Sauropod Jaws

While there is obviously some variation in the teeth and jaws of sauropods, they are on the whole pretty conservative when compared to the theropods or ornithischians (none of them have beaks for starters!). Rather peg-like clippers of one form or another seem to be the main theme. This nice set of jaw piece though does show that if nothing else, the size and number of the teeth can be dramatically different across a jaw of otherwise similar size.


Here we have the multiple and very small teeth of Nigersaurus (top), rather more robust, but still ultimately long, thin and quite numerous teeth of Apatosaurus (middle), and finally the much larger and more robust teeth of Camarasaurus (bottom). Nigersaurus is especially nice and odd as you can see the huge numbers of replacement teeth sitting in situ the gives this an appearance that’s something like a dental battery of a derived ornithischian.


8 Responses to “Sauropod Jaws”

  1. 1 David 26/08/2011 at 11:22 am

    What about Bonitasaura?

    • 2 David Hone 26/08/2011 at 11:31 am

      I’d missed that completely. There’s always an exception you don’t know about. I stand corrected (though it doesn’t really affect my point I don’t think).

  2. 3 DF 26/08/2011 at 8:30 pm

    A niggle that always annoys me: batteries!

    A “battery” is where multiple rows of teeth (or guns) operate at the same time, hence a hadrosaur has a dental battery (usually 3 rows on the dentary). Nigersaurus has a row of teeth that operate and wear down individually, and are replaced individually, as is seen in all sauropods, most theropods, and various ornithischians. Hence, Nigersaurus doesn’t have a dental battery any more than T. rex does. It does have reduced tooth size and rapid replacement, but that isn’t a battery.

    I don’t know why this has never been picked up by reviewers of the various Nigersaurus manuscripts.

  3. 5 Mark Robinson 27/08/2011 at 4:18 am

    The Apatosaurus pic is interesting. The more anterior teeth appear to show that every second tooth is “on duty” with the others in reserve. Do we know whether their teeth were likely to have been continually replaced throughout an individual’s life or whether there is some limit on how many teeth they get?

  4. 6 Jim Kirkland 01/09/2011 at 2:58 pm

    We just found a dentary for our new sauropod skeleton from base of Cedar Mt. Fm.; very Camarasaur-like.

    Oh; and I look at Apatosaurus and kin as having a dental battery as in cross-section 3 teeth are coming in per file; for mutual support and alternating function.

    • 7 DF 01/09/2011 at 3:37 pm

      I agree that when you look at a section of a diplodocoid aveolus, mutliple replacement teeth are visible stacked up behind the first tooth, and these may provide some support. However, I am not aware of a study on sauropods that shows wear facets on the first tooth and subsequent replacements within the same alveolus: ie. they have not been shown to be wearing at the same time. This is the requirement of a battery.

      Rebbachisaurs (and to a lesser extent, all diplodocoids) have a derived, rapid-replacement system (smaller teeth, more replacments ready), that maintains a more even tooth row more consistently than other sauropods (and dinosaurs in general), but it is more akin to a self-replacing beak (for snipping), than a battery (for grinding).

  1. 1 Dental batteries « Dave Hone's Archosaur Musings Trackback on 09/09/2011 at 3:25 pm
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