Elaphrosaurus last got a mention here way back in 2009 when Limusaurus came out. In the phylogeny accompanying that paper, the two were recovered as sister taxa which hinted at the possibility that Elaphrosaurus was also herbivorous. Given that there’s no known skull, that’s not as outrageous as it sounds alongside this image – the head was reconstructed before Limusaurus was known. Whichever way it cuts though, this is a great specimen in great condition and a lovely mount that shows off the material. You can also spot a really quite hefty theropod femur in the case behind it as well – this might be the only vaguely-complete theropod from Tendaguru, but it’s far from the only theropod known.
Archive for the 'Dinosaurs' Category
I’m badly behind on the blogging here and especially covering my January trip to Berlin owing to a combination of illness, work and the Daspletosaurus project (only 3 weeks left!). Still, while there’s much more to come, I’ll grab a few minutes and post a little about the big bone store in the basement in Berlin featuring these wonderful containers (if you don’t know what they are, feel free to guess, answer at the bottom below the fold).
As briefly mentioned before, I’m just back from a week long trip to Berlin and the Museum fur Naturkunde (better, but now incorrectly known as the Humboldt museum). The last time I was there was around 2007 and the main dinosaur hall was empty with the material having been taken apart for remounting. So while I was there to dig into the collections and check out the material available, it was a chance to see how the new exhibits (plenty more than the dinosaurs have been done) look. I’ll stretch it out a little and break this up into various small slots covering different aspects of the exhibits and first off let’s not sidestep the obvious – they have a full sized, mostly real bone, mounted Giraffatitan. Yes this is a far from tiny mount, it’s absolutely colossal and that’s most apparent when you see that it’s next to Diplodocus (also shown at the top) – the sauropod that most people have probably seen in a museum and are most familiar with. Giraffatitan simply *towers* over this and in every dimension except total length is clearly a much, much larger animal.
The remounting here gives both of these animals a more ‘modern’ look and less tail-draggy and generally upright. One really nice addition is the cervical ribs being added to the G. mount, giving it a much more accurate neck and showing off this often missing (or badly handled) feature of sauropod necks. The third in the sauropod trio is the fascinating and short-necked Dicraeosaurus. Indeed, between the three, you have a really classic in Diplodocus, a real giant in Giraffatitan (and a very upright one to boot), and then a relatively small and short-necked animal in Dicraeosaurus. This guy does have a short neck, but look at the height on the cervical nerual spines and that lovely bifurcation into pairs of spines.
And finally as a little bonus, I took this one as it looked like a nice novel view, but on reviewing it in hindsight, it’s clearly in ‘Luis-Rey-O-Scope‘.
I’m just back from a quick visit to Berlin and so once I’ve caught up with all the usual stuff that gets behind from being away there’ll be some blogs coming on the exhibitions, Berlin Tier Park and others. Meantime though, here’s the Berlin Archaeopteryx. I have seen this magnificent and legendary specimen a couple of times before and have some old analogue photos, but now have some nice shiny digital ones to put up here. Oddly this is the one obvious specimen that’s been missing from my ‘collection‘. It has been on here before thanks to Heinrich Mallison, but now I can add my own shots to flesh this out with a couple more.
Today Scott Persons returns to the Musings to talk more about theropod tails, their musculature and possible uses. This time around, it’s the oviraptorosaurs:
Previously on Archosaur Musings . . .
After my first post on dinosaur tails (which was mostly focused on the rear-ends of tyrannosaurs), I was asked a seemingly innocent question in the comments section by archo muser “Lucy”. She wrote:
“So what about oviraptorids and their reduced tails – do we assume they went the same way as emus? And do we know anything about the other maniraptors (I’m particularly thinking of dromaeosaurs and their famously odd tail design)?”
I suspect no malice on the part of Lucy and her question, but her inquiry had inadvertently put me in a corner. She had asked a good question . . . so good that I had already devoted two chapters in my master’s thesis to thinking about it and had two papers addressing the question in the works. So, I had the wherewithal to answer it, and that was my dilemma.
I am of the opinion that science should not be a covert affair. New scientific discoveries should not be closely guarded secrets. By its very nature, science benefits from transparency and from the unobstructed flow of ideas. And yet, in the modern system of journal-based publish-or-perish scientific academia, a certain level of discretion and intrigue is prudent.
Otherwise, you might get scooped. You might prematurely tell one too many colleagues what you are researching and what your results are, and, next thing you know, those ideas wind up in someone else’s publication. Maybe that someone else was already thinking the same thing and, upon hearing that they are not the only one following that particular line of thought, they rush to publish first. That leaves you with an outdated thesis and nothing new to report (and the best academic journals don’t do reruns). Consider, as an extreme example, what Alfred Russel Wallace’s place in the history books would be if he had kept his ideas to himself until going to print and hadn’t sent a certain letter to a certain long-bearded British naturalist. And sometimes, of course, the scooping can be downright nefarious.
Not that dino tail research is a ticket into the history books (I am just happy when I get asked to do a guest blog), but what seems like your own quiet little corner of paleo research can get scooped out from under you. It has happened to some of my friends. So, I did not want to tip my hand and give Lucy the answer that her question deserved. Instead, with all the aggravating crypticness of a magic eight ball, I gave what I’m sure was a dissatisfactory answer. I said, in effect, “Why, yes, dromaeosaurid and oviraptorids do have unusual tails, and, yes, I do think they were specialized for unusual functions. I am going to publishing on those topics soon. Ask again later.”
Both raptor tail papers have come to academic fruition, and I am now free of my research paranoia. The paper on dromaeosaurids (coauthored with my graduate supervisor Dr. Phil Currie) has been published in a special volume of Acta Geologica Sinica, and the paper examining oviraptorid tails (coauthored with Dr. Phil Currie and Dr. Mark Norell) is now available for early view in Acta Palaeontologica Plonica. If you are interested in what I think was going on with dromaeosaurid tails (and I think a lot was going on), then you can checkout the guest post that Dave asked me to do over at Pterosaur.net. That leaves us with the tails of oviraptors . . .
“Do we assume they went the same way as emus?”
Oviraptors have short tails (both in terms of the total number of vertebrae in their tails and in terms of tail length relative to body length). It has been argued that such short tails are evidence that the group did go the way of the emu — i.e., the ancestors of oviraptors had reduced tails for the purpose of flight and that this reduced-tail condition was retained after the group had become secondarily flightless. In fact, it has been argued by various scientists that many groups of fully-terrestrial dinosaurs may have descended from flight-capable ancestors. It is my opinion (though many wise and respectable scientists would disagree) that some of these arguments for secondarily-flightless dinosaurs are probably valid. However, in the case of oviraptors, I don’t think that the tail lends much support to the secondarily flightless hypothesis. Let me tell you why.
Those readers who made it through my first tail post will recall that I am interested in the musculature of dinosaur tails (as inferred through digital reconstructions based on skeletal attachment sites and comparative dissections of modern animals). In particular, I am interested in the caudofemoral tail muscles. Caudofemoral muscles are part of the locomotive system. They attach via tendon to the femur, and their retractions helped to propel a dinosaur forwards when walking and running.
In birds, the caudofemoral muscles are tremendously reduced and sometimes completely absent. That makes sense. To fly, a bird benefits from weight reduction, and what better weight could a bird reduce than that of a big muscle dangling off the rear that functions in land-based locomotion. Emu’s have reduced caudofemoral muscles (they compensate for this, as many birds do, by placing less emphasis on femoral retraction when they walk and run), but there is every indication that oviraptors did not have reduced caudofemoral muscles.
Readers of my past post may also recall that caudofemoral muscles do not extend too far back towards the tip of the tail. Instead, most of their mass is located near the tail base (by the hips and legs). The shortening of oviraptor tails appears to have been restricted to the post-caudofemoral region of the tail – that is, vertebrae near the tip were lost — and I found no evidence that the caudofemoral muscles of oviraptors were reduced. Oviraptor tails were shortened, but not at the expense of muscles that helped them to move on the ground. Not like an emu.
Curiouser and Curiouser
What about the other tail muscles, are they reduced? Yes, and no. The other muscles of an oviraptor tail are considerably reduced in relative length, but not in relative mass. Wide caudal ribs (transverse processes), among other features of the tail skeleton, affirm that oviraptors had unusually robust tail muscles. Oviraptor tails were short, but stocky.
In an oviraptor tail, the individual vertebrae were short and the vertebral articulations suggest a high degree of flexibility in between the vertebrae. So, oviraptors had a lot of flexor points crammed into their short stocky tails. Per unit of tail length, an oviraptor tail may have rivaled all other theropods in its flexibility.
Then, we come to the very tip of the tail, and that’s when things really get strange. Back in 2000, it was announced that the oviraptor Nomingia had a tail that terminated in a series of fused vertebrae. This fused terminal tip was termed a “pygostyle”. Pygostyles are found in the tails of modern birds and are thought to be associated with anchoring a bird’s fanning tail-feathers. Did Nomingia have a tail feather fan? It seems likely. Direct proof that some early oviraptors had tail-feather fans comes from exquisitely preserved specimens of Caudipteryx and Similicaudipteryx, which actually have fossilized feathers preserved.
In our oviraptor tail paper, my coauthors and I announced the discovery of three new oviraptor pygostyles. One of these was from a second specimen of Nomingia, one was from Citipati, and one (the smallest of the three) was from Conchoraptor. These new pygostyles suggest that Nomingia may have been the rule, not the exception, and that pygostyles along with their accompanying feather fans were probably common features of oviraptors.
If You’ve Got It, Flaunt It
Muscular, flexible, and ending in a feathered flourish, what were oviraptor tails doing? I think they were flirting.
What good are tail feathers if you cannot fly? A lot of modern birds make use of tail-feather fans when they are on the ground. Think about a tom turkey or a peacock. Such birds use flamboyant feather-fans as display structures, most commonly, as courtship display structures. Now, imagine if the avian ancestors of peafowl and turkeys had not been forced to abandon the longer and muscular dinosaurian tail for the sake of aeronautics. What sort of a tail might these birds “want” in order to best woo potential mates and to wield their feathery instruments of seduction? Flexible, strong, and muscularly dexterous tails.
Lucy, I want you to know that this follow-up blog post was unsolicited. I trust that Dave humors me and posts it, and I hope you are satisfied with the answer. Sorry for the delay.
Tags: claws, Dinosaurs, ecology
In the last couple of weeks I’ve had two papers come out in PLoS ONE tackling different aspects of dinosaur ecology. In rather different ways both look at the morphology of various living clades and use that to build up an idea of what patterns are present and how dinosaurs fit into this.
The Musings is set more or less to idle these days, so I don’t want to say anything too extensive here, not least when I have blogged the most recent paper already on the Lost Worlds and Darren Naish has some very extensive coverage of the first one. Still, I don’t want this one to dry up entirely and with a dinosaur-keen audience, it seemed a good idea to get up at least a quick post on the two.
First off there’s a paper on claw shape and how this might, or might not, relate to possible climbing functions. The major results are somewhat equivocal. Perhaps unsurprisingly, there is a lot of variation in claw shape (curvature and midpoint dorsoventral height) and that means the boundaries are blurred between those animals that climb from those that are predatory or based on the ground. In short, for most it’s hard to make any kind of confident predictions off of our analysis at least, but there is a lot of scope for further work, and at least some dinosaurs plot out clearly in one behavioural category and well away from the others.
Second, there’s the piece on dinosaur body size distribution. Here non-avian dinosaurs are shown to have a different pattern of body size distribution to various vertebrate clades both living and extinct, with dinosaurs having relatively few small species and a high number of large ones. This nicely fits with the idea that dinosaurs filled multiple niches as part of their ontogeny, with niches for small species being filled by juveniles.
I’ll keep it short and sweet with both being freely available to read as obviously all the details are in there.
Birn-Jeffery, A.V., Miller, C., Naish, D., Rayfield, E.J. & Hone, D.W.E. 2012. Pedal claw curvature in birds, lizards and Mesozoic dinosaurs – complicated categories and compensating for mass-specific and phylogenetic control. PLoS ONE, 7: e50555, 11p.
Tags: evolution, fossils, palaeontology, review, sexual selection
Regular readers will know that for the last few years I’ve been slowly building a research profile concentrating on the behaviour and ecology of dinosaurs and pterosaurs. While the various papers on feeding behaviour, stomach contents, predation and niche partitioning in theropods has been the more high profile, I think the work on sexual selection is arguably more important as it potentially has profound implications for how we interpret all manner of fossils and how they may (or may not) relate to one another. After all, there’s a major ecological and taxonomic difference between identifying two species of a clade, and one species that exhibits major sexual dimorphism.
My colleagues and I have already looked at the idea that sauropod necks were driven by sexual selection, and after much strife, finally got a paper published discussing mutual sexual selection and the implications that has for diagnosing taxa in the fossil record and what it might mean for parental care and other aspects of behaviour. There’s more to come in these areas as I have further work planned and am involved in some other areas linked to this, so the area is growing rapidly and, I hope, ripe for a general revisit in the literature. However, while these papers have in large part being about drawing out some false assumptions in the literature and providing new hypotheses about sexual selection that could be looked at in the fossil record, they were a bit short on how this could be done, and were if anything, narrow in focus (not that Ornithodira is a small group, but its got nothing on Animalia).
So then to a paper in TREE that came out yesterday online. Led by entomologist Rob Knell, it also includes Darren Naish and myself and attempts to provide a review of the entire question of sexual selection in the fossil record. We look at ways in which this could be diagnosed, some false dichotomies and assumptions that have been put forwards in the past, try to identify some key features that may help diagnose sexual selection and look at some of the more convincing cases for this that have been put together to date. Clearly there’s a limit to what we can get into under 10 pages for what is supposed to be a review, but I think there’s some nice synthesis in there and a bit more “we can try doing this”-type stuff, that just covering what has been said before. Anyway it’s out and available (though behind a paywall, sorry) so go take a look.
Happily for me I have been contacted by several colleagues in the wake of my last post pointing me to the specimens and papers that I’d either missed or have come out too recently for me to have included in the tails paper. More happily still a couple of them are really interesting and so worth sticking up here. Remember that I’d been scaling the length of the tail against the femur as a proxy for body size with most values being around 3-4 (i.e. the tail was 3 or 4 times the length of the femur) with the very shortest clocking in at just 1.2 or 1.3 and the highest at 8.8.
First off, Jordan Mallon pointed me to a paper of his describing a chasmosaurine with a complete tail that clocks in at just 1.9. The next lowest value I had for any ceratopsid was 2.8 so this is a quite a big drop and this is the same as Nomingia which I think is fair to call a very short-tailed oviraptorosaur. So there’s at least one more shorty out there.
I’ve also been mailed by Matthew Herne who’s working on Leaellynasaura and given me permission to publish this nugget of data here before his full description makes it into the literature. Now Leaellynasaura did get a mention in the paper as being a possible outlier with a long tail based on an SVP abstract by Matthew, but obviously without the actual data I had no idea just how low this might be. Well, as I say, he’s mailed in the result and it’s a truly whopping 12.4! It’s tail was more than 12 times the length of it’s femur. Wow.
Tags: anatomy, Dinosaurs, evolution, museums, tails
So I have a new paper out and inevitably I’m going to talk a bit about it on the Musings. While I’ve had a few abstracts and the odd short paper out as sole author, this is pretty much my first proper effort in a major journal where I’m the only author. Not that I didn’t have help of course (which is what the acknowledgements are for) and I do especially want to take the opportunity up front to thank various people for their contributions and help, but most especially Susie Maidment for her help in data collection.
Right, onto the actual paper. Way back in 2010 I was looking at pterosaur tails in connection to an anuroganthid that turned up with (for one of them) an unusually long tail. This got me thinking about dinosaur tails and it struck me that while we obviously had some taxa with short tails (like Caudipteryx) and some looked pretty long (like Diplodocus) that no one seemed to have looked at just what kind of variation there was. Moreover, the more I thought about it, and the more I looked through papers and collections (and then later on asked various colleagues) the more often I came across ‘complete’ specimens that were nothing but when it came to the distal caudals. And so began my investigation into the tail lengths of the non-avian dinosaurs (though admittedly Archeopteryx sneaks into the paper as do the scansoriopterigids). Obviously the paper is there to be read, but hopefully this will serve as a quick summary and discussion of the basic points for those who can’t get it or don’t want to read it.
The first thing to note is that actually we really do have very few dinosaur fossils with complete tails. Despite a good hunt through the literature, a couple of collections, and exchanges with a number of colleagues I was able to track down very few specimens where every caudal was known. Even in things from localities like the Jehol and Solnhofen where skeletons are preserved in beautiful condition and soft tissues are common, there are actually very few specimens with every caudal vertebra preserved. Sure the sauropods might expect to do badly given how incomplete they always seem to be, and we’ve got more than a few dinosaurs known from only fragmentary remains. However, on the other hand we now have thousands of dinosaur fossils, and some species are known from dozens or even hundreds of good specimens and many of these are from sites of excellent preservation. But for all my searching and asking, I found less than 20 dinosaur specimens in total that have every caudal preserved. That’s really very low. Even things like ankylosaurs and dromaeosaurs with those lovely reinforced tails don’t seem to do any better either, complete tails are really, really rare.
Now there are a good number that are probably close to being complete with only a few distal ones missing, but obviously quite how true this may be is hard to determine. Sure there tends to be a general tapering of the size of the caudals which can give you a reasonable guess as to where it likely ends, especially if they are very small when they stop, but things like Diplodocus with it’s near endless rod-like caudals or the sudden stop in Nomingia means you could easily be wrong. In short, while a specimen like Sue we can probably have a pretty good guess how long the tail was and quite how much was missing, for plenty of other species it’s not going to be so easy. And things get worse from here.
Not only are there few dinosaurs with complete tails, but in one wonderfully illustrative case we have some major intraspecific variation. Two specimens of Leptoceratops are preserved side by side and so we can be confident that these aren’t just the same species, but are even from the same population. The problem is, one has 10 more caudals than the other, and their tails are proportionally rather different in length too. There’s quite a bit of intraspecific variation there, and indeed a look across other amniotes suggests that this is quite common – caudal counts and caudal lengths can vary a lot in tetrapod species. Tail length is sexually dimorphic in some snakes for example, and can vary a lot even in mammals.
Interspecific variation can be high too, which means it may not be safe to reconstruct missing tails from even close relatives. The wonderful little Epidexipteryx has the joint shortest tail known for any dinosaur that I found, but it’s sister taxon, Epidendrosaurus, has one of the longest tail known (and that one is incomplete and would have been longer still). While this might be an unusual case, there’s a decent bit of variation seen in a couple of other clades too.
All of this means that we need to be a fair bit more careful when talking about dinosaur tails and especially when it comes to recounting their size in terms of length. The length of a dinosaur is absolutely ubiquitous in the media as a measure of size and it turns up in a few papers too. However while some taxa are of course known absolutely in terms of their length, and many are probably about right despite being not entirely complete, others would seem to be little more than a best guess – and a best guess based on not very much to be honest. The data for sauropods in particular seems to be incredibly sparse and accounting for the inter- and intraspecific variation seen, I don’t think I’d be confident in reconstructing the tail of something like Argentinosaurs to within even a 50% error – it could be really long or very short and there’s no way of picking one over the other. Even ignoring some of the outliers, there’s a fair bit of variation there and can have quite an effect on the appearance of an animal.
Scott Hartman has been good enough to make this for me – a Spinosaurus with a short, ‘normal’ and long tail. All of these kinds of lengths can be seen in various theropods and to my mind are all plausible – indeed, we’ve been quite conservative here and could easily have copped off another hatful of caudals or plugged on a good few more and the results would still be quite plausible and within the bounds seen by other theropods. Of course note that while the length of that tail in each varies enormously, and as such, so too does the total length of the animal, the mass would not change that much. A 16 m long Spinosaurus sounds massive compared to a 12 m one, but if the only difference is in tail length, then in terms of mass there might not be much in it, just a few tens of kilos in a multi-ton animal.
So, estimating the length of a dinosaur without a mostly complete tail could give you a rather inaccurate number. There does seem to have been a fair bit of inaccurate information out there in the literature in the past with people giving ranges of caudal counts for groups when individuals were known with much higher values, and clades being described as having ‘long’ tails when they didn’t (or there was no real way to tell). However, there is a little more to this, I also did an analysis where (as far as possible, which admittedly wasn’t that far) the variation in tail length was compared to snout-vent length.
When examining living species, most biologists use snout-vent length as a proxy for how large animals are. After all, the tail length can vary a lot as we’ve seen, and even weight isn’t a great measure for a lot of living animals as it can fluctuate a lot on an annual basis, and of course isn’t available for specimens in museums. So a measure from the tip of the snout to the vent / anus is a common measure of size but we don’t seem to use it much in palaeontology (and certainly not for dinosaurs). In short therefore, we’re using a measure which not only includes a lot of variation in the tail that might screw up the results (and that most of the time we don’t know for sure anyway), but it’s not compatible with other datasets on extant taxa. The question is though, would the equivalent be any better for dinosaurs?
My simple analysis suggests so – that from the available data, tails are rather more variable in dinosaurs than the body. As for the vent, well, that we obviously don’t know exactly as a decidedly soft tissue structure so I plumped for the last sacral being a point that would be close to the vent and an unambiguous point on the skeleton that would be easily identified and would likely be preserved. This measure (snout-sacrum) is one I suggest we should start using when we want to talk about dinosaurs sizes in terms of length.
So there you have it. We don’t seem to have too many dinosaur tails, those we have suggest much inter- and intraspecific variation and so estimates of total length or using total length may not be very reliable. Snout-sacrum length is probably more reliable and in any case would bring the data in line with that used by most biologists. My final note though is an appeal – despite the work I did trying to uncover dinosaurs with complete tails, I’m sure I’ve missed some. Perhaps they’ve simply not been described, or are squirreled away in obscure journals, or are only listed as paratypes etc. I have seen a couple of things published since this work was finalised that look like the tail is complete but where the paper doesn’t actually say and it’s not entirely clear from the figures. I can’t believe that some of those massed ranks of undescribed Psittacosaurus, Protoceratops and various massed ranks of hadrosaurs and iguanodontians don’t have a few more complete ones lying around that can be measured. So if you do know of any specimens out there with complete tails (and better yet, totally complete specimens in terms of the skull and vertebral column) do please let me know. I’ve exhausted all the easily available avenues to date, but I’d love to do the analysis again with much more data. One day.
Tags: archaeopteryx, birds, Dinosaurs, evolution, feathers
It was suggested to me not too long ago that I might well have the best and most extensive collection of images of Archaeopteryx specimens online. Between having seen quite a few of these on display and having taken photos myself, plus the near endless collection generously sent on by Helmut Tischlinger of his UV works, nearly every specimen is on here and most with multiple views, close-ups and in UV. I am still missing a couple, but I’d have to agree that I’ve yet to see any online collection that can rival mine. Still, they are scatted around all manner of posts and so aren’t necessarily that easy to find. No more, here’s they are all are for convenience.
If you have others you are happy to share and have permission to distribute, do please let me know and send them on. This is simply there as a reference collection for people to learn and work with, but obviously more (or better, not all of these are great) would be lovely to have and make this still more useful. I know there are some scans and images out there and it’d be great to round this out as a clearing-house for people who want to see and compare these specimens.
Readers will remember a beautiful fossil from the Solnhofen being shown on here back in November of last year. People who have access to the internet will probably now now that yesterday the first formal publication on this animal came out. It’s now named Sciurumimus – the squirrel mimic – on account of the rather bushy tail. There’s already a ton of discussion on this online and quite some hefty coverage so I’m not going to dive into the ins and outs of feather distribution in theropods or the phylogenetic position of it. It is worth comparing it to Juraventor of course – sister-taxon to Sciurumimus in the analysis and from the same beds. Despite the obvious gross similarities, the authors do note a ton of small differences between the two that suggest they are genuinely distinct.
Of much more interest to the readers though will be the fact that once more Helmut Tischlinger has been generous enough to send me a variety of nice images with permission to publish them here. At least one of these isn’t in the paper and the res is pretty good so even those of you who’ve been able to peruse the PNAS paper might do well here, so enjoy. As usual my thanks to him for this very generous act and a reminder that these are his images and should not be reproduced without permission etc.
Tags: Dinosaurs, museum
The Horniman museum is rather bereft of dinosaur material. There are some Igunaodon vertebrae in rather poor condition, there’s some trackways hanging around, and though I missed it, I’m assured there is a Triceratops rib on display. Given the size of the museum vs the style of the collections that’s not a criticism, but no real natural history museum can really count as such without at least a token effort at some dinosaur display and this is no exception. There are several small life reconstruction models of dinosaurs dotted in the halls to illustrate various issues and here they are.
Yes, they are rather out of date to say the least, and it’s quite a surprise that there’s no theropod or sauropod at all, just ornithischians. Still, they are rather endearing and I really like them in terms of style, though obviously from an educational standpoint they could do with being a bit more up to date (and how long as Scolosaurus been sunk into Euoplocephalus?). The detail is nice too, though the Stegosaurus is probably the best (and appears to have walked straight off the set of King Kong) and I only find now that my photo is rather out of focus, sorry about that.