Re: [Re: Insulation does not = "Warm-blooded"]

["Demetrios M. Vital" <vita0015@tc.umn.edu>]

David Marjanovic wrote:

> > Several insects (I don't know for spiders) are actually endothermic, or
> > partly so.

[snip]

Jurassosaurus replied:

> As for the arthropods mentioned all are probably endothermic (or partially
> endothermic), but all are also obligatory poikilotherms and are
> bradymetabolic.

If they have no "choice" but to be poikilotherms and bradymetabolic, they
aren't great examples, then.

Can we assume that obligatory poikilothermy exists at insect sizes while
obligatory gigantothermy exists at  elephant size?

> To clarify my original post, I am saying that we have living
> bradymetabolic and even poikilothermic animals that have insulation.

Is subcutaneous insulation equable to integumentary insulation?

What I'm trying to say is this:

Insects are obligatory poikilotherms, thus their use as an example for
enantiornithines and non-avian dinosaurs,  which are not necessarily
poikilothermic (hence this discussion) is very limited, indeed.  The other
two examples Jurassosaurus gave are large-sized marine animals.  Water, of
course, saps heat much more than air, by levels of magnitude.  So they are
obligatorily insulated, endothermic, and the turtle, at least, is also
bradymetabolic.

But there are no examples of terrestrial, insulated (by fat or integument,
which are not as comparable, I think, as you say), bradymetabolic,
poikilotherms.  That lack is an argument itself for terrestrial insulatory
integument being obligatorily in concert with endothermy.

-Demetrios Vital

P.S.: I don't give up, Jurassosaurus :)