Of course much is still unknown, but with the help of Irritator (including Angaturama) and related animals like Baryonyx and Suchomimus I feel like the general proportions are probably about correct, although there is room for uncertainty in the pectoral girdle, forelimbs, and (to a lesser extent) hindlimbs.
Edit: Tweaked the scaling on the head, as well as the rate of drop-off in the distal caudals. Ironically the animal stays about the same length, but the slightly smaller head will have consequences for people trying to estimate the length of the longest specimens.
Edit 2: Now with actual update.
what do you think?
If you want I can send to you my little diagram, or IF for you it is ok I can post here on DA...
do you think Spinosaurids had webbed feet like a duck?
Google search Suchomimus skeletons to see how bulky the body of a spinosaurid is. You'll find that they're more like bears than storks.
A more reasonable mass estimate for a ~16-meter Spinosaurus would be around ~11-13 tonnes give or take.
So basically, around ~4-8 tonnes.
Estimate fiven to the Spinosaurus holotype by Hartman, 14m, how long is Hartman's Baryonyx? 10m or so. difference, 40% or less.
They aren't that different actually, the main difference is that Cau is using a Baryonyx restored with a short skull, short torso and short tail.
I used the same GDI analysis as you and I got some interesting results to share:
Min: 11,050 kg
Average: 11,550 kg
max: 11,750 kg
This is considering a 15,6 m long specimen.
Sorry, my estimates were actually for the specimen IPHG 1912, so I decided to scale them up from 14 to 15,6 m.
If IPHG 1912 weighted 11,550 kg then MSNM V4047 should weight from 15,288 to 15,979 kg, depending in the conservative or medium estimates given.
Actually, I thought Spinosaurus had a hump, more like a camel or a bison,but when I realized this was wrong, I re-estimated the weight of the type specimen, and it weighted a full 8.4 tonnes, plus, scaled to the paratype, the full weight was 12.1 tonnes, which matches with the 8-12 tonne range for Spinosaurus.
I doubt that the paratype specimen weighted less than 10 tonnes.
Suchomimus would be a better reference point. It is closer temporally, geographically and in terms of size, plus the type specimen isn't a sub-adult (or at least it wasn't described as one, despite popular internet belief) and has proportions closer to non-spinosurid megalosauroids (e.g. Torvosaurus).