Posts Tagged 'tyrannosaurus'

A fifth anniversary tyrant

The next few days are likely to be very busy for me and this weekend I’m off on holiday, so I very much doubt I’ll be blogging on next Monday. This is a bit of a shame as those who occasionally glance at the bottom half of the sidebar on the Musings will realise that it pretty much marks the 5th anniversary of the blog. Of course very longtime readers will know I was going for some months on the old Dinobase site before cranking up this version on wordpress, but this has for most people always been the home of my pronouncements, even if there is also now Pterosaur.net, the Lost Worlds, and various bits on other parts of the web too.

So I’m naturally really rather pleased to have reached this mark, having also not too long past gone over 1.25 million hits and 1250 posts on here. It has, obviously, been a lot of work. While naturally there have been plenty of short posts (even one liners, and those of just a single image) and a fair number of guest pieces, I’ve obviously poured a huge amount of time and effort into this over the years, and I’d like to think it’s made a fair impression on a goodly number of people. Plenty of great dinosaur blogs by interesting and talented researchers seem to have fallen by the wayside, so if nothing else I can claim a fair bit of persistence.

Right, well to ‘celebrate’, here’s some pictures of a Tyrannosaurus mount from the Tyrrell that I was going to post anyway (so hardly the greatest party ever thrown really). Still, it’s hardly an inappropriate thing to include as I have done my share of tyrannosaur work and this is a neat mount. Oddly, I wasn’t too happy with the photos originally, you can’t see too many details, but I rather like the way this looms out of the murk with the animal trailing off into darkness.

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Although the skull looks great from either side, once you get a shot up the nose, it’s rather clear how distorted this is. There’s quite a bit of difference between the two sides and it’s obvious there’s been a fair amount of squishing to the bones to give this rather asymmetric appearance.
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Well, that’s it for now. Not sure if there will be another 5 years, but I’m not planning on stopping just yet and I’ll be annoyed at least if I don’t reach 1500 posts having gone this far, though with my other commitments, it may take a good long while yet.

More fun with toys

A couple of weeks back I posted about the little Zhuchengtyrannus model from Japan I got through the post. I managed to get in touch with the company responsible and asked if I couldn’t buy a few more copies from them for my colleagues. Instead they were kind enough to send me a complete set of the model series to which ZT belongs and I thought I’d share them.

They are (top to bottom and left to right): Tyrannosaurus, Stegosaurus, Triceratops, Allosaurus, Yutyrannus and Sinoceratops. Sadly it seems though my little tyrannosaur has the least consistent paint job going as the rest all seem to be a little better done, and the colours etc. are a bit more consistent. I really like their T. rex, though the green mohawk looks very out of place, and bizarrely the Yutyrannus model has the eyes painted in the antorbital fenestra, but overall they are still a nice set. One really cool thing is that the Allosaurus comes with a replacement tail that also attaches to the Stegosaurus and the bases also interlock so you can create an alternate tableau:

The giant, feathered tyrannosaur Yutyrannus huali

So perhaps inevitably the fossil beds of Liaoning in China have coughed up yet another fascinating feathered dinosaur. Yutyrannus huali (which translates as the ‘beautiful feathered tyrant’) is big – as big as some of the Late Cretaceous tyrannosaurines with the largest specimen being around 9 m long and estimated to have weighted close to 1.5 tons. In short, this was big. And feathered. While they are not brilliantly preserved, they are clearly present in places and directly associated with the skeleton as should be expected.

There are a few interesting things about this and I’ll go over them in turn, though as ever the first port of call should really be the paper for the real nitty gritty. First off, the specimens themselves – there are three of them, so this is already a well known animal, and two are basically complete. There’s a lot of anatomy right there and yes, I have to confess, rather more than some other tyrannosaurs I could mention. Indeed two of them are preserved together, as a pair, which nicely hints at least (well, I’m going to say so) at the possibility of sociality (theropods being more social than previously suggested, how interesting?).  Multiple specimens are always great and animals this size being preserved at all are quite rare in the Jehol, so it’s pretty impressive we have three of them. They are also preserved in that psuedo-3D manner I mentioned the other day so there’s really quite a bit of detail there and they are not badly crushed or mashed (as you can see in the pictures below).

Now it is of course already known that tyrannosaurs were feathered, with the basal Dilong being preserved with feathers. The question is of course, did the bigger ones like T. rex have them? There’s been suggestions that they didn’t as they could overheat and there are hints of scaly, feather-less skin from impressions refereed to Tyrannosaurus. So while at least some tyrannosaurs certainly had feathers, and large ones certainly could have done, this is definitive evidence that they genuinely did. The size issue is of course interesting since indeed, very large animals tend to reduce insulation to avoid overheating (elephants, rhinos, hippos etc. are not that hairy and indeed elephants can struggle to keep cool). The obvious exception being animals that live(d) in cold climates like mammoths, and the researchers note that actually the environment Yutyrannus lived in was likely rather cooler on average than that occupied by a number of later tyrannosaurs, so this may indeed have helped them stay warm.

Below are some pictures of the various fossils. While you’ve probably seen a number of these before on all the other sides my insider contacts means I’ve been sent a few to use which were neither in the paper nor press release. So there’s something novel here for everyone, even if it’s not in the text.

Top image by Brian Choo (used with permission) and the rest courtesy of Xu Xing and colleagues.

Xu, X. et al. 2012. A gigantic feathered dinosaur from the Lower Cretaceous of China. Nature. doi:10.1038/nature10906

Tyrannosaurus vs Spinosaurus vs Giganotosaurus vs Mapusaurus vs….

A few years back I wrote a post entitled ‘Tyrannosaurus vs Giganotosaurus’ as I happened to have permission to post a lovely photo comparing the skulls of each and a leftover image of my own of various big theropods. Perhaps inevitably this has been my most viewed and most commented on post ever, and it’s one that’s regularly thrown up by searches, generally involving Spinosaurus too. However, oddly enough much of the ‘discussion’ and views seem ultimately to be simply about big and bad carnivores. Ask a biologist is not immune to the obvious desire for people to know about large predators and their ability (or otherwise) to beat up other carnivores.

Now from the perspective of a palaeontologist / biologist my answer is generally a simple one – who cares? These animals never met and could not have done so. Even IF they somehow managed it, they would almost certainly not engage in any kind of full on fight to the death. Even if they did, what would that tell you really? I’m sure there were bigger adult rexes than the smaller Giganotosauruses say, but bigger G.s than the smallest Tyrannosaurus individuals. So you have to compare theoretical maximums or averages, but that may not mean much if you’ve ever seen a hyena go for a lion or wolverine go for a bear. Big is not the same as bad, let alone victorious.

None of this will tell you anything about the animals at all, their biology, evolution, life history, lifestyle, ecology or behaviour. It’s an understandable preoccupation for kids and while I don’t think it’s worth the hassle it can be a window into further thoughts and interest.

Which do you think would win? Why do you think that one would win? Could we look at any of those things in fossils? Bite marks, bite strength, mass estimates, tooth shapes, eyesight, acceleration, intelligence – all of these things have been written about seriously by palaeontologists and zoologists with all manner of detail and information available. Reasonable inferences can be made by looking at living species and how they behave (what do different predators do when they encounter one another?) not to mention variation within species about how they are built and how they might act.

The question might be mundane, even vacuous, but there’s much that can be discussed and more importantly learned, if the question is a hook to expand people’s horizons and interest.

 

Now to sit back and wait for all the comments of “But t. rex wud win coz he is THE KING!!!”.

Jane’s pathology

Pathologies have had the odd mention on here before (like here, here and here) and this one is rather minor as they go. It’s on the foot of the Tyrannosaurus specimen known as Jane. It’s pretty small, little more than a swelling and roughened bone on one of the pedal phalanges. Still, it suggests there was a fracture on infection at the site and this animal had clearly suffered some kind of injury in its young life. Hardly uncommon, but neat all the same.

Theropod sociality

My recent paper on sexual selection touches on quite a few areas of dinosaur and pterosaur ecology and possible behaviours. Most notably (or rather, of most likely interest to people who like dinosaurs) is what we have to say about the possibilities for degrees of sociality in theropods. The idea that some theropods (and yeah, inevitably, especially dromaeosaurs and tyrannosaurs) may have lived in groups seems to be the subject of more debate, disagreement and hyperbole on the web than any other subject (and I bet there’s more coming in the comments), and yet there is remarkable little actually written about this in the literature. There is now a little bit more though.

Space limited what we could say but there are two points that we did get in and are worth elaborating on just a little here. First off, for those theropods rocking crests, these are more likely to be taxa regularly engaging in social interactions. That’s not to say they were necessarily living in groups, they might still have been solitary. However, they might well have encountered each other often in territory disputes, or even engaged in activities like lekking. Basically a big and honest signal can be a good advert of your fitness (or overall health) and thus you can avoid serious combat with another theropod that covered in claws and teeth that you’ know you’d lose to. Thins like the evidence for craniofacial biting already shows this kind of thing may have been going on, but this is taking it from another, if related, angle.

Secondly there was a paper not too long ago by Roach & Brinkman on the evidence for sociality in Deinonychus. In general they made some very good points and noted that much of the evidence purported to support this idea was questionable at best. However, they also argued that there were no cooperatively hunting extant archosaurs and thus this could be ruled out from an extant phylogenetic bracket point of view. Now one needs to be careful about quite how ‘sociality’ or ‘groups’ or ‘cooperation’ are defined, but as we note in the paper there are a variety of birds which hunt together, even cooperatively, and in the case of some hornbills – on the ground. By any measure that would seem to be a great analogy for small theropods and show that it’s not unknown in birds. There’s even evidence for degrees of cooperation in caimen and yes, going further out from archosaurs, komodo dragons. Coupled with the inherent strong plasticity of behaviour, I don’t think there’s any good reason to rule this out.

Now there’s noting there that definitively rules it in either, but I do think it likely that at least some species of theropods were at least highly tolerant of each other as individuals, and might well have formed socially structured, functioning groups. We have all but the flimsiest of evidence for that right now, but that’s no surprise really given how hard it is to get evidence of this kind of thing. However, there’s certainly no reason to say it was impossible and analysing the available evidence and searching for more is pretty far from a fruitless task.

Rex heads

Following my last few posts clearing out my archive of photos of theropod skulls here’s a couple of Tyrannosaurus heads in near ventral view. The upper one is from Oxford and has, I think, a nice background in the glass roof panels, while the lower image is from the IVPP in Beijing.

A little more on teeth

Since it generated so many comments and discussion about the origins and use of the phrases, I went googling phrases associated with Tyrannosaurs teeth.

Here’s the search terms and the number of hits (to the nearest thousand).

Tyrannosaurus teeth bananas – 792 000

Tyrannosaurus teeth steak knives – 13 000

Tyrannosaurs teeth railroad spikes – 98 000

Tyrannosaurus teeth bananas steak knives – 8000

Tyrannosaurus teeth bananas railroad spikes – 3.2 million (which must be wrong)

Tyrannosaurus teeth steak knives railroad spikes – 8000

Tyrannosaurus teeth bananas steak knives railroad spikes – 6000

Having explored a bit some of these are probably high – people can discuss Tyrannosaurus relative to other theropod teeth and call those steak-knife like especially, so that could be misleading. However, what is clear is that these are all being used with great regularity. My exploring also revealed a profound lack of qualifiers (e.g. ‘big’, ‘crown’, ‘shaped’, ‘similar to’ etc.) and they generally seemed to be flat comparisons of the “teeth like bananas” kind. This included all manner of less-than-stellar sources like AiG and Yahoo answers, but all the way through to Wikipedia, various museum and university websites and more. In short, these really seem to be pretty ubiquitous on the web.

Teeth like steak knives or bananas or well, tyrannosaur teeth

You can’t go too far talking about Tyrannosaurus without coming across one of two great statements, that they had teeth ‘like steak knives’ or teeth ‘the size of bananas’. These are both really, really annoying, in that they sort of convey semi-accurate information while at the same time being really, really misleading. I thought I’d take a little time today to bust these two with a swift one-two and leave at least one corner of the internet with a little less pseudo-information.


Let’s start with the size issue. I can see the concept behind this, a big banana is not so far removed from a big Tyrannosaurs rex tooth. The only trouble is that of course there are lots of smaller teeth in the jaws than just the biggest ones in the maxilla. And of course bananas vary enormously in size and length, so it’s not the greatest unit of size for scale. And of course if you *look* at a Tyrannosaurus tooth, (ooh, look what photos I happen to have, how handy) then things get a bit more complex. Even the biggest crown is not that long, so actually even a pretty small banana is probably bigger (well, longer, another issue of course) than the crown. And since that is really what we should be dealing with, it becomes rather pointless. Ironically the roots are so big that if you include them, then the tooth is huge and much bigger than even the biggest bananas that I have seen. So as a measure a banana is either too big OR too small at the *same* time. Impressive! And not really the same shape either. In short, please people, let’s stop using this as a description of tooth size for Tyrannosaurus.

And so to steak knives. First off, take a look at this:

While the two images above were in lingual and labial views, this is an anterior shot of the tooth. If you get something that fat and rounded handed to you by a waiter the next time you order a steak you but wonder if he wanted you to tenderise it rather than cut it up. The tooth is damned near circular in cross-section and about as far as you can get from a ‘knife’ if you tried (and indeed is less blade-like than any other theropod tooth). As we know, Tyrannosaurus had a bone-crunching bite, so what’s with the knife analogy?

I’m certain it dates to a paper by Abler where he examined the effects of the serrations on Tyrannosaurus teeth and concluded that the *way* in which they cut was most similar (at the microscopic level) to that of a steak knife. Note that this means that those tiny serrations on the teeth are cutting *like* the giant serrations of a steak knife. This doesn’t mean that they acted like one though. If I stuck that thing into your arm or chest with the power of a rex bite I rather suspect what would most impress on you (other than the need for extremely urgent medical attention) would be the massive and sub-circular puncture wound and not the nice little edge to it in a couple of places.

As such, again, please stop describing these as ‘like steak knives’, a small part of them does, superficially cut like a steak knife, but they are not shaped like them and don’t act like them and aren’t used like them.

Carnegie Tyrannosaurus pt 4: Jane

In addition to a not inconsiderable rex collection in the dinosaur hall, the Carnegie also has a cast of the juvenile Tyrannosaurus ‘Jane’ striding around the corridors. Yet another specimen I’d not seen before, this was a great lesson in ontogeny as even the briefest glance shows that the head here is quite small relative to the body and the legs appear absurdly long. This is an animal yet to grow into it’s powerful adult form – even the skull looks pretty narrow when seen from the front.

A nice touch was the fact that this was mounted close to the ground and not miles behind some barrier so I was able to get a pretty good look up close and see some details (which also shows off the quality of the casting). A great little find and quite unexpected.

Carnegie Tyrannosaurus pt 3: dentary

I’ve yet to have the chance to mention that in addition to all the superb specimens and mounts on display, the signs and details of the Carnegie exhibits are superb. Most mounts are accompanied by a smaller specimen of some description with additional details about its provenance or relationship to the main skeleton. This of course helps to reinforce the idea that we often have multiple specimens of given taxa and that different things can preserve or be found in different places etc. and our knowledge is built from a patchwork of material. In the case of the Tyrannosaurus display, the two adult rexes are accompanied by this rather nice dentary and a details such as an original exchange of letters about the purchase of one of the skeletons. It brings a nice touch of more recent history to things that otherwise date from the Cretaceous.

Carnegie Tyrannosaurus pt 1

Yes this is only part 1 because there is quite simply so much Carnegie Tyrannosaurus material on display to cover. And here’s the first and most important – the holotype of T. rex, what is, in effect the very definition of what Tyrannosaurus actually is. It’s a superb mount and sits over the carcass of an Edmontosaurus and with the head rather dipped which makes it easy to get to see this up close which is nice. Three more posts to come, so stay tuned.


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