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Post by theropod on Feb 3, 2014 18:09:05 GMT 5
Actually, that means it would be smaller, since it would suggest a proportionally bigger skull, the skull being the part we have for comparison.
That is really an extreme difference in Aegisuchus. How did they get estimates for a total skull lenght of at least 2m based on regression analysis of the braincase size? It seems unbelievable that such a small braincase would hold the largest brain of any Crocodilian...
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Post by Runic on Feb 3, 2014 18:17:44 GMT 5
Actually, that means it would be smaller, since it would suggest a proportionally bigger skull, the skull being the part we have for comparison. That is really an extreme difference in Aegisuchus. How did they get estimates for a total skull lenght of at least 2m based on regression analysis of the braincase size? It seems unbelievable that such a small braincase would hold the largest brain of any Crocodilian... How? It said of comparable length, which is the main part I was referring to. If they are more robust and heavier at comparable lengths along with a much larger skull that doesn't offset the entire scaling process?
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Fragillimus335
Member
Sauropod fanatic, and dinosaur specialist
Posts: 573
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Post by Fragillimus335 on Feb 3, 2014 22:06:08 GMT 5
Actually, that means it would be smaller, since it would suggest a proportionally bigger skull, the skull being the part we have for comparison. That is really an extreme difference in Aegisuchus. How did they get estimates for a total skull lenght of at least 2m based on regression analysis of the braincase size? It seems unbelievable that such a small braincase would hold the largest brain of any Crocodilian... How? It said of comparable length, which is the main part I was referring to. If they are more robust and heavier at comparable lengths along with a much larger skull that doesn't offset the entire scaling process? What he means is that if we assume Black Caimans have larger heads than other crocs then the body would be proportionally smaller at equal skull lengths.
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blaze
Paleo-artist
Posts: 766
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Post by blaze on Feb 3, 2014 22:09:25 GMT 5
That might be an extreme example though but it appears all modern alligatoroids are like that, Woodward et al. (1995) found that in the American alligator the head gets proportionally bigger with body size, the opposite appears to be the case in crocodilids, for example the biggest American alligator skull is 64cm long, and it's estimated to have come from an individual around 4.5m long, for comparison, the skull of lolong is "only" 70cm long, though it is important to highlight that tail length might be skewing the comparisons, American alligators have tails less than 49% of their total length while at least in the case of lolong, 54% of its total length is tail, if lolong had the same tail length proportions as American alligators it would have been only 5.5m long. It does affect the scaling and that's why all recent estimates of total length are done using equations derived from the American alligator. theropodI know... could you check it's size too? since my results are several times smaller than what the paper got one could think that I have to be the one that made a mistake so I'd like to see what other people get.
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Post by theropod on Feb 3, 2014 22:51:42 GMT 5
@bi you wrote "I wonder if Purrusaurus was built similar like a Black Caiman, if so it should be the biggest." No lenght parity. they simply wouldn’t be if one had a considerably larger skull relative to its body size. blaze: I’ll check, but to your scaling appears to be correct.
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Post by Runic on Feb 3, 2014 23:11:39 GMT 5
@bi you wrote "I wonder if Purrusaurus was built similar like a Black Caiman, if so it should be the biggest." No lenght parity. they simply wouldn’t be if one had a considerably larger skull relative to its body size. blaze: I’ll check, but to your scaling appears to be correct. Um what else does "built like" mean to you? If I recall I wasn't specifying the head proportions. By me saying "built like" it should have been obvious mean body proportions.
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Post by Life on Feb 4, 2014 0:28:48 GMT 5
Purrusaurus appears to be heavily built and very long as well. It does looks massive in comparison to other crocodilians due to its heavy built, not the longest but possibly most massive crocodilian among the well-known gigantic rivals, IMO.
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Post by theropod on Feb 4, 2014 1:20:25 GMT 5
Um what else does "built like" mean to you? If I recall I wasn't specifying the head proportions. By me saying "built like" it should have been obvious mean body proportions. "Built like" to me implies similar proportions. If it was built like a caiman, and caimans really have proportionally bigger heads, then that would make its body smaller, not larger Hence, there simply would be no lenght parity, considering their skulls are all similar in lenght ( Purrussaurus being the shortest by a small margin, but not significantly). If it was stockier, that does not imply greater body mass if in exchange it was simply shorter. So how exactly does that make it the biggest, when it means the exact opposite?
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Post by Runic on Feb 4, 2014 1:40:49 GMT 5
Um what else does "built like" mean to you? If I recall I wasn't specifying the head proportions. By me saying "built like" it should have been obvious mean body proportions. "Built like" to me implies similar proportions. If it was built like a caiman, and caimans really have proportionally bigger heads, then that would make its body smaller, not larger Hence, there simply would be no lenght parity, considering their skulls are all similar in lenght ( Purrussaurus being the shortest by a small margin, but not significantly). If it was stockier, that does not imply greater body mass if in exchange it was simply shorter. So how exactly does that make it the biggest, when it means the exact opposite? Sigh theropod, pay attention to the "more robust " and "comparable lengths" part of the quote that I posted when talking about body proportions. By "biggest" hence I said IF it was by merely using the "similar lengths" part of the quote.
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blaze
Paleo-artist
Posts: 766
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Post by blaze on Feb 4, 2014 3:42:18 GMT 5
It depends on what exactly makes the black caiman be "relatively more robust", if robust is defined as total length/weight then it could be a deceiving metric, for example a caiman 2m in svl could be only as robust as a 2m svl croc but if the croc has a longer tail and its total length is 4.4m instead of the 3.9m of the caiman then the caiman will appear to be more robust.
More on topic (or not) I don't know if it can be appreciated at that scale, but anyone sees the similarities between the skulls of Aeigisuchus and Purussaurus? and that of the black caiman too is very similar.
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Post by Vodmeister on Feb 4, 2014 20:07:22 GMT 5
Rhamphosuchus?
The largest estimates done by researchers have the animal at 15-18 m (50-60 ft).
Heilprin, Angelo (1974). The Geographical and Geological Distribution of Animals.
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Post by theropod on Feb 4, 2014 20:33:46 GMT 5
Black Ice, do I really need to explain the meaning of your own posts to you? It is absolutely clear to everyone what that quote implies (and what it doesn’t imply), that at the same lenght a black caiman has a larger head and is apparently generally mroe robust, i.e. heavier, what you wrote however is in contradiction with it (I don’t think I need to quote it again), and that’s what I replied to. That is, unless you manage to tell me how exactly you implied anything else than "In that case, it would be the biggest" with the underlined part. blaze: Indeed, the general shape is similar, in that it is smooth and rounded. There’s a huge disparity in the degree of elongation though. I wonder what those "duck-faced"-croc skulls evolved for... Vodmeister: The same has been said for Purussaurus, and later revised. More recent publications state much smaller sizes. I have not studied the description though, so I cannot say how well-justified either figure is.
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blaze
Paleo-artist
Posts: 766
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Post by blaze on Feb 4, 2014 21:16:59 GMT 5
VodmeisterThose were based on pieces of rostrum, more accurate estimates of 8-11m were done after the discovery of the first complete skull in 2000. (Head 2001), this was mentioned in a conference abstract, it seems it hasn't been published yet.
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Post by Vodmeister on Feb 4, 2014 22:32:42 GMT 5
In that case I'm leaning towards Deinosuchus.
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Post by Infinity Blade on Feb 5, 2014 1:27:56 GMT 5
I think Deinosuchus riograndensis, Purussaurus spp., and Sarcosuchus spp. should all be roughly tied. Edit: I almost forgot, what about Crocodylus bugtiensis (clickable)? I've heard 10-11m for that thing, is it true? A giant crocodile species that preyed on Paraceratherium sounds awesome and should be up there with the three I mentioned.
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