RE: Layperson question on endothermic dinosaurs

[Allan Edels <edels@msn.com>]

[Speaking as another layperson:] 

The likelihood is that the large sauropods and the larger of the ornithischians 
would feel warm to the touch.   The bigger problem for these creatures would 
need help reducing the heat retained by the large mass, as well as that 
generated by the muscles as they moved.

(Long necks and tails might have facilitated some thermal reduction, as might 
the plates on stegosaurs, etc).

I've often wondered what a good Finite Element Analysis (FEA) of the movement 
of sauropods might shine on their heat production.

Allan Edels

> Date: Wed, 15 May 2013 18:05:57 +0100
> From: mrvivianallen@googlemail.com
> To: kelly.clowers@gmail.com
> CC: dinosaur@usc.edu
> Subject: Re: Layperson question on endothermic dinosaurs
> 
> Theropods, yeah. You've got several lines of evidence that make that
> one pretty solid. Off the top of my head:
> 
> Feathers. I know feathers have other functions (display,
> water-proofing, flying eventually) but I'm going to go out on a limb
> and say one of the main things feathers do is insulate the body. Why
> would you need to insulate yourself if you were not warm-blooded?
> 
> Extensive, bird-like lungs. Most theropods had very large, complex
> breathing structures similar to those seen in birds. In birds, these
> lung complexes are very efficient at extracting a lot of oxygen from
> the air (http://en.wikipedia.org/wiki/Bird_anatomy#Respiratory_system),
> and you need a lot of oxygen to power a high metabolism. So again, why
> have these complex lung structures unless you need a lot of oxygen?
> 
> Relationship with birds. Less concrete, but the fact is that birds are
> living theropod dinosaurs, and they are endothermic. You may argue
> that this is just because they fly, but many species of birds have
> become more-or-less terrestrial, and they still maintain endothermy.
> 
> Long legs. The biomechanics behind it may be a little above layperson
> level (paper here if you are interested:
> http://www.plosone.org/article/info:doi/10.1371/journal.pone.0007783 ,
> b

> of consistent effort from quite large muscles, and to provide
> consistent energy for a lot of large muscles you need a high metabolic
> rate, i.e. are in the 'warm-blooded' part of the metabolic spectrum.
> 
> I'm sure other list members will be happy to add to the list (and
> correct me if I am wrong), but yeah, I think there is a very good case
> for endothermy in theropod dinosaurs.
> 
> In other dinosaurs (the long-necked sauropods and the very diverse
> ornithischians) it is difficult to be sure - they do not have living
> representatives, so it is more difficult to make inferences about
> their biology. But, a lot of ornithischians have similar body
> proportions to theropods, again with these long legs, which does
> indicate that they were pretty active, high-metabolism creatures.
> 
> Viv
> 
> On 15 May 2013 17:34, Kelly Clowers <kelly.clowers@gmail.com> wrote:
>> Hi, I am hoping that I could get sense of what the consensus, if any,
>> is on endothemry. I try to stay up to date and knowledgeable on all
>> things dino-related, but I just want to be clear on this to help
>> settle a discussion on the Ars Technica forums.
>>
>> I believe that it pretty solidly accepted for therapods, but maybe
>> somewhat less so for the rest? Or am I all wrong?
>>
>> Thanks very much,
>>
>> Kelly Clowers