[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Baby insulation

     On the idea that dinosaur?/bird feathers and pterosaur fur are 
homologous and that all dinosaurs had the geentic potential for sporting 
feathers at least part of thier lives, I'm thinking about Greg Paul's 
paper in Dinosaur Eggs and Babies about insulation in hatchlings.8  
     Small babies exposed to the elements have a major problem 
with temeperature control, being so small.  If I am not mistaken, 
MOST endothermic animals huddle up with thier offpring at night 
to keep them warm.  Considering the size of parent 
dinosaurs, sitting on thier babies to keep them warm is not a viable option.  
The suggestion was that feather insulation was present in these hatchlings 
(perhaps to be lost at a later stage in life). How do baby ectotherms keep
from freezing?  
     However, as I noted in previous postings, this would only work if 
dinosaurs (or at least the babies) were endothermic.  Feathers and fur 
insulate, which is useful if you are generating your heat metabolically 
and don't want to loose what you are producing.  However, if you are an 
ectotherm trying to get heat from the environment, the heat would be 
absorbed by the feathers and not reach the body.  
     It there even the possibility that early feathers might have 
included some kind of blood vessel network?  If so, they may have been 
used to increase the heating surface area, a good thing for an ectotherm.  
However, it is my impression that feathers are compositionally simple 
structures (although they can be pretty complex structually), and that such a 
set up is unlikely.  If so, I think that the possesion of a covering like 
feathers or fur is a good indication of endothermy.         
     In either casse, I will be VERY interested to see what a careful 
examination of the structures on this Chinese compsognathid reveals.     

LN Jeff
"You hate people!"
"But I love gatherings.  Isn't it ironic?"