An injured Allosaurus?

A few years ago I spotted this Allosaurus on display in Japan. As you can see, there appears to be a dent in the scapula surrounded by a ridge of bone. This too me looks suspiciously like a pathology of some kind but the skeleton on display is a cast and I don’t know what specimen it’s based on. I’ve had a quick flick through the literature and while there have been papers on Allosaurus pathologies I’ve not seen anything on the shoulder brought up before.

So this post is kinda two pronged – first off: cool an Allosaur pathology! And two, if you’ve seen this exact one before, can you point me to the specimen number or even a paper describing it?

18 Responses to “An injured Allosaurus?”


  1. 1 Jay 23/04/2011 at 2:05 pm

    Or is it a ‘feature’ arising from a mistake in either molding or casting work?

    • 2 David Hone 23/04/2011 at 3:21 pm

      I really don’t think so. The scap is such a simple element and the case was otherwise perfect. And it did look like some other pathologies I’ve seen before. I think it’s a genuine feature.

  2. 3 T. MIZUKAMI 23/04/2011 at 2:15 pm

    I think it’s a following paper.

    http://en.wikipedia.org/wiki/Allosaurus
    References No.96

    Goodchild Drake, Brandon (2004). “A new specimen of Allosaurus from north-central Wyoming”. Journal of Vertebrate Paleontology 24 (3, Suppl.): 65A.

  3. 5 Tim Donovan 23/04/2011 at 3:55 pm

    What might’ve caused that? Bite from another Allosaurus? Blow from a sauropod manual claw? Or stego spike? The location may not seem right for the latter.

    • 6 David Hone 23/04/2011 at 4:13 pm

      Well I’d generally say that few big predators get injured by their prey, so while anything’s possible it wouldn’t be high on my list and as you note, the position makes it generally unlikely too. A bite also seems odd as it seems to be a ‘point’ effect whereas a decent bite from another allosaur that reaches the bone should make quite a mark over an area. My suspician is that it’s just some random injury (it fell over, or scratched itself on a tree or whatever) that got infected and thus left a rather big and ugly mark. Though obviously that’s little more than a best guess.

      • 7 Albertonykus 25/04/2011 at 2:57 am

        Although there is an Allosaurus specimen known with a stegosaur puncture wound. It’s on the tail vertebrae though, not the scapula. (Original reference is Carpenter, Kenneth; Sanders, Frank; McWhinney, Lorrie A.; and Wood, Lowell (2005). “Evidence for predator-prey relationships: Examples for Allosaurus and Stegosaurus”.)

  4. 8 Darren Naish 23/04/2011 at 10:39 pm

    The _Allosaurus_ on display at Denver (the one mounted as if attacking a _Stegosaurus_: you can see photos of it all over the net) has very similar holes in its scapulae. I recall hearing that they’re actually damaged caused by bolts previously used to hold the scapulae in place. Could be the same thing – certainly looks similar.

    • 9 David Hone 24/04/2011 at 9:05 am

      That would be odd. I can imagine the hole being a bolt like that, but not the thickening around it. Even if that was say a poor repair job, why not fix it in the mould or the resultant cast? This gets more and more strange.

  5. 11 brian engh 25/04/2011 at 7:24 am

    “I’d generally say that few big predators get injured by their prey”

    Really? Predation is pretty full contact…

    baboon bites croc:

    Sea turtle biting the gills of an attacking tiger shark:
    http://www.metacafe.com/watch/1070627/turtle_v_shark_dont_mess_with_this_turtle/

    Lion skewered by buffalo:

    Sperm whele with extensive scarring from squid:
    http://dsc.discovery.com/convergence/blueplanet/alert/slideshows/gallery/slide_squid04.jpg

    Oh… you mean BIG predators!:

    I had waaay too much fun finding these images… Anyway, in the few years us humans have been observing modern predators (many of which have much more developed brains than mesozoic theropods) we’ve seen an awful lot of predators getting injured or even killed by their prey. It would seem to me that in the millions of years that Allosaurs were around there would’ve had to have been times when they did dumb stuff and got wrecked by stegosaurs and and sauropods and even camptosaurs. They were all extremely powerful animals, and none of them appear to have been exceptionally intelligent.

    How big is the allosaur with the pathology? aren’t average sized Allosaur shoulders right around stegosaur tail-strike height? Just imagine an Allo trying to bite the haunches of a fleeing stegosaur – wouldn’t it’s shoulders and ribs be moving around in the likely stegosaur tail-strike zone? I mean prey doesn’t usually just let a predator walk up and bit them in the face… seems like most attacks with modern animals start from the rear.

    Here’s a picture of that awesome mount in Denver that Darren mentioned. notice how the stegosaurs tail spikes float right around the Allosaur’s shoulder height…

    http://cdn.wn.com/pd/b3/08/7125ceb5b96333139dd5c22cebf5_grande.jpg

    • 12 David Hone 25/04/2011 at 9:16 am

      Yes obviously predators do get injured by their prey, but it’s not like it’s on a daily basis. If it were, there’d soon be no predators out there. Remember, a mammalian predator needs to hunt even big prey every few days. If it has even say a 1 in 100 chance of picking up a serious injury (i.e. the kind I’m talking about here) then on average this would happen every year to every predator and it would pick up half a dozen or more in a lifetime. That just doesnt happen – you don’t see skeletons covered in pathologies or every lion or hyena with a set of massive scars or whatever.

      Therefore while these things do happen, it’s probably not the most likely interpretation for the Allosaur injury.

      “Just imagine an Allo trying to bite the haunches of a fleeing stegosaur – wouldn’t it’s shoulders and ribs be moving around in the likely stegosaur tail-strike zone? ”

      Maybe, but it’s a rather high. And with something as powerful as a setgosaur tail I’d expect a direct hit to break a bone like a scapula, not just leave a dent.

      “How big is the allosaur with the pathology? aren’t average sized Allosaur shoulders right around stegosaur tail-strike height?”

      And that makes the huge assumption that they would ever tackle and adult stegosaur which I don’t think they would. OR again that it would be really rare, *becuase* of the danger posed. So we have an unlikely event (attacking a dangerous adult) coupled with an unlikely even (the allosaur got hit) coupled with an unlikely outcome (the strike was jsut powerful enough to graze the bone, but not actually break it, and across the top of the shoulder). Put it togehter and yeah, it’s all still possible, but I don’t think it’s likely, which is the key here.

  6. 13 Tim Donovan 28/04/2011 at 2:06 pm

    “Just imagine an Allo trying to bite the haunches of a fleeing stegosaur…”

    The raison d’etre of a thagomozer, and some armor, was to enable a stego to hold its ground.

    “And that makes the huge assumption that they would ever tackle and adult stegosaur which I don’t think they would. OR again it would be really rare..”

    It was probably rare but it definitely happened.

  7. 14 brian engh 03/05/2011 at 12:57 am

    good points all around – especially about the stegosaur tail breaking a scapula… those big long spikes would’ve no doubt had some serious penetrating power.

    get it? good ‘points’… sorry, i couldn’t resist.

    “The raison d’etre of a thagomozer, and some armor, was to enable a stego to hold its ground.”

    Is it? I can think of quite a few modern animals with spikey tail defenses and/or armor that will first attempt to run from a predator before employing their spikes as a last defense… I’m thinking uromastyx, girdled lizards, spiny tailed iguanas, hedge hogs, porcupines – even armadillos will try to run first. I know these aren’t the best analogues for stegosaurs but being that I can’t really think of a living animal that doesnt run before using it’s close combat defenses, I just can’t imagine a stegosaur standing and waiting for an approaching theropod to get close enough that they have to out-maneuver it well enough to use their tails on them.

    Oh wait! i thought of one! – skunks tend to hold their ground, even against cars and trucks (which destroy them all the time where i live).

  8. 15 Tim Donovan 03/05/2011 at 12:16 pm

    “I know these aren’t the best analogues for stegosaurs..”

    Lol, small lizards and mammals are FAR from it.

    “..that they have to out-maneuver it well enough….”

    Which is precisely what stegosaurs were adapted to do. Read what Bakker wrote about their deltopectoral crest. We know stegosaurs fought with theropods, suffering as well as inflicting injuries.

  9. 16 Kenneth Carpenter, Ph.D. 20/10/2011 at 11:36 pm

    Greetings all. The mystery of the pathology is that the specimen was from the Cleveland-Lloyd Dinosaur Quarry (there are two with similar pathologies, casts of both mounted on the Denver Allosaurus – left and right). Both have been thin-sectioned. Lorrie McWhinney (Denver) was supposed to describe the specimen for the Carnivorous Dinosaurs volume, but never did. The ring of bone is real and is not quite the same on both scapula. They are not punctures because the thin-sections show that the growth is on the surface of the bone, and that it is surface bone seen on the inside of the pathologies. Therefore, they are not puncture wounds. Rothschild has described them as muscle avulsion scars, but that cannot be since the muscles in question are long and cover most of the lateral surface. He mistakenly thought the muscle inserted at the pathologies by a tendinous process that was pulled from the bone (see the descriptions of the humerus of “Sue”). Best Lorrie could conclude was that they are of an unknown etiology that triggered a reactive bone process i.e., something (disease, parasite, cyst, etc.,) irritated the surface of the bone causing it to produce the bone in defense. Beyond that becomes unsupported speculation (in her mind).

    Ken


  1. 1 Jane’s pathology « Dave Hone's Archosaur Musings Trackback on 15/01/2012 at 11:24 am

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