Zhuchengtyrannus strikes

Well you knew it was coming right? Yes Zhucheng does now meature a mounted Zhuchengtyrannus. Or rather inevitably, more accurately, it features a T. rex mount with the maxilla and dentary replaced with cases of the holotype. This is quite clear on the photos below as the added parts are of rather better quality and have been pained a little differently too. OK, so otherwise this is basically just another rex mount but forgive me for liking it. And it is in the process of absolutely mashing a juvenile Shantungosaurus, so what’s not to like?

Dinosaur data storage

Not as you might think a new archive of dinosaur data, but this, a dinosaur that stores data:

One of my students was awesome enough to give me this as a gift for supervising her undergraduate thesis work (which included my little trip to Germany in December). It’s rather obviously a tiny tyrannosaur with a USB drive fitted, but awesomely, it’s been painted to match a certain overexposed tyrannosaur. This is truly wonderful and I am most grateful – the only problem is I’m frightened to use it!

For anyone not totally sick of this dinosaur, you can check out my appearance on live Irish TV for a week or so back (follow this link and go back to the 27th of April).

Guest Post: Illustrating Zhuchengtyrannus:

Yes another guest post and yes we’re back on the tyrannosaurines again. While I’ve already talked somewhat about the impact of the artwork (that by now everyone is familiar with) I’ve not talked process. Here is a chance to make that up as Bob Nicholls returns to the Musings again (see here, here and here for starters!) to talk about how he created this piece. My thanks once again to him for his superb work:

Being the first artist to illustrate a new species of extinct animal is a great honour.  The series of events that are required to successfully fossilise a dinosaur and for that individual to be revealed to the world millions of years after death is an epic story.  In brief, the dinosaur first died in a location where its remains were covered by sediment rapidly.  The animal’s remains then hid within the Earth and lay undisturbed for a length of time we cannot imagine.  During this vast period the dead creature’s species will evolve out of existence and new life forms will survive catastrophes to colonize our planet.  Eventually a species of energy hungry ape developed an interest in investigating planet Earth’s history and against the odds our fossilised dinosaur was discovered. One of the apes, let’s call him Dave Hone, then decided to reveal the dinosaur to his entire ape species and asked a friend, let’s call him Bob Nicholls, to illustrate the wonderful discovery.  It may sound like a simple tale, but if you really think about it, it is astonishing.  To be a small part of it makes the hair on the back of my neck stand up.  There is no greater honour for a palaeontologist than to be the first to show the world what a long extinct animal looked like.  Especially a tyrannosaur!

Sketch for the life reconstruction of Zhuchengtyrannus. Courtesy of Bob Nicholls.

The illustration of Zhuchengtyrannus took me about eight hours in total, from the first preliminary drawing to e-mail delivery.  The first sketch was a satisfactory pose but four re-draws were required to make small adjustments to the teeth, snout, nostril and eye.  When Dave was happy for me to render the colour artwork I painted it with acrylic paint on illustration card.  I chose to paint the colour scheme of a show-off male with an eye stripe and blood red patches for impressing the tyrannosaur ladies.  I wish Dave and I could have worked on the piece a little longer but it was an excellent and most enjoyable day’s work.  Zhuchengtyrannus is dead, long live Zhuchengtyrannus!

Zhuchengtyrannus life reconstruction by Bob Nicholls

OK, so I’m just milking it now – final Zhuchengtyrannus roundup

Yeah, this is still creeping along. I’m trying to stop honest and while I’m sure I’ve lost most people by now, this is more or less the end of it. (More or less because there are ZT related things to come but which won’t actually really mention the damned beast itself so from here you’re basically safe). This has, understandably, been a hectic week and I’ve still got bits of work to do related to this so I’m not quite done, even if the blog is.

Going all the way back to the Eeeek! post, I want to again thank people for being helpful and not jumping me with ZT appearing all over the web before we were ready. It is much appreciated and helped us get maximum impact with the media. On that note, I’ve yet to put up this link to the University College Dublin page where there are links to a great many of the online media about Zhuchengtyrannus including a video of me talking about it. If you’re not interested in hearing me say things you’ve already heard or read 50 times over on here then you can try and identify all the various dinosaur and pterosaur books on the shelf behind me. Fun for all the family (possibly).

And while I’m here, here’s links to all the previous posts on here introducing this guy, notes on the taxonomy, ecology, size, and artwork. And if really like this, go do a Google image search for ‘Zhuchengtyrannus’, it’s quite startling.

 

The art of Zhuchengtyrannus

Zhuchengtyrannus life reconstruction by Bob Nicholls

I have my longtime Musings friend Bob Nicholls to thank (well, we did pay him too) for the superb art of Zhuchengtyrannus that has accompanied the release of this work into the media. The original and Bob’s pencil sketch will soon hang proudly on the wall of my office (they’re being framed right now).

What Bob has produced is, I think, quite beautiful, but there are a couple of features in there which the sharp-eyed (or overly nit-picky) may have spotted that are worth discussing as they illustrate some of the issues of producing such a work and how things can be done to highlight certain issues or produce an effect for the reader. While much can, and has, been written and discussed about the various aspects of palaeoart (or palaeontography if you prefer) this is a nice opportunity to go a little further.

First off there is one too few teeth in the dentary. This is basically my fault (or if you want to be more generous to me, that of the authors collectively). We originally misinterpreted the broken small tooth socket at the front of the dentary, that many tyrannosaurs have, as being part of a very large first tooth. That is, the first and second sockets were smushed together and we thought they were just a single large one till a referee correctly spotted this error and we corrected it in the paper. By this point Bob had already turned in his work and it was too late to do anything about it. To be more accurate, we never told him! So if you’re reading this now Bob, feel absolved of any blame, but I didn’t tell you because I felt guilty and didn’t want you to have to go to any trouble to correct it and assumed that no-one would know or care (though I’m rather destroying the first notion by writing this).

Of course, if anything the teeth are too correct in that (first dentary tooth apart!) they are all there. Theropods shed their teeth quite regularly and it would be normal for one or two to be broken or only half exposed in the jaw rather than a nice neat row as seen here. This of course introduces the main point I wanted to make in this post: this artwork (like many others) is supposed to be illustrative. It’s created to communicate something about the animal as a living organism to people based on the fossil bones. Many people seeing this would likely be hindered, not helped, by such details and would be wondering why the teeth were uneven and oddly positioned. This artwork, (with the Musings being the only likely exception) will not be accompanied by expert commentary on theropod anatomy and physiology and was destined for consumption by the general public so keeping things simple was the order of the day. (Though for the record, Bob and I never discussed this, his draft had the teeth like this and I thought it fine to keep them like that).

Zhuchengtyrannus maxillary sculpting. From Hone et al. in press

Similar to this, the sculpting on the maxilla (seen here) is particularly prominent, and while this is a common feature of adult tyrannosaurines, to my eye at least, it’s a little bit more pronounced than I’ve seen in other tyrannosaur specimens. As such I asked Bob to emphasise this in the artwork. In reality, the muscle and fat layers and even the skin itself were probably thick enough that looking at the living animal this would be invisible, or at least rather more subtle than seen here. But again, the point here was to emphasise a characteristic of the bones in the art – to provide an obvious point of reference for someone who knows nothing of dinosaurs to make the connection between the bones and the life reconstruction.

I can see that not everyone might be happy with this. But my take would be that you have to tailor the picture to the audience and the level of information that can go with it. In emphasising the sculpting and keeping the teeth regular there is nothing especially odd or outlandish about this. It is accurate and reasonable (plausible if not probable if you like) and deviates only a little from what you might consider a perfectly accurate or perfectly probably reconstruction (this after all, is not what a human looks like – it’s informative, but not necessarily realistic as such). If I were to get this done for a dinosaur book where I could wax lyrical over several pages or include key notes and labels then I’d probably actively want to add missing teeth and reduce the sculpting to emphasise these very points, but in the circumstances this was the best way to convey the maximum information with the minimum amount of confusion.

So just how big was Zhuchengtyrannus?

After all these posts, I’d understand if you were sick of this thing by now, but there is still (sadly for you) some more to discuss. One thing that has been left untreated until now on the blog is the size of Zhuchengtyrannus. Knowing the media would immediately want to know*, we did suggest that this was an 11 m long, 4 m tall and 6 ton animal, but really, how accurate are these? And where does that place it among other theropods?

*Indeed, despite including this in our press pack, I was still regularly asked about this, and was asked for ‘real life’ examples as well.

Well first off the easy stuff – we can measure the bones we do have and that gives us a 64 cm maxilla and a 78 cm dentary, though the latter would probably have been a bit longer in life. These obviously make up a significant part of the skull, but it would have been much longer when complete. As noted before, tyrannosaurines are generally pretty conservative so we can compare the sizes of these bones to their equivalents in other specimens for comparison. There are two adult Tryannosaurus specimens with maxillae just 1 and 2 cm longer than that of ZT with one having a bigger and the other a smaller dentary, so it’s immediately fair to call this about T. rex sized. However, the specimen known as ‘Sue’ is a real monster of a rex with a maxilla some 79 cm long, which is a fair bit bigger bigger. There are several Tarbosaurus specimens in the low 60s for maxilla length, with one (I can only imagine is a juvenile) at 49 and a pretty big one at 73. Several other more basal tyrannosaurid and tyrannosaurine taxa get close, but are not quite as big as ZT.

Obviously we just have one specimen and it’s impossible to know if it was a big or small or very average specimen. Assuming the latter, it’s very slightly bigger than most specimens of Tarbosaurus and slightly smaller than most Tyrannosaurus ones. That means it’s basically about the same size as these two, and lying in between on average.

From that of course we take our other estimates of size – while Sue is about 13m long, the others are more like 11 and so in the paper we suggest that ZT was between 10 and 12 m long (or more simply, 11 m to the press). In hindsight the 4m tall might be a bit much, but not by a huge amount, and as ever with measures like this, vary a lot with what the animal is or could do. If it stretched or tilted the head up (OK, perhaps straw grasping a bit) it would probably be over 4. So onto the mass, which is inevitably the most contentious, if only because it’s the hardest to determine.

Long time readers will be aware of the huge range of masses that have been posited for all manner of dinosaurs over the years. While the ranges have been narrowing and the values converging there is still quite a lot of disagreement. Add to that the natural levels of variation between individuals and even the fluctuations of individuals (sometimes they’re fat, other times, thin) and it should be obvious that even if our calculations were 100% accurate, you would still need a range of figures for a given species and even a single individual. For an animal this size that could easily mean that a single specimen could vary by as much as a few hundred kilos and as a species perhaps the biggest and smallest were well over a ton apart or even two. As such any reasonable number is going to be ‘about’ right and with estimates for T.rex typically being around 6 tons (though up to 8 have been suggested) then 6 is a perfectly reasonable number for ZT, and though we really are extrapolating from less than half a skull, the group as a whole is conservative enough that I’d be surprised if we were much out with any of these numbers.

So where does this put this critter in the pantheon of predatory theropods? Well obviously Tyrannosaurus is bigger and Tarbosaurus is pretty much the same. I don’t think anyone would argue that (in terms of length at least) that Spinosaurus, Giganotosaurus and Mapusaurus are not bigger (and here’s a good chance to link to this old image of mine). After that, well, I’m kinda out of bigger ones. While admittedly ZT is in the same position as some possible other rivals (i.e. we have enough o make a good guess but not enough to be certain) I don’t think it unreasonable to suggest that Zhuchengtyrannus sits in the all time top half dozen.

The ecological implications of Zhuchengtyrannus

OK, I admit there’s not actually too much to say about this, but what little there is, is quite important. Zhuchengtyrannus is really rather big – a little smaller than Tyrannosaurus, about the same size as Tarbosaurus and thus as a theropod perhaps bigger than anything except these two, Spinosaurus, Mapusaurus and Giganotosaurus (and more coming on that tomorrow). It was certainly a serious customer.

More boringly, in a way, Zhuchengtyrannus is really quite a normal large tyrannosaurine –the anatomical differences are sufficient for taxonomic purposes but would probably make no real difference to the overall appearance of the animal – that is, as far as we can tell it would look in life very much like Tarbosaurus and Tyrannosaurus. While there isn’t that much of it, what we have is quite normal and it’s reasonable to infer that this animal was occupying a similar niche to the other giant tyrannosaurines (and that means predation and scavenging).

That is in itself a bit of a novelty. As I’ve noted before when discussing spinosaurs, it’s actually quite common to find multiple, similarly-sized large theropods in the better-known dinosaurian faunas. We find Allosaurus, Torvosaurus and Ceratosaurus together, Sinraptor and Monolophosaurus, Charcarodontosaurus and Spinosaurs and so on. Even when it comes to tyrannosaurines we find the smaller Daspletosaurus and Albertosaurus together (not to mention our old favourite Gorgosaurus). However, Tyrannosaurus seems to have lived alone as it were (and you can argue Nanotyrannus, but it’s quite a bit smaller) and Tarbosaurus may not have been really troubled by Alioramus. While we have no direct evidence that Tarbosaurus and Zhuchengtyrannus overlapped directly their fossils are being recovered from very similar times and only a few hundred kilometers apart. It’s really quite likely that they met and of course ZT is itself accompanied by another large tyrannosaur from the same quarry so there could have been quite a party going down.

To employ a much overused phrase, this does rather leave T. rex as the exception that proves the rule – it’s increasingly looking like the only big theropod which doesn’t come with at least one accompanying near-equally sized alternate carnivorous theropod. Despite the ever increasing similarities between the Late Cretaceous faunas of North America and Asia, T. rex does still seem to be, in at least one way, still the undisputed king of his own backyard.