Re: were dinosaurs coldblooded or warmblooded animals ?

Were dinosaurs warm blooded or cold blooded animals?

That's a good question, and one that has a lot of scientists puzzled. That 
only answer I, or anyone, can give at this time is: I don't know. But I can 
tell you about some of the clues and possibilities.

Warm blooded is a loose term for endothermic. That means the animal is able 
to keep a fairly even body temperature without having to worry about the 
weather. Mammals (animals like us) and birds are the endothermic animals 
alive today. 

Cold blooded is a loose term for exothermic. That means the animal does not 
produce heat inside its body. Instead, it has to sit in the sun to warm up 
or sit in the shade to cool down - the weather is very important to an 
exothermic animal. Reptiles are the exothermic animals alive today.

So, what difference does it make? Endothermic animals produce body heat, 
which means that they need to eat more food. It also means that they can 
move quickly at about any time of day. Exothermic animals do not produce 
body heat, which means that they do not need to eat as much foot. It also 
means that they can be very sluggish on a cold day.

So, what about dinosaurs? The question of being endothermic or exothermic 
would tell us how they lived their lives. A big animal like a dinosaur 
would require a lot of food to live, if it were exothermic it would require 
even more food. Some dinosaurs are so big, and have such small mouths, that 
it is a puzzle as to how they ate enough to stay alive. If they were 
endothermic, they would need to eat even more, which would be even more 
puzzling. Other dinosaurs seemed to live in cold environments, it takes a 
long time to heat up a big body by lying out in the sun. How could they 
have lived if they were that sluggish?

Either way you look at it, it seems to be a problem. There are a lot of 
fossil clues that can be used to argue one way or the other. But, for now, 
the scientists that work on this problem still don't know the answer.