Spinosaurus News ~

[DinoFan83]

I do think the following should be noted in regards to DrZapxX's reply:

-As the abstract states, terrestrial non-avian neotheropods, despite having significantly more air sacs than Spinosaurus, are estimated to be 0.95-0.99 kg/liter. This alone would disagree with the suggestion of a density of 0.99 for Spinosaurus at most, because your suggestion implies that animals like the hyperpneumatized tyrannosauroid Aerosteon, with airsacs so extensive they invaded its ilium, furcula, and gastralia, would have a similar density to an aquatic megalosauroid that either only had a small amount of airsacs in its neck, or simply none at all. Obviously the second is going to be denser.

-As has been gone over well enough in the previous posts, simply having airsacs does not equate to a density less than that of water because the tissues themselves are a good deal denser. Like I went over above, highly pneumatized and terrestrial non-avian theropods are a good example of this (being not that far off from the density of water itself despite all those airsacs), and therefore I am more than certain that Spinosaurus would have been at least as dense as water if not more given its either very sparse or completely nonexistent airsacs.

-While crocodilians do have osteoderms that have the potential to increase their density, it seems as though diving birds (with no osteoderms and a fat layer to stay warm that there is no reasonable basis to assume Spinosaurus had, so if anything the densities for the birds are underestimates given that fat layer) are also sometimes denser than water going by Ibrahim et al. 2020's mass estimate file. 
So simply not having osteoderms does not prevent the animal to be more dense than water.

-A mere 8 tonnes is not at all realistic for a maximum size. Let's take Henderson's model for example; as was went over on Page 7 and as turned out to be precisely in agreement with what the new estimates on density suggest, it ends up over 12 tonnes (precisely 12.26) correcting the much too low density, the much too narrow torso, and no new tail. And this uses a density only equivalent to that of water; it could plausibly have been denser as was went over above.
Considering all the mass estimates and whatnot I have outlined in this thread, I consider 10-13+ tonnes to be a much more plausible range for Spinosaurus than a mere 8 tonnes. Reply