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Post by Infinity Blade on Apr 8, 2014 5:21:24 GMT 5
I've heard champsosaurs could bite significantly harder than gharials, despite their similar jaw morphology, owing to the huge muscles in the former's temporal fenestrae. carnivoraforum.com/single/?p=8224662&t=9333464^According to this, Champsosaurus natator had a stronger bite than a gharial's by ~62% (1910N vs. 1182N) www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0031781^According to this though, the mean molariform bite force for the Indian gharial was 1895N, not anywhere near significantly harder (hell, not even 1% harder). I'm confused. What do I believe? Are there higher figures for the champsosaur's bite? I do suspect Champsosaurus et al. to be able to bite harder given their giant temporal fenestrae, though I'm not sure if that alone is enough for a more powerful bite............ |
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Post by creature386 on Apr 8, 2014 19:08:24 GMT 5
Maybe this are again some bite force measurements at different jaw spots. I am not bite force expert though, the high variation of numbers has confused me since quite a long time.
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Post by theropod on Apr 8, 2014 20:47:48 GMT 5
Are’t indian gharials significantly larger than Champsosaurus?
Gavialis gangeticus was represented by a mean total lenght of 3.26m, afaik only Champsosaurus gigas can attain that size, which means comparing these values isn’t representative of relative bite forces.
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Post by Infinity Blade on Apr 9, 2014 0:12:16 GMT 5
Large gharials are significantly larger than even Champsosaurus gigas, if Wikipedia is to be believed.
I guess it's possible they're referencing different jaw points as creature suggests, but they don't seem to give any clue on that.
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Post by creature386 on Apr 9, 2014 0:27:05 GMT 5
Different specimen size, another problem we need to consider.
I have to take back my statement about jaw spot, they gave a bite force range and I guess the upper end was at the highest spot. Unfortunately, it is just an abstract, we have no materials and methods section, to look up the used specimen and its size.
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Post by theropod on Apr 9, 2014 1:29:18 GMT 5
It’s conceivable the champsosaur and the gharial in that paper were closer in size than the champsosaurus was compared to the gharial in the Erickson et al. study.
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Post by Infinity Blade on Apr 9, 2014 6:31:15 GMT 5
Champsosaurus in Erickson et al.?
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Post by creature386 on Apr 9, 2014 21:57:05 GMT 5
There is no Champsosaurus in that Erickson et al. Theropod probably compared the gavial there with the Champsosaurus in the abstract.
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Post by theropod on Apr 10, 2014 0:58:09 GMT 5
I kind of messed up my sentence, there wasn’t supposed to be any Chamsosaurus in that study.
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Post by Infinity Blade on Apr 10, 2014 2:13:13 GMT 5
Alright then, cause I found no Champsosaurus in that study.
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blaze
Paleo-artist 
Posts: 766
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Post by blaze on Apr 10, 2014 2:25:18 GMT 5
The difference in the values provided in James (2009) abstract and Erickson et al. (2012) for the gharial is not only that James used the "dry skull method" which is known to underestimate biteforce compared to in vivo measurements but also that the forces given in James abstract are not biteforces but the forces produced by the jaw abductor muscles. I found his thesis, he doesn't mention the actual lengths of the skulls he used, they were scaled to the same orbito-dorsocranial length and the resulting total length are the only ones he gives, that of the adult C. natator ended up at 41.5cm long while that of the gharial ended up at 50.7cm, this means that the gharial had a 22% longer snout. At the same ODCL the adult Champsosaurus skull produced jaw muscles forces 6% greater than the gharial (2352N vs 2211N) and comparing this with those reported in the abstract I think we can estimate the actual lengths of their skulls. He also provides bite forces at several gape angles, at 25° the adult Champsosaurus bites with about 80% greater force than the gharial but I'm not sure if this bite forces are still at the same ODCL or are scaled to the actual size of their skulls, something else weird about them is that if I'm reading the tables right the biteforce is greater the further away from the jaw joint, shouldn't it be the other way around? You can check for yourselves here. |
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Post by creature386 on Apr 10, 2014 13:39:16 GMT 5
The link is broken, thanks for your explanation nonetheless.
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blaze
Paleo-artist
Posts: 766
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Post by blaze on Apr 10, 2014 23:16:33 GMT 5
It works for me but I changed it. Does it work now?
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Post by creature386 on Apr 10, 2014 23:34:50 GMT 5
"500 Internal Server Error
The server encountered an unexpected condition which prevented it from fulfilling the request.
If you have any question or comment, please contact your system administrator."
Maybe that's just on my computer.
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blaze
Paleo-artist
Posts: 766
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Post by blaze on Apr 11, 2014 0:05:02 GMT 5
That error message implies is not something to do with your computer but rather the site itself... which is weird since I'm not having those problems
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