Gigantothermic sauropods?

[dinosauria101]

So, I've been researching giantothermy a bit, and it's interesting to think about, especially considering a technically coldblooded animal to maintain a high internal temperature over a period of time.
Do you think sauropods used gigantothermy? Why or why not?

[Infinity Blade]

I recently posted a good college course page (I think Thomas R. Holtz wrote it, considering his name is in the URL and it's his university) about dinosaur metabolism. It says that gigantothermy might be possible for big dinosaurs (best for the largest sauropods, I guess), but one problem is that there's no real living analogue for it (elephants were once thought to be gigantotherms but this doesn't seem to be true, and gigantothermic sea turtles live in a completely different environment). Take that for what you will.

www.geol.umd.edu/~tholtz/G104/lectures/104endo.html

I speculate that maybe the largest sauropods could have used heterothermy like modern elephants. Maybe even mesothermy, although I have no data supporting such for giant sauropods in particular. In fact, the 2014 mesothermy paper, which I think assumes mesothermy for non-avian dinosaurs as a whole, was challenged just a year later->. Hence why it kind of annoys me that a few people from my experience have been quick to assume it as the metabolism of non-avian dinosaurs (afaik, this is the only paper, though not the only work, that championed mesothermy in non-avian dinosaurs).

[theropod]

Current consensus among people in my working group is that sauropods were tachymetabolic on at least a similar level to modern mammals, as this would be necessary in order to sustain their high growth rates. So not really any "mesothermy" there. Obviously their mass would necessarily cause some sort of inertial homeothermy or "gigantothermy", but a high metabolic rate would still be needed, so basically sauropods would rather have faced a problem with getting rid of all the heat this (and their giant fermentative guts) would produce. Long necks and air sacs have been suggested as important features adapted to radiate heat. This would also disagree with the notion that they were specifically adapted to maintain high body temperature despite a low metabolism.

[dinosauria101]

So, homeothermy and heterothermy are better guesses for sauropods, correct?

[Infinity Blade]

Well, I don't actually have hard evidence for heterothermy, hence why I said and italicized speculate.