Link to PDF:

Wedel, M.J. 2012. A monument of inefficiency: the presumed course of the recurrent laryngeal nerve in sauropod dinosaurs. Acta Palaeontologica Polonica 57(2):251-256.

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Figures:

Wedel (2012) Fig. 1. Course of the left vagus nerve and left recurrent laryngeal nerve in a human, a giraffe, and Supersaurus. The right recurrent laryngeal nerve passes caudal to the right subclavian artery rather than the aorta and ductus arteriosus, but otherwise its course is identical to that of the left.

Wedel (2012) Fig. 2. The longest cells in the bodies of sauropods were sensory neurons that connected receptors in the skin of the extremities with interneurons in the brainstem, a pattern of neural architecture that is present in all extant vertebrates. The nerve cell bodies would have been located in the dorsal root ganglia adjacent to the spinal cord. The diagram of the neuron is based on Butler and Hodos (1996: fig. 2–1B).

9 Responses to “Wedel (2012) on long nerves of sauropods”

  1. Adam Baig Says:

    I can see that a diplodocid would need such a long nerve to ensure that an effective whiplash against an attacking theropod would register in its brain.

  2. Matt Wedel Says:

    I can see that a diplodocid would need such a long nerve to ensure that an effective whiplash against an attacking theropod would register in its brain.

    Maybe. The point is that all vertebrates have these nerve paths from brainstem to tail, whether they use their tails for whomping things or not. Diplodocids are not special in this regard.

  3. Adam Baig Says:

    Hi Dr. Wedel,

    Though I may have said my comment as something special, it was meant to be just a general comment. However, thanks. It was nice of you to reply.

  4. Jeroen Vanhaute Says:

    Hello Dr. Wedel,

    I stumbled across this great blog when I looked up some reactions on the ‘clash of the dinosaurs’ series. I am just a young economist (the despised marketeer kind), but I have been fascinated by history and dinosaurs since I was a kid, as no doubt many here are.

    When I get the chance to catch a documentary that seems interesting, I make sure I free up some time to watch it in time. However, this last one (CotD) seemed laughable, even to me as a layman. So I thought I’d check out some online reactions on the series, and I’m relieved to see a doctor in Palaeontology distances himself from much of the ‘scientific material’ shown. I was already thinking the majority of palaeontologists are sensation-crazy and look for the most absurd and spectacular traits in dinosaurs (infrasound blasts from Hadrosaurs? Is this pokemon?) to get some press. Fortunately, my respect has been restored by spending the evening reading this blog, which by the way is very entertaining, despite the boring science.

    So, sorry for stalling, but I have no palaeontologist acquaintances and I’ve been asking myself a couple of questions regarding your profession. I hope none of them are offensive, I’m sorry if they are.

    Firstly: I realize that in every scientific branch there are those who take their work seriously, and who seek recognition through it, and those who just want attention. But from what I’ve seen in documentaries, it seems like quite a lot of experts assume a great deal and hold it for truth while it just seems absurd to me. Is this just a misinterpretation from me, or are most documentaries just distorted representations of genuinely professional experts to maximize the number of viewers?

    Secondly: is it not possible that some vague discoveries of extreme species (such as the Amphicoelias) are simply bones of an overgrown but already discovered species? The world’s biggest man was almost 3 metres tall, and I’m sure that if his remnants would be discovered, some people would think he wasn’t part of the homo sapiens group.

    And finally: Do you have any good books, articles, documentaries or whatever to recommend for a layman with a passion for any kind of history and biology? And if possible, the same to donate as a present for adults?

    I completely understand if you didn’t read any of this, or won’t bother to reply. But it would make me as happy as a kid if you did.

    All the best and with great respect,

    Jeroen Vanhaute from Belgium

  5. Mike Taylor Says:

    Hi, Jerome, good to hear from you.

    I realize that in every scientific branch there are those who take their work seriously, and who seek recognition through it, and those who just want attention. But from what I’ve seen in documentaries, it seems like quite a lot of experts assume a great deal and hold it for truth while it just seems absurd to me. Is this just a misinterpretation from me, or are most documentaries just distorted representations of genuinely professional experts to maximize the number of viewers?

    Mostly the latter. Almost without exception, palaeontologists are very careful to express the level of uncertainty surrounding their work (in fact you’ll find recent posts on this blog that are about nothing but this!) We know that the people making Clash of the Dinosaurs edited Matt misleadingly, and I am sure they did the same to others.

    Is it not possible that some vague discoveries of extreme species (such as the Amphicoelias) are simply bones of an overgrown but already discovered species?

    Yes. If only we had good enough fossils to determine this either way with confidence! There are some well established examples of this happening, though Seismosaurus, has been independently found by two groups to be a large Diplodocus.

    Do you have any good books, articles, documentaries or whatever to recommend for a layman with a passion for any kind of history and biology? And if possible, the same to donate as a present for adults?

    I only know about dinosaur books. Among those, Bakker’s The Dinosaur Heresies is still among the best for telling a coherent scientific stories, even if 25 years after publication many of the “heresies” are now orthodox and some of the others have been discarded. It’s a good book for drawing people into the science. Holtz and Rey’s Encyclopedia, though nominally aimed at older kids, is actually full of excellent and up to date infromation for adults, too, and is absurdly good value. If you want to go a bit deeper, Farlow and Brett Surman’s The Complete Dinosaur is a collection of articles containing excellent introductions to different aspects of dinosaur science, including physiology, biomechanics, phylogenetics, etc. — but you may want to wait for the 2nd edition which should be along soonish. Finally, The Dinosauria, edited by Weishampel, Dodson and Osmolska is currently the “go to” book for hardcore information about the different dinosaur groups.

    Hope this helps.

  6. Jeroen Vanhaute Says:

    Hello Mike,

    Thanks for the swift reply! I’m happy to understand that palaeontologists realize there always is a factor of uncertainty and are careful with their assumptions. Your example of the Seismosaurus (I remember reading about that now that you mention it) proves nothing is taken for granted.

    Thanks a lot for the recommendations, I’ll definitely look into those works. I especially look forward to that second edition of ‘The Complete Dinosaur’ you mentioned.

    I read you were a programmer in the first place, and an amateur palaeontologist in the second, but I a hobby is often a person’s real passion. So best of luck with all of your work, and I hope you’ll be able to discover many more species and bring new interesting aspect about dinosaurs to light. What a great website you’ve developed as well, thanks!

    Kind regards,

    Jeroen (not Jerome, but it’s basically just the Dutch version of Jeroen – Belgians are a weird and mixed species of all nations surrounding us :) )

  7. Mike Taylor Says:

    Oops, MANY apologies for getting your name wrong when it was right there on the screen in front of me. And thanks for your kind words.


  8. Hi,
    in this paper (Wedel, M.J. 2012. A monument of inefficiency) right before the conclusion there’s interesting discussion of axoplasmic transport speeds, high and low. I had never thought about this before.
    It seems to me now that even for a giraffe (let alone sauropods or whales) ordinary observed flow rates would be problematic – if not augmented or addressed by other means.
    At the quoted speeds (for some proteins) of only 0.1-1.0mm/day, a distance from midpoint cell body to either cell tip (=brain to extremity distance, halved) of say 2m in a giraffe would imply 2000-200 days transport time!
    Also, as with sauropods, I would imagine that giraffes’ necks (and parts of many other animals) must be growing in length at above that rate for some part of their life, so how do these cell tips continuously acquire all they need? The answers could helpfully throw light on the sauropod issue, as indeed the paper indicated.


  9. It’s worse, I did my math wrong! It should be 20,000-2,000 days transport time! (I doubt any giraffe has lived 20,000 days…)


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