this and in the opening week look along a gang of students and colleagues to talk dinosaurs and their biology and evolution and I’m back again in a couple of weeks for another talk.

Overall this is a superb little exhibit, there’s a lot to see, it’s well laid out and there’s some interesting and exciting specimens. It’s well labeled and there’s a lot of information to potentially digest and I can highly recommend it.

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.

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.

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.

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.

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.