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Post by theropod on Oct 22, 2014 2:27:01 GMT 5
Improved version: 4.6870m³ I’ve refined the mesh a bit, and changed the shape of the melon and spermaceti chamber to something slightly more physeteroid-like in the way commonly portrayed. This reduced the volume a bit, albeit to a neglegible degree. Of course this is still rough, I didn’t even model the teeth while other structures like the trachea are obviously included in the volume measurement. So this is probably not reliable within error margins of at least 0.1-0.2m³. And you we can only ballpark the mass based on this because estimating it would require precise knowledge of the relative sizes of various components. Attachments:
livcranium2.blend (810.64 KB)
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Post by theropod on Oct 25, 2014 3:36:57 GMT 5
a very strange observation: If restored following the pictures posted earlier, the soft-tissue outline at the base of the head will look like this, or have approximately this aspect ratio at any rate:  (over 2m wide but only about 1.5m deep) That means a very flat, wide shape for the whale’s body, given that like P. macrocephalus it does not deepen considerably behind the skull. Does any extant cetacean have such a shape? If we went by the Zygophyseter varolai (I retain that I think it’s a clear case of shrink-wrapping) reconstruction from its description, we’d get an animal even more extreme, i.e. over 1/3 wider than deep. I don’t know any whale built like that (even though there are extant and extinct cetaceans that also have flattened skulls–albeit possibly not to this extent–and in those it does coincide with a body deeper than the skull by a considerable margin), all that I know seem to be deeper than wide, or close to circular, but maybe someone can point out what I’m overlooking here. The alternative would be that the chest is actually deeper than the skull, like in this (perhaps reliable, perhaps not reliable) Brygmophyseter skeleton→. |
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blaze
Paleo-artist 
Posts: 766
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Post by blaze on Oct 25, 2014 7:35:13 GMT 5
Maybe the skull was taller as in Acrophyseter? as in those images previously shared by Grey
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Post by Grey on Oct 25, 2014 7:58:13 GMT 5
Yes, I think the skull was slightly taller than that (the spermaceti chamber). Several versions. 16 m :  13.5 m :   |
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Post by Grey on Oct 25, 2014 11:21:07 GMT 5
Carcharocles megalodon (female) : 17.9 m TL (Pimiento 2013) (reconstruction based on Gottfried et al. 1996). Homo sapiens (female) : 1.7 m TL. Physeter macrocephalus (male) : 18.3 m (Shirihai 2006).  |
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Post by theropod on Oct 25, 2014 14:34:33 GMT 5
How can one go from this:  to this: Scaled at roughly the same skull lenght here, the second picture has a skull over 50% deeper than the reconstruction from the description paper. Either the author assumed dorsoventral crushing of the skull, or it was simply drawn without a reference at hand. I’ve looked at the description and the supplement and found no mention of taphonomic distortion, and it seems unlikely since it preserves the curvature of the upper jaw just fine and the outline isn’t distorted/assymetric either. The skull of this thing→ would have almost twice the volume (about 7.92m³) that my version based on the published reconstruction has. They can be aligned in top view, but the lateral shapes and the proportions just don’t compare. I get about 42m³ for the trunk+skull volume of that model btw (not including the fluke and flippers), but it’s no 16m long based on superimposing the skull, just roughly 14.7m in medial lenght. That being said I highly doubt this is accurate. I can’t think of any good explanation why the skull should be 50-100% deeper than figured in the paper. or does the spermaceti-chamber add that much (about another 100% of skull depth at least)? Attachments:
liv.tar.bz2 (205 B)
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blaze
Paleo-artist
Posts: 766
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Post by blaze on Oct 25, 2014 23:28:11 GMT 5
The skull is lacking pretty much all of its dorsal part, you can see it in your figures and here.  This is how the skull looks from the front (not an orthogonal view though). Compare to a sperm whale skull seen from a somewhat similar angle.  The museum reconstruction also has a similarly tall skull. |
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Post by theropod on Oct 25, 2014 23:43:22 GMT 5
I realise that it isn’t complete, but the complete part posterior to the rostrum is convex in anterior view and sloping backwards, I just can’t see how you could get a concave (and almost vertical) anterior margin of the frontal region.
It’s true though that the temporal/parietal-whatever region could have protruded further dorsally. But would it add that huge an amount in terms of depth?
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blaze
Paleo-artist
Posts: 766
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Post by blaze on Oct 26, 2014 1:05:26 GMT 5
Maybe not that shape but I don't see anything wrong with a taller skull, the edge of the bone at the relevant part does not look like it's the actual margin despite the drawing making it look nice and smooth.
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blaze
Paleo-artist
Posts: 766
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Post by blaze on Oct 29, 2014 2:01:27 GMT 5
 Big squids |
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Post by Infinity Blade on Oct 29, 2014 2:51:16 GMT 5
Wow.
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Post by Grey on Oct 29, 2014 14:56:30 GMT 5
Big squids The colossal squid isn't estimated at up to 14 m, 500 kg ? |
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blaze
Paleo-artist
Posts: 766
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Post by blaze on Oct 29, 2014 20:20:11 GMT 5
Those are old estimates assuming similar proportions to the giant squid, but the recent specimens captured have shown that they have very short arms and tentacles. The one I have in my size chart is a composite of the heaviest and the longest captured colosal squid, the 495kg female, and a lighter one that was 5.4m in total length, both had mantle lengths of 2.5m.
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Post by theropod on Nov 15, 2014 18:40:47 GMT 5
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gigadino96
Junior Member
Vi ravviso, o luoghi ameni
Posts: 226 
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Post by gigadino96 on Nov 18, 2014 21:24:48 GMT 5
 Giant Theropods. Image made by SammerPrehistorica. Frome the left to the right: Carcharodontosaurus, Giganotosaurus, Tyrannosaurus, Spinosaurus, Mapusaurus and Acrocanthosaurus. |
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