Apex
Junior Member
Posts: 207
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Post by Apex on Jan 14, 2016 3:04:10 GMT 5
Not fully relevant but does anyone have any info on Machimosaurus or Smilosuchus and how big they were?
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Post by theropod on Jan 14, 2016 3:47:16 GMT 5
There’s this: www.sciencedirect.com/science/article/pii/S0195667115301178The skull of Machimosaurus rex is estimated at 1.6m and total length at 10m. The paper is very recent (only the abstract is available as of now), but the material doesn’t seem too fragmentary from the skeletal. M. hugii is also very large, there’s a skull estimated to approach 1.5m, suggesting individuals exceeding 9m: rsos.royalsocietypublishing.org/content/royopensci/1/2/140222.full.pdfThese are the size estimates from the paper: species references basicranial length (cm) body length estimate (m)
M. hugii [6,7] 149 9.26
M. mosae [62] 130 8.08
M. buffetauti [3] 100 6.22
[10] 93.5 5.81
"Table 4. Estimated total body lengths for Machimosaurus specimens. Estimate based on the ratio of the basicranial length (96.5 cm) to total body length (approx. 600 cm) of the M. mosae neotype [4,21]." |
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Apex
Junior Member
Posts: 207
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Post by Apex on Jan 14, 2016 4:22:14 GMT 5
Thanks theropod, I had heard rumours but I thought it was all media hype
Hopefully it doesn't get significantly downsized like every other aquatic carnivore has been
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blaze
Paleo-artist 
Posts: 766
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Post by blaze on Jan 14, 2016 8:24:58 GMT 5
I highly doubt it, it's based on an almost complete skeleton of another Machimosaurus species and the skull of M. rex itself is fairly complete.
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Post by Grey on Feb 6, 2016 18:52:30 GMT 5
I've consulted McHenry's work again and performed some complementary calculations.
Regarding the NHM symphysis, for some reason he gave TL estimates based on Liopleurodon and Simolestes but not on the NHM R39362 Pliosaurus macromerus specimen. Anyway, based on symphysis width it suggests a TL very similar to the Liopleurodon-based estimate, 15.07 meters.
Alternatively, still unsure about the statement that pliosaurids should be regarded with a skull-body ratio of 1:6, I've nevertheless used that potential proportion to give another potentia sizes for some of the specimens in McHenry's thesis. Based on this ratio for example, the Cumnor Monster would have been 15 meters long.
Using this ratio on the largest Liopleurodon described by Andrew and adjusting the vertebra of the Peterborough potential pliosaur and the Monster of Aramberri with the closest vertebral positions in the Liopleurodon specimen, I got the following results (so, assuming this Liopleurodon was 7.56 m long, contra 6.39 m).
A 1 : 6 ratio would suggest for the Peterborough potential pliosaur a size of 15.9 meters (either by vertebral width and height) and 17.28 meters by vertebral length. The vertebra is assigned as c5 by McHenry, I compared it with the c4 in the Liopleurodon.
In Aramberri, the largest vertebra is d1, therefore I compare it with the 17th cervical in the Liopleurodon. Assuming the 1 : 6 ratio, Aramberri would be 11.81 meters using width, 15.12 meters using height and 15.87 meters using vertebral lenght.
Tentatively, I compare it with the 23th pectoral in the Liopleurodon. Still assuming the same ratio, vertebral width suggests 12.1 meters, height suggests 14.46 meters and length suggests 15.56 meters.
Also, comparing the NHM symphysis with the symphysis measurements in the Liopleurodon (and assuming the 1 : 6 ratio) suggests, by symphysis length a 10.65 meters pliosaur, by width a 14.45 meters animal. Strangely a bit lower than the Liopleurodon-based estimate of 15.1 meters by McHenry, maybe because of the difference in the symphysis proportions in the two Liopleurodon. Using the 15.1 m estimate from McHenry and applying the 1 : 6 ratio, this makes the upper size for the NHM symphysis at 17.8 meters.
But again the validity of such a ratio needs to be determined... Given McHenry's amount of works on this, I tend to still favor his results.
Nevertheless, the NHM symphysis seems indeed to represent the biggest hypothetical mega-pliosaur.
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Post by theropod on Feb 7, 2016 0:36:28 GMT 5
Is there a photograph/drawing or any other sort of documentation of that specimen available?
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Post by Grey on Feb 7, 2016 16:48:46 GMT 5
I've asked to McHenry to send me a picture of it but no response yet.
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Post by Grey on Apr 1, 2016 6:28:13 GMT 5
Aurajo et al. made some remarks in paedomorphism in large plesiosaurs and are of the opinion of adults retaining juvenile osteology.
file:///C:/Users/BMB%20INFORMATIQUE/Downloads/Ara%C3%BAjo%20et%20al%202015%20paedomorphism.pdf
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Post by Grey on Aug 6, 2016 5:07:21 GMT 5
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Deleted
Deleted Member
Posts: 0
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Post by Deleted on Aug 6, 2016 19:24:53 GMT 5
Lol, his logic is that since the specimens we have are probably not the largest ones out there, means we must take 19+ meter pliosaurs (which are upper-bound estimates) as minimum size. He also seems to think that freaking teeth are viable for use in estimating pliosaur size... |
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Post by Grey on Aug 7, 2016 0:33:48 GMT 5
Lol, his logic is that since the specimens we have are probably not the largest ones out there, means we must take 19+ meter pliosaurs (which are upper-bound estimates) as minimum size. He also seems to think that freaking teeth are viable for use in estimating pliosaur size... Is 19m even a realistic upper limit? We discussed this earlier with theropod, coherentsheaf and blaze. For sure using isolated teeth appears poorly reliable at best but I'm not even sure he does his homework properly, the 40cm tooth he refers is actually 35cm in straight line and has the same crown height than the other 22cm tooth he refers, suggesting the later had some of his root incomplete. I also think he uses a wrong skull/body ratio. Check his others articles, some are very funny. The sad thing is this guy is clearly enthusiastic and could give valuable points if he wasn't biased that much. |
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Post by coherentsheaf on Aug 9, 2016 0:29:53 GMT 5
Conservative would be to use ratios from Kronosaurus. I mean, a large head is more likely than a giant body. Of course one cannot completely rule everything out but, if you hear hoofs, think wildebeest. Wild horses are extinct.
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Post by Grey on Aug 14, 2016 20:18:25 GMT 5
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Apex
Junior Member
Posts: 207
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Post by Apex on Aug 29, 2016 23:34:59 GMT 5
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Post by Grey on Oct 29, 2016 4:08:38 GMT 5
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