I was going to title this post 'How a tyrannosaur was mounted', or 'How to mount a tyrannosaur', but that seemed childish. Eventually I went for a title based on a movie, as that isn't at all childish. If I could travel in time, high on the list of things to do would be visits to see dead animals: I don't just mean tyrannosaurs and azhdarchids, but also such things as thylacines and Passenger pigeons (think kilometre-wide super-flocks that took days to pass overhead, drowned out all other sound with their din, and blotted out the sun). But also high up on the list of priorities would be visits to old museum displays. Unfortunately I never got to visit the old dinosaur gallery at London's Natural History Museum, and I wish I had. Here's why...
[added later on: SEE BOTTOM FOR UPDATE]
When Tyrannosaurus rex was named by Henry Osborn in 1905, it was described alongside a second gigantic theropod, the armour-plated, Ceratosaurus-like Dynamosaurus imperiosus, collected in 1900 near the Cheyenne River, Wyoming. Unlike T. rex, Dynamosaurus possessed irregularly shaped bony plates on its back and sides. These later turned out to be from an ankylosaurid (probably Ankylosaurus), and in fact small craters on the scutes look like T. rex tooth marks, suggesting that the scutes were part of the tyrannosaur's stomach contents* (Carpenter 2004, Breithaupt et al. 2008a, b). Osborn later realised that Dynamosaurus was synonymous with T. rex, but continued to think that the animal possessed armour plates (Osborn 1917).
* Ankylosaurid armour may well have helped protect these animals from tyrannosaurid predators, but the awesome bite strengths reconstructed for T. rex suggest that the biggest tyrants might still have been able to do serious, fatal damage to an ankylosaurid. Scott Hartman once depicted this in a reconstruction titled 'Armor? What armor?'.
In 1960 the Dynamosaurus specimen was (together with parts of three other T. rex specimens) sold to the then British Museum (Natural History), and here it was mounted in the museum's old dinosaur gallery in a rather 'modern' pose: that is, with its body and tail near-horizontal and its tail well up off the ground [the image of it shown above - the only one I could find - was kindly supplied by Dan Varner]. Those who have commented on this have usually noted that Barney Newman deliberately chose to depict the animal in this way: indeed Newman (1970) explained how correct articulation of the vertebrae meant that the animal simply had to be arranged like this.
Newman was not, actually, the first person to depict a tyrant dinosaur in a horizontal-bodied posture. Erwin S. Christman illustrated the T. rex back and tail in horizontal pose for Osborn's 1917 paper on theropods (Osborn 1917: figure shown above), and one might conclude from this that Christman (and perhaps Osborn too) actually advocated a wholly 'modern' posture for tyrant dinosaurs. However, in an earlier paper Osborn (1913) had drawn attention to Christman's on-going work on reconstructing the life postures of theropods: it seems from this that Christman had imagined theropods to walk with their backs held diagonally, and their tails sloping down to the ground. Various dinosaur reconstructions supervised by Osborn during the 1920s are depicted this way too, so I think that Osborn regarded bipedal dinosaurs as 'diagonal-backed', not as horizontal-bodied. Newman (1970) noted that Ned Colbert had reconstructed Allosaurus in a horizontal posture too, but what he didn't note is that the skeleton concerned is mounted in a stooping posture as it's meant to be bending down over a carcass. It is not meant to be just walking along.
So, was Newman's tyrannosaur mount as far-sighted and innovative as might appear? It soon entered the 'mainstream' literature: Halstead (1975), for example, illustrated T. rex in the postures depicted by Newman (incidentally, Halstead also repeated Newman's idea that tyrannosaurs might have used their short didactyl forelimbs as props when raising themselves from a resting posture). But Newman's ideas weren't entirely modern. He thought that the tail must have swung far to the side with each step, and that these dinosaurs must have walked with an ungainly waddle rather than a majestic stride. Modern work has not supported this idea, which never seemed reasonable anyway.
What interests me in particular is Alan Charig's claim that the BM(NH) T. rex 'was mounted with its body in a far too horizontal position: this was done because it would otherwise have been too tall for the Gallery. Newman, who made the mount, has attempted to rationalise this (1970) by stating that the posture was much more bird-like than is suggested by earlier mounts' (Charig 1972, p. 137). I don't know if Charig was right, but we do know that the posture of the BM(NH) T. rex 'did nothing to improve relations between the two' ['the two' being Newman and Charig] (Moody & Naish, submitted).
Whatever the true explanation behind the posture of the London T. rex, I remain upset that I never got to see it.
Finally, SV-POW! celebrated its first birthday recently: for the celebratory blog post, go here.
... and here it is in colour, many thanks to Jim Robins!
Refs - -
Breithaupt, B. H., Southwell, E. H. & Matthews, N. A. 2008a. The 'powerful imperial lizard' Dynamosaurus imperiosus: the world's first Tyrannosaurus rex comes to London. In Moody, D., Buffetaut, E., Martill, D. & Naish, D. (eds) Dinosaurs and Other Extinct Saurians: A Historical Perspective. The Geological Society of London (London), pp. 22-23.
- ., Southwell, E. H. & Matthews, N. A. 2008b. Wyoming's Dynamosaurus imperiosus and other discoveries of Tyrannosaurus rex in the Rocky Mountain West. In Larson, P. & Carpenter, K. (eds). Tyrannosaurus rex: the Tyrant King. Indiana University Press (Bloomington and Indianapolis), pp. 57-61.
Carpenter, K. 2004. Redescription of Ankylosaurus magniventris Brown 1908 (Ankylosauridae) from the Upper Cretaceous of the Western Interior of North America. Canadian Journal of Earth Sciences 41, 961-986.
Charig, A. J. 1972. The evolution of the archosaur pelvis and hind-limb: an explanation in functional terms. In Joysey, K. A. & Kemp, T. S. (eds) Studies in Vertebrate Evolution. Oliver & Boyd (Edinburgh), pp. 121-155.
Halstead, L. B. 1975. The Evolution and Ecology of the Dinosaurs. Peter Lowe, London.
Newman, B. H. 1970. Stance and gait in the flesh-eating dinosaur Tyrannosaurus. Biological Journal of the Linnean Society 2, 119-123.
Osborn, H. F. 1913. Tyrannosaurus, restoration and model of the skeleton. Bulletin of the American Museum of Natural History 32, 91-92.
- . 1917. Skeletal adaptations of Ornitholestes, Struthiomimus, Tyrannosaurus. Bulletin of the American Museum of Natural History 32, 133-150.
- Log in to post comments
More like this
So, what is current view on T-rex posture?
I remember critics saying that with body and head kept horizontally, standing T-rex would fall on its nose.
I do remember seeing that mount when I was very young, probably about 6 or 7 and thus a good 20 years ago at least. Sadly it was taken down soon after that and despite me visiting the NHM several times a year through my life I only have the haziest memories of it. I do seem to remmeber the top was very close to the ceiling in the place that it was mounted which adds weight to the statements above. In the past I have searched in vain for photos of it and am delighted to see this one, but if a colour image turns up do let me know! Nice stuff and fond memories.
Horizontal like in basically all theropods except penguins and auks.
Why?
Perhaps this is just a matter of some definition that I'm not aware of, but isn't an effectively vertical posture actually quite common among birds? For example: owls, cormorants, macaws (and many other parrots), the quetzal (and other trogons), kingfishers, wydahs, woodpeckers, treecreepers?
Because forebody (before the point of support) would weight much more than rump and tail.
I actually do think that some (not all, some) modern 'horizontal' theropods look over-balanced: look at the Aerosteon depicted by Sereno et al. and the Majungasaurus reconstructed by O'Connor & Claessens for example (both here).
However, remember that the biggest, heaviest muscles in theropods were those associated with the pelvis and hindlimb, with the caudofemoral muscles in particular being huge and heavy in most taxa. The thorax, neck and skull were relatively lightweight: tyrannosaurs and others had huge skull muscles, sure, but remember that the skull was extensively pneumaticised (perhaps with the whole of the antorbital cavity occupied by a pneumatic sinus) and hence light for its size. We also have fully articulated skeletons (of multiple diverse taxa) showing that horizontal postures were the norm. It has also been argued that tilting the thorax up too much creates too much stretch on the ischial-based retractor muscles of the hindlimb, and causes the femoral head to disarticulate. Furthermore, the theropod acetabulum is reinforced to receive weight on its dorsal rim, not its anterodorsal or anterior rim (which in turn shows that the ilium was held horizontally in life).
So... horizontal, yes, but still with the possibility of a slightly inclined thorax such as the one shown in Christman's drawings and Newman's tyrannosaur mount. Also, as Greg Paul said in 1988, the possibility exists that the orientation of the thorax and tail differed according to such things as gut-load and muscular condition. I've just remembered, Paul actually wrote a few articles on this very issue...
Paul, G. S. 1996. Tilting theropods and other dinosaurs. The Dinosaur Report Winter 1996, 12-13.
- . 2005. Body and tail posture in theropod dinosaurs. In Carpenter, K. (ed) The Carnivorous Dinosaurs. Indiana University Press, Bloomington and Indianapolis, pp. 238-246.
I do remember visiting the old dinosaur gallery and seeing this T-rex when I was young, which must be now a good 30 years back. I remember there were some interesting murals around the walls (I distinctly remember a Styracosaurus and her young. I'd be intertested to find out who did them. I also remember an Archelon and a Phobosuchus (sic) which really impressed me. I think the latter currently resides in the Earth Galleries
I also really used to love the opld Prehistoric Mammals gallery which had so many fabulous fossils in. Some are still around and folded into the current mammals displays but I'm sure there were far more. Same goes for the dinosaurs.
Yes. I forgot especially about owls and cormorants. What's going on here is that neornithine tails are so short that they can't balance the body in a horizontal position.
Flightless cormorants are nearly as vertical as penguins and auks, aren't they? When owls are on the ground, don't they adopt a more diagonal posture, distinctly different than penguins do on the ground?
So the obvious question, which no-one seems to have asked yet: what the heck happened to the NHM's T. rex? Presumably the material is languiushing somewhere down in the collections, but just who's brilliant idea it was to take it out of the public galleries? And what were they thinking?
Yes, it's in the basement collections except for the dentary which is on display (you see it as you approach the robot tyrannosaur). The NHM purchased parts of four different individuals, originally AMNH 5866 (the Dynamosaurus specimen), AMNH 973, AMNH 5027 and AMNH 5881. I presume that some of these are casts though... I mean, come on, surely the AMNH didn't part with any bits of 5027? (5027 is THE AMNH T. rex).
The number BMNH R7994 is used for the Dynamosaurus specimen, but I don't know how the other parts are catalogued.
Or is it BMNH R799? Have just noticed conflicting codes in the literature. I have notes on the specimen but cannot find them (I used to work on tyrannosaurs, don't you know).
Wait, is that not there any more? Outrage! First they moved Diplodocus into the entrance hall, replacing my pachyderms of childhood, and now this.
Neornithine postures are largela determined by the position of the legs. Swimming birds with the legs at the back of the body either sit fairly vertically (like cormorant, auks and penguins) or not at all (like loons and grebes). The same is true for birds that spend a lot of time perching on branches (trogons being the archetypal example).
Wading and running birds on the other hand, which have their legs more or less under their center of gravity, tend to hold their bodies fairly horizontally. Birds that "slope forward" i. e. hold their head lower than the tail are unusual, but you do see it sometimes, perhaps most often among rails that live in dense vegetation.
Much of course depends on what the bird is doing. Somebody mentioned macaws as an example of a "vertical birds", which is more or less true when they are perching, but when moving on the ground they hold their bodies nearly horizontally (they don't have much choice really, they would drag that long stiff tail on the ground otherwise).
William King Gregory's 1951 Evolution Emerging had restorations of T. rex in a horizontal posture, although with the extra-long Osbornian tail.
Like many issues about theropod functional morphology, simple dichotomies of diagonal/horizontal backbones don't get you too far. Although I agree that most extinct theropods had fairly horizontal backbones (plus or minus 10, maybe 20 degrees; we really may never know very precisely at all).
Living birds and other taxa vary their axial orientation a lot- e.g. pitching downwards the faster they move (in the few species in which this has been measured).
Even ostriches "waddle" (roll their pelves medially/laterally over supportive limbs), just not much; it's a matter of degree, not waddle/don't waddle. I suspect extinct theropods did that too (and moved their tails a bit with each step). Actually there's hardly any way they could avoid some mediolateral motion, and there are decent reasons not to try to avoid it (efficient kinetic-potential energy exchange, for one; stability another; muscle efficiency and coordination, perhaps another). But that is not "waddling" in the exaggerated way typical of wide-bodied birds.
Thus I find "did theropods waddle?" or "do wide-gage footprints indicate waddling?" curious questions to ask. The real question, if any, is how much (quantitatively), and that is a hard one. Alternatively, one can enjoy drawing some arbitrary line between waddle/don't waddle.
Well, as far as I can see there seems to be plenty of headroom for the T. rex in Jim Robins' photo. I met Barney Newman once, not that long before he died. A bit of a character...
"I actually do think that some (not all, some) modern 'horizontal' theropods look over-balanced: look at the Aerosteon depicted by Sereno et al. and the Majungasaurus reconstructed by O'Connor & Claessens for example (both here"
Augh! Those reconstructions are horrible. And one should be careful not to draw too many conclusions from them. May I direct your attention to Scott Hartman's Majungasaurus? You certainly cannot say its over-balanced!
http://shartman.deviantart.com/art/Majungasaurus-87892198
Though probably less so, because in ostriches, like in AFAIK all birds, the acetabula are fairly widely separated, while in other theropods they can be very close together; in tyrannosauroids they outright touch the sacral vertebrae.
Not that much. Aerosteon lifts the middle part of its tail too high, and the tail of Majungasaurus is simply smaller than in the fossils.
John H., never get in the way of a good arbitrary line. Where would we be without them in palaeontology? Waddle - not waddle. New species - conspecific. Foramina - foramen. And on, and on, and on....
Righto Dave, they sure do make for good headlines and arguments! ;)
that skeleton still looks positioned rather oddly... I think maybe the legs are too straight and the body isn't quite horizontal enough... I'm not sure, it just looks a little odd.
Tommy Tyrberg:
That's true, but there may still be differences in posture even among very closely related and anatomically similar taxa, as birdwatchers are well aware.
To take an example, true thrushes (of the genus Turdus) are neornithinine, perching birds that also spend a lot of time on the ground. When on the ground, one species, the blackbird (T. merula), typically has a more squat and horizontal body posture than the other European species. These hold their bodies slightly but visibly more erect, almost at a 45 degree angle. With some experience, you can quite confidently tell apart a blackbird from other European thrushes (including the similarly dark-coloured ring ouzel, T. torquatus) by its profile alone.
Perhaps there really is some morphological difference between Turdus merula and the other thrushes that causes them to have different body postures; I don't know. But if such a difference exists, it's likely very subtle. Something that probably could/would not be detected, were thrushes only known as fossils.
My point, insofar as I have one, is that reconstructing the postures of dinosaurs and other extinct animals may be more tricky than we'd like to admit...
Re: Theropod body posture...is it possible we've all suffered over-exposure to Mr.Paul's dynamic reconstructions? His standard figure is at speed, and the inclination of the body would be right for that, but I find it quite reasonable that when slowing down or stopping that the body should incline a few degrees, bringing the head up to look out for food, or to be food. Note the Roadrunner, or better, the Pheasant - that frantic horizontal posture it attains shortly before contact with your front bumper.....compared to its ludicrously stately progress when less excited.
To Jared...the photo (which I think should be creditted to David Lambert or NHM archives) of the NHM T-rex appears to have been taken in almost shadowless light, reducing the different angles of upper and lower leg. The knee is also slightly splayed to get round the gut, so seeming straighter from the photographer's viewpoint. But then there are some individuals who are of the opinion that large Theropod legs should be straighter and more massive than normally depicted, an argument which once more takes us back to Mr.Paul.
Jim
Which brings a question - would carnosaurs normally bend their neck and lift the head and how much? And what is angle of the head? I actually wondered also how well field of vision of such animal cover things under its feet (in reference to talk that if T-rex tripped it would die from fall).
Many birds feed when crunched forward, but they are able to bend legs in false knee and place feet forward, which carnosaurs couldn't do. BTW, mobility of leg joints of modern birds is incredible.
BTW - I find it incredible that there is about complete T-rex skeleton in Britain and nobody displays it. Besides everything it would be a goldmine for the museum.
There is currently a complete T. rex skeleton in Manchester Museum, which I have seen twice. Tis a cast of 'Stan'.
Alas poor tyrannosaurus, I knew him well.
In the bottom left of the lower picture you can make out what was quite an impressive trackway. I seem to remember that there was no sign of tail drag, as you would expect from the above comments.
I also seem to remember a spokesman for the museum saying on TV at the time that the exhibit was to be dismantled because it was only a half skeleton.
The Oxford University Museum of Natural History also has a complete Tyrannosaurus cast.
Hi Darren.
This is a classic picture from my Childhood, even though I've never been to London.
I also need to ask you a small question, can you email me when you have time?
Just saw the new T. rex mounts at the Carnegie Museum yesterday on the way to Cleveland: now THOSE are some seriously good mounts!!
By the way, hi from SVP!
Yeah, thanks Tom.
:)
The neck is S-shaped in almost all theropods. Reconstructing it as straight requires disarticulating it.
(And as I'm sure you know, Tyrannosaurus was taken out of Carnosauria in 1992.)
Re: Waddle
It all depends on speed. When moving slowly animals shift their weight to maintain the center of gravity. The faster you move the less shift is required. Try it. Walk very slowly and gradually increase your speed until you are going as fast as you can.