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.